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 struct dst_entry *ip6_negative_advice(struct dst_entry *); 91 static void ip6_dst_destroy(struct dst_entry *); 92 static void ip6_dst_ifdown(struct dst_entry *, 93 struct net_device *dev); 94 static void ip6_dst_gc(struct dst_ops *ops); 95 96 static int ip6_pkt_discard(struct sk_buff *skb); 97 static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb); 98 static int ip6_pkt_prohibit(struct sk_buff *skb); 99 static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb); 100 static void ip6_link_failure(struct sk_buff *skb); 101 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 102 struct sk_buff *skb, u32 mtu, 103 bool confirm_neigh); 104 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, 105 struct sk_buff *skb); 106 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif, 107 int strict); 108 static size_t rt6_nlmsg_size(struct fib6_info *f6i); 109 static int rt6_fill_node(struct net *net, struct sk_buff *skb, 110 struct fib6_info *rt, struct dst_entry *dst, 111 struct in6_addr *dest, struct in6_addr *src, 112 int iif, int type, u32 portid, u32 seq, 113 unsigned int flags); 114 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res, 115 const struct in6_addr *daddr, 116 const struct in6_addr *saddr); 117 118 #ifdef CONFIG_IPV6_ROUTE_INFO 119 static struct fib6_info *rt6_add_route_info(struct net *net, 120 const struct in6_addr *prefix, int prefixlen, 121 const struct in6_addr *gwaddr, 122 struct net_device *dev, 123 unsigned int pref); 124 static struct fib6_info *rt6_get_route_info(struct net *net, 125 const struct in6_addr *prefix, int prefixlen, 126 const struct in6_addr *gwaddr, 127 struct net_device *dev); 128 #endif 129 130 struct uncached_list { 131 spinlock_t lock; 132 struct list_head head; 133 struct list_head quarantine; 134 }; 135 136 static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list); 137 138 void rt6_uncached_list_add(struct rt6_info *rt) 139 { 140 struct uncached_list *ul = raw_cpu_ptr(&rt6_uncached_list); 141 142 rt->dst.rt_uncached_list = ul; 143 144 spin_lock_bh(&ul->lock); 145 list_add_tail(&rt->dst.rt_uncached, &ul->head); 146 spin_unlock_bh(&ul->lock); 147 } 148 149 void rt6_uncached_list_del(struct rt6_info *rt) 150 { 151 if (!list_empty(&rt->dst.rt_uncached)) { 152 struct uncached_list *ul = rt->dst.rt_uncached_list; 153 154 spin_lock_bh(&ul->lock); 155 list_del_init(&rt->dst.rt_uncached); 156 spin_unlock_bh(&ul->lock); 157 } 158 } 159 160 static void rt6_uncached_list_flush_dev(struct net_device *dev) 161 { 162 int cpu; 163 164 for_each_possible_cpu(cpu) { 165 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu); 166 struct rt6_info *rt, *safe; 167 168 if (list_empty(&ul->head)) 169 continue; 170 171 spin_lock_bh(&ul->lock); 172 list_for_each_entry_safe(rt, safe, &ul->head, dst.rt_uncached) { 173 struct inet6_dev *rt_idev = rt->rt6i_idev; 174 struct net_device *rt_dev = rt->dst.dev; 175 bool handled = false; 176 177 if (rt_idev->dev == dev) { 178 rt->rt6i_idev = in6_dev_get(blackhole_netdev); 179 in6_dev_put(rt_idev); 180 handled = true; 181 } 182 183 if (rt_dev == dev) { 184 rt->dst.dev = blackhole_netdev; 185 netdev_ref_replace(rt_dev, blackhole_netdev, 186 &rt->dst.dev_tracker, 187 GFP_ATOMIC); 188 handled = true; 189 } 190 if (handled) 191 list_move(&rt->dst.rt_uncached, 192 &ul->quarantine); 193 } 194 spin_unlock_bh(&ul->lock); 195 } 196 } 197 198 static inline const void *choose_neigh_daddr(const struct in6_addr *p, 199 struct sk_buff *skb, 200 const void *daddr) 201 { 202 if (!ipv6_addr_any(p)) 203 return (const void *) p; 204 else if (skb) 205 return &ipv6_hdr(skb)->daddr; 206 return daddr; 207 } 208 209 struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw, 210 struct net_device *dev, 211 struct sk_buff *skb, 212 const void *daddr) 213 { 214 struct neighbour *n; 215 216 daddr = choose_neigh_daddr(gw, skb, daddr); 217 n = __ipv6_neigh_lookup(dev, daddr); 218 if (n) 219 return n; 220 221 n = neigh_create(&nd_tbl, daddr, dev); 222 return IS_ERR(n) ? NULL : n; 223 } 224 225 static struct neighbour *ip6_dst_neigh_lookup(const struct dst_entry *dst, 226 struct sk_buff *skb, 227 const void *daddr) 228 { 229 const struct rt6_info *rt = container_of(dst, struct rt6_info, dst); 230 231 return ip6_neigh_lookup(rt6_nexthop(rt, &in6addr_any), 232 dst->dev, skb, daddr); 233 } 234 235 static void ip6_confirm_neigh(const struct dst_entry *dst, const void *daddr) 236 { 237 struct net_device *dev = dst->dev; 238 struct rt6_info *rt = (struct rt6_info *)dst; 239 240 daddr = choose_neigh_daddr(rt6_nexthop(rt, &in6addr_any), NULL, daddr); 241 if (!daddr) 242 return; 243 if (dev->flags & (IFF_NOARP | IFF_LOOPBACK)) 244 return; 245 if (ipv6_addr_is_multicast((const struct in6_addr *)daddr)) 246 return; 247 __ipv6_confirm_neigh(dev, daddr); 248 } 249 250 static struct dst_ops ip6_dst_ops_template = { 251 .family = AF_INET6, 252 .gc = ip6_dst_gc, 253 .gc_thresh = 1024, 254 .check = ip6_dst_check, 255 .default_advmss = ip6_default_advmss, 256 .mtu = ip6_mtu, 257 .cow_metrics = dst_cow_metrics_generic, 258 .destroy = ip6_dst_destroy, 259 .ifdown = ip6_dst_ifdown, 260 .negative_advice = ip6_negative_advice, 261 .link_failure = ip6_link_failure, 262 .update_pmtu = ip6_rt_update_pmtu, 263 .redirect = rt6_do_redirect, 264 .local_out = __ip6_local_out, 265 .neigh_lookup = ip6_dst_neigh_lookup, 266 .confirm_neigh = ip6_confirm_neigh, 267 }; 268 269 static struct dst_ops ip6_dst_blackhole_ops = { 270 .family = AF_INET6, 271 .default_advmss = ip6_default_advmss, 272 .neigh_lookup = ip6_dst_neigh_lookup, 273 .check = ip6_dst_check, 274 .destroy = ip6_dst_destroy, 275 .cow_metrics = dst_cow_metrics_generic, 276 .update_pmtu = dst_blackhole_update_pmtu, 277 .redirect = dst_blackhole_redirect, 278 .mtu = dst_blackhole_mtu, 279 }; 280 281 static const u32 ip6_template_metrics[RTAX_MAX] = { 282 [RTAX_HOPLIMIT - 1] = 0, 283 }; 284 285 static const struct fib6_info fib6_null_entry_template = { 286 .fib6_flags = (RTF_REJECT | RTF_NONEXTHOP), 287 .fib6_protocol = RTPROT_KERNEL, 288 .fib6_metric = ~(u32)0, 289 .fib6_ref = REFCOUNT_INIT(1), 290 .fib6_type = RTN_UNREACHABLE, 291 .fib6_metrics = (struct dst_metrics *)&dst_default_metrics, 292 }; 293 294 static const struct rt6_info ip6_null_entry_template = { 295 .dst = { 296 .__rcuref = RCUREF_INIT(1), 297 .__use = 1, 298 .obsolete = DST_OBSOLETE_FORCE_CHK, 299 .error = -ENETUNREACH, 300 .input = ip6_pkt_discard, 301 .output = ip6_pkt_discard_out, 302 }, 303 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), 304 }; 305 306 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 307 308 static const struct rt6_info ip6_prohibit_entry_template = { 309 .dst = { 310 .__rcuref = RCUREF_INIT(1), 311 .__use = 1, 312 .obsolete = DST_OBSOLETE_FORCE_CHK, 313 .error = -EACCES, 314 .input = ip6_pkt_prohibit, 315 .output = ip6_pkt_prohibit_out, 316 }, 317 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), 318 }; 319 320 static const struct rt6_info ip6_blk_hole_entry_template = { 321 .dst = { 322 .__rcuref = RCUREF_INIT(1), 323 .__use = 1, 324 .obsolete = DST_OBSOLETE_FORCE_CHK, 325 .error = -EINVAL, 326 .input = dst_discard, 327 .output = dst_discard_out, 328 }, 329 .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), 330 }; 331 332 #endif 333 334 static void rt6_info_init(struct rt6_info *rt) 335 { 336 memset_after(rt, 0, dst); 337 } 338 339 /* allocate dst with ip6_dst_ops */ 340 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev, 341 int flags) 342 { 343 struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev, 344 1, DST_OBSOLETE_FORCE_CHK, flags); 345 346 if (rt) { 347 rt6_info_init(rt); 348 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc); 349 } 350 351 return rt; 352 } 353 EXPORT_SYMBOL(ip6_dst_alloc); 354 355 static void ip6_dst_destroy(struct dst_entry *dst) 356 { 357 struct rt6_info *rt = (struct rt6_info *)dst; 358 struct fib6_info *from; 359 struct inet6_dev *idev; 360 361 ip_dst_metrics_put(dst); 362 rt6_uncached_list_del(rt); 363 364 idev = rt->rt6i_idev; 365 if (idev) { 366 rt->rt6i_idev = NULL; 367 in6_dev_put(idev); 368 } 369 370 from = xchg((__force struct fib6_info **)&rt->from, NULL); 371 fib6_info_release(from); 372 } 373 374 static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev) 375 { 376 struct rt6_info *rt = (struct rt6_info *)dst; 377 struct inet6_dev *idev = rt->rt6i_idev; 378 379 if (idev && idev->dev != blackhole_netdev) { 380 struct inet6_dev *blackhole_idev = in6_dev_get(blackhole_netdev); 381 382 if (blackhole_idev) { 383 rt->rt6i_idev = blackhole_idev; 384 in6_dev_put(idev); 385 } 386 } 387 } 388 389 static bool __rt6_check_expired(const struct rt6_info *rt) 390 { 391 if (rt->rt6i_flags & RTF_EXPIRES) 392 return time_after(jiffies, rt->dst.expires); 393 else 394 return false; 395 } 396 397 static bool rt6_check_expired(const struct rt6_info *rt) 398 { 399 struct fib6_info *from; 400 401 from = rcu_dereference(rt->from); 402 403 if (rt->rt6i_flags & RTF_EXPIRES) { 404 if (time_after(jiffies, rt->dst.expires)) 405 return true; 406 } else if (from) { 407 return rt->dst.obsolete != DST_OBSOLETE_FORCE_CHK || 408 fib6_check_expired(from); 409 } 410 return false; 411 } 412 413 void fib6_select_path(const struct net *net, struct fib6_result *res, 414 struct flowi6 *fl6, int oif, bool have_oif_match, 415 const struct sk_buff *skb, int strict) 416 { 417 struct fib6_info *sibling, *next_sibling; 418 struct fib6_info *match = res->f6i; 419 420 if (!match->nh && (!match->fib6_nsiblings || have_oif_match)) 421 goto out; 422 423 if (match->nh && have_oif_match && res->nh) 424 return; 425 426 /* We might have already computed the hash for ICMPv6 errors. In such 427 * case it will always be non-zero. Otherwise now is the time to do it. 428 */ 429 if (!fl6->mp_hash && 430 (!match->nh || nexthop_is_multipath(match->nh))) 431 fl6->mp_hash = rt6_multipath_hash(net, fl6, skb, NULL); 432 433 if (unlikely(match->nh)) { 434 nexthop_path_fib6_result(res, fl6->mp_hash); 435 return; 436 } 437 438 if (fl6->mp_hash <= atomic_read(&match->fib6_nh->fib_nh_upper_bound)) 439 goto out; 440 441 list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings, 442 fib6_siblings) { 443 const struct fib6_nh *nh = sibling->fib6_nh; 444 int nh_upper_bound; 445 446 nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound); 447 if (fl6->mp_hash > nh_upper_bound) 448 continue; 449 if (rt6_score_route(nh, sibling->fib6_flags, oif, strict) < 0) 450 break; 451 match = sibling; 452 break; 453 } 454 455 out: 456 res->f6i = match; 457 res->nh = match->fib6_nh; 458 } 459 460 /* 461 * Route lookup. rcu_read_lock() should be held. 462 */ 463 464 static bool __rt6_device_match(struct net *net, const struct fib6_nh *nh, 465 const struct in6_addr *saddr, int oif, int flags) 466 { 467 const struct net_device *dev; 468 469 if (nh->fib_nh_flags & RTNH_F_DEAD) 470 return false; 471 472 dev = nh->fib_nh_dev; 473 if (oif) { 474 if (dev->ifindex == oif) 475 return true; 476 } else { 477 if (ipv6_chk_addr(net, saddr, dev, 478 flags & RT6_LOOKUP_F_IFACE)) 479 return true; 480 } 481 482 return false; 483 } 484 485 struct fib6_nh_dm_arg { 486 struct net *net; 487 const struct in6_addr *saddr; 488 int oif; 489 int flags; 490 struct fib6_nh *nh; 491 }; 492 493 static int __rt6_nh_dev_match(struct fib6_nh *nh, void *_arg) 494 { 495 struct fib6_nh_dm_arg *arg = _arg; 496 497 arg->nh = nh; 498 return __rt6_device_match(arg->net, nh, arg->saddr, arg->oif, 499 arg->flags); 500 } 501 502 /* returns fib6_nh from nexthop or NULL */ 503 static struct fib6_nh *rt6_nh_dev_match(struct net *net, struct nexthop *nh, 504 struct fib6_result *res, 505 const struct in6_addr *saddr, 506 int oif, int flags) 507 { 508 struct fib6_nh_dm_arg arg = { 509 .net = net, 510 .saddr = saddr, 511 .oif = oif, 512 .flags = flags, 513 }; 514 515 if (nexthop_is_blackhole(nh)) 516 return NULL; 517 518 if (nexthop_for_each_fib6_nh(nh, __rt6_nh_dev_match, &arg)) 519 return arg.nh; 520 521 return NULL; 522 } 523 524 static void rt6_device_match(struct net *net, struct fib6_result *res, 525 const struct in6_addr *saddr, int oif, int flags) 526 { 527 struct fib6_info *f6i = res->f6i; 528 struct fib6_info *spf6i; 529 struct fib6_nh *nh; 530 531 if (!oif && ipv6_addr_any(saddr)) { 532 if (unlikely(f6i->nh)) { 533 nh = nexthop_fib6_nh(f6i->nh); 534 if (nexthop_is_blackhole(f6i->nh)) 535 goto out_blackhole; 536 } else { 537 nh = f6i->fib6_nh; 538 } 539 if (!(nh->fib_nh_flags & RTNH_F_DEAD)) 540 goto out; 541 } 542 543 for (spf6i = f6i; spf6i; spf6i = rcu_dereference(spf6i->fib6_next)) { 544 bool matched = false; 545 546 if (unlikely(spf6i->nh)) { 547 nh = rt6_nh_dev_match(net, spf6i->nh, res, saddr, 548 oif, flags); 549 if (nh) 550 matched = true; 551 } else { 552 nh = spf6i->fib6_nh; 553 if (__rt6_device_match(net, nh, saddr, oif, flags)) 554 matched = true; 555 } 556 if (matched) { 557 res->f6i = spf6i; 558 goto out; 559 } 560 } 561 562 if (oif && flags & RT6_LOOKUP_F_IFACE) { 563 res->f6i = net->ipv6.fib6_null_entry; 564 nh = res->f6i->fib6_nh; 565 goto out; 566 } 567 568 if (unlikely(f6i->nh)) { 569 nh = nexthop_fib6_nh(f6i->nh); 570 if (nexthop_is_blackhole(f6i->nh)) 571 goto out_blackhole; 572 } else { 573 nh = f6i->fib6_nh; 574 } 575 576 if (nh->fib_nh_flags & RTNH_F_DEAD) { 577 res->f6i = net->ipv6.fib6_null_entry; 578 nh = res->f6i->fib6_nh; 579 } 580 out: 581 res->nh = nh; 582 res->fib6_type = res->f6i->fib6_type; 583 res->fib6_flags = res->f6i->fib6_flags; 584 return; 585 586 out_blackhole: 587 res->fib6_flags |= RTF_REJECT; 588 res->fib6_type = RTN_BLACKHOLE; 589 res->nh = nh; 590 } 591 592 #ifdef CONFIG_IPV6_ROUTER_PREF 593 struct __rt6_probe_work { 594 struct work_struct work; 595 struct in6_addr target; 596 struct net_device *dev; 597 netdevice_tracker dev_tracker; 598 }; 599 600 static void rt6_probe_deferred(struct work_struct *w) 601 { 602 struct in6_addr mcaddr; 603 struct __rt6_probe_work *work = 604 container_of(w, struct __rt6_probe_work, work); 605 606 addrconf_addr_solict_mult(&work->target, &mcaddr); 607 ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL, 0); 608 netdev_put(work->dev, &work->dev_tracker); 609 kfree(work); 610 } 611 612 static void rt6_probe(struct fib6_nh *fib6_nh) 613 { 614 struct __rt6_probe_work *work = NULL; 615 const struct in6_addr *nh_gw; 616 unsigned long last_probe; 617 struct neighbour *neigh; 618 struct net_device *dev; 619 struct inet6_dev *idev; 620 621 /* 622 * Okay, this does not seem to be appropriate 623 * for now, however, we need to check if it 624 * is really so; aka Router Reachability Probing. 625 * 626 * Router Reachability Probe MUST be rate-limited 627 * to no more than one per minute. 628 */ 629 if (!fib6_nh->fib_nh_gw_family) 630 return; 631 632 nh_gw = &fib6_nh->fib_nh_gw6; 633 dev = fib6_nh->fib_nh_dev; 634 rcu_read_lock(); 635 last_probe = READ_ONCE(fib6_nh->last_probe); 636 idev = __in6_dev_get(dev); 637 neigh = __ipv6_neigh_lookup_noref(dev, nh_gw); 638 if (neigh) { 639 if (READ_ONCE(neigh->nud_state) & NUD_VALID) 640 goto out; 641 642 write_lock_bh(&neigh->lock); 643 if (!(neigh->nud_state & NUD_VALID) && 644 time_after(jiffies, 645 neigh->updated + idev->cnf.rtr_probe_interval)) { 646 work = kmalloc(sizeof(*work), GFP_ATOMIC); 647 if (work) 648 __neigh_set_probe_once(neigh); 649 } 650 write_unlock_bh(&neigh->lock); 651 } else if (time_after(jiffies, last_probe + 652 idev->cnf.rtr_probe_interval)) { 653 work = kmalloc(sizeof(*work), GFP_ATOMIC); 654 } 655 656 if (!work || cmpxchg(&fib6_nh->last_probe, 657 last_probe, jiffies) != last_probe) { 658 kfree(work); 659 } else { 660 INIT_WORK(&work->work, rt6_probe_deferred); 661 work->target = *nh_gw; 662 netdev_hold(dev, &work->dev_tracker, GFP_ATOMIC); 663 work->dev = dev; 664 schedule_work(&work->work); 665 } 666 667 out: 668 rcu_read_unlock(); 669 } 670 #else 671 static inline void rt6_probe(struct fib6_nh *fib6_nh) 672 { 673 } 674 #endif 675 676 /* 677 * Default Router Selection (RFC 2461 6.3.6) 678 */ 679 static enum rt6_nud_state rt6_check_neigh(const struct fib6_nh *fib6_nh) 680 { 681 enum rt6_nud_state ret = RT6_NUD_FAIL_HARD; 682 struct neighbour *neigh; 683 684 rcu_read_lock(); 685 neigh = __ipv6_neigh_lookup_noref(fib6_nh->fib_nh_dev, 686 &fib6_nh->fib_nh_gw6); 687 if (neigh) { 688 u8 nud_state = READ_ONCE(neigh->nud_state); 689 690 if (nud_state & NUD_VALID) 691 ret = RT6_NUD_SUCCEED; 692 #ifdef CONFIG_IPV6_ROUTER_PREF 693 else if (!(nud_state & NUD_FAILED)) 694 ret = RT6_NUD_SUCCEED; 695 else 696 ret = RT6_NUD_FAIL_PROBE; 697 #endif 698 } else { 699 ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ? 700 RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR; 701 } 702 rcu_read_unlock(); 703 704 return ret; 705 } 706 707 static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif, 708 int strict) 709 { 710 int m = 0; 711 712 if (!oif || nh->fib_nh_dev->ifindex == oif) 713 m = 2; 714 715 if (!m && (strict & RT6_LOOKUP_F_IFACE)) 716 return RT6_NUD_FAIL_HARD; 717 #ifdef CONFIG_IPV6_ROUTER_PREF 718 m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(fib6_flags)) << 2; 719 #endif 720 if ((strict & RT6_LOOKUP_F_REACHABLE) && 721 !(fib6_flags & RTF_NONEXTHOP) && nh->fib_nh_gw_family) { 722 int n = rt6_check_neigh(nh); 723 if (n < 0) 724 return n; 725 } 726 return m; 727 } 728 729 static bool find_match(struct fib6_nh *nh, u32 fib6_flags, 730 int oif, int strict, int *mpri, bool *do_rr) 731 { 732 bool match_do_rr = false; 733 bool rc = false; 734 int m; 735 736 if (nh->fib_nh_flags & RTNH_F_DEAD) 737 goto out; 738 739 if (ip6_ignore_linkdown(nh->fib_nh_dev) && 740 nh->fib_nh_flags & RTNH_F_LINKDOWN && 741 !(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE)) 742 goto out; 743 744 m = rt6_score_route(nh, fib6_flags, oif, strict); 745 if (m == RT6_NUD_FAIL_DO_RR) { 746 match_do_rr = true; 747 m = 0; /* lowest valid score */ 748 } else if (m == RT6_NUD_FAIL_HARD) { 749 goto out; 750 } 751 752 if (strict & RT6_LOOKUP_F_REACHABLE) 753 rt6_probe(nh); 754 755 /* note that m can be RT6_NUD_FAIL_PROBE at this point */ 756 if (m > *mpri) { 757 *do_rr = match_do_rr; 758 *mpri = m; 759 rc = true; 760 } 761 out: 762 return rc; 763 } 764 765 struct fib6_nh_frl_arg { 766 u32 flags; 767 int oif; 768 int strict; 769 int *mpri; 770 bool *do_rr; 771 struct fib6_nh *nh; 772 }; 773 774 static int rt6_nh_find_match(struct fib6_nh *nh, void *_arg) 775 { 776 struct fib6_nh_frl_arg *arg = _arg; 777 778 arg->nh = nh; 779 return find_match(nh, arg->flags, arg->oif, arg->strict, 780 arg->mpri, arg->do_rr); 781 } 782 783 static void __find_rr_leaf(struct fib6_info *f6i_start, 784 struct fib6_info *nomatch, u32 metric, 785 struct fib6_result *res, struct fib6_info **cont, 786 int oif, int strict, bool *do_rr, int *mpri) 787 { 788 struct fib6_info *f6i; 789 790 for (f6i = f6i_start; 791 f6i && f6i != nomatch; 792 f6i = rcu_dereference(f6i->fib6_next)) { 793 bool matched = false; 794 struct fib6_nh *nh; 795 796 if (cont && f6i->fib6_metric != metric) { 797 *cont = f6i; 798 return; 799 } 800 801 if (fib6_check_expired(f6i)) 802 continue; 803 804 if (unlikely(f6i->nh)) { 805 struct fib6_nh_frl_arg arg = { 806 .flags = f6i->fib6_flags, 807 .oif = oif, 808 .strict = strict, 809 .mpri = mpri, 810 .do_rr = do_rr 811 }; 812 813 if (nexthop_is_blackhole(f6i->nh)) { 814 res->fib6_flags = RTF_REJECT; 815 res->fib6_type = RTN_BLACKHOLE; 816 res->f6i = f6i; 817 res->nh = nexthop_fib6_nh(f6i->nh); 818 return; 819 } 820 if (nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_find_match, 821 &arg)) { 822 matched = true; 823 nh = arg.nh; 824 } 825 } else { 826 nh = f6i->fib6_nh; 827 if (find_match(nh, f6i->fib6_flags, oif, strict, 828 mpri, do_rr)) 829 matched = true; 830 } 831 if (matched) { 832 res->f6i = f6i; 833 res->nh = nh; 834 res->fib6_flags = f6i->fib6_flags; 835 res->fib6_type = f6i->fib6_type; 836 } 837 } 838 } 839 840 static void find_rr_leaf(struct fib6_node *fn, struct fib6_info *leaf, 841 struct fib6_info *rr_head, int oif, int strict, 842 bool *do_rr, struct fib6_result *res) 843 { 844 u32 metric = rr_head->fib6_metric; 845 struct fib6_info *cont = NULL; 846 int mpri = -1; 847 848 __find_rr_leaf(rr_head, NULL, metric, res, &cont, 849 oif, strict, do_rr, &mpri); 850 851 __find_rr_leaf(leaf, rr_head, metric, res, &cont, 852 oif, strict, do_rr, &mpri); 853 854 if (res->f6i || !cont) 855 return; 856 857 __find_rr_leaf(cont, NULL, metric, res, NULL, 858 oif, strict, do_rr, &mpri); 859 } 860 861 static void rt6_select(struct net *net, struct fib6_node *fn, int oif, 862 struct fib6_result *res, int strict) 863 { 864 struct fib6_info *leaf = rcu_dereference(fn->leaf); 865 struct fib6_info *rt0; 866 bool do_rr = false; 867 int key_plen; 868 869 /* make sure this function or its helpers sets f6i */ 870 res->f6i = NULL; 871 872 if (!leaf || leaf == net->ipv6.fib6_null_entry) 873 goto out; 874 875 rt0 = rcu_dereference(fn->rr_ptr); 876 if (!rt0) 877 rt0 = leaf; 878 879 /* Double check to make sure fn is not an intermediate node 880 * and fn->leaf does not points to its child's leaf 881 * (This might happen if all routes under fn are deleted from 882 * the tree and fib6_repair_tree() is called on the node.) 883 */ 884 key_plen = rt0->fib6_dst.plen; 885 #ifdef CONFIG_IPV6_SUBTREES 886 if (rt0->fib6_src.plen) 887 key_plen = rt0->fib6_src.plen; 888 #endif 889 if (fn->fn_bit != key_plen) 890 goto out; 891 892 find_rr_leaf(fn, leaf, rt0, oif, strict, &do_rr, res); 893 if (do_rr) { 894 struct fib6_info *next = rcu_dereference(rt0->fib6_next); 895 896 /* no entries matched; do round-robin */ 897 if (!next || next->fib6_metric != rt0->fib6_metric) 898 next = leaf; 899 900 if (next != rt0) { 901 spin_lock_bh(&leaf->fib6_table->tb6_lock); 902 /* make sure next is not being deleted from the tree */ 903 if (next->fib6_node) 904 rcu_assign_pointer(fn->rr_ptr, next); 905 spin_unlock_bh(&leaf->fib6_table->tb6_lock); 906 } 907 } 908 909 out: 910 if (!res->f6i) { 911 res->f6i = net->ipv6.fib6_null_entry; 912 res->nh = res->f6i->fib6_nh; 913 res->fib6_flags = res->f6i->fib6_flags; 914 res->fib6_type = res->f6i->fib6_type; 915 } 916 } 917 918 static bool rt6_is_gw_or_nonexthop(const struct fib6_result *res) 919 { 920 return (res->f6i->fib6_flags & RTF_NONEXTHOP) || 921 res->nh->fib_nh_gw_family; 922 } 923 924 #ifdef CONFIG_IPV6_ROUTE_INFO 925 int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, 926 const struct in6_addr *gwaddr) 927 { 928 struct net *net = dev_net(dev); 929 struct route_info *rinfo = (struct route_info *) opt; 930 struct in6_addr prefix_buf, *prefix; 931 unsigned int pref; 932 unsigned long lifetime; 933 struct fib6_info *rt; 934 935 if (len < sizeof(struct route_info)) { 936 return -EINVAL; 937 } 938 939 /* Sanity check for prefix_len and length */ 940 if (rinfo->length > 3) { 941 return -EINVAL; 942 } else if (rinfo->prefix_len > 128) { 943 return -EINVAL; 944 } else if (rinfo->prefix_len > 64) { 945 if (rinfo->length < 2) { 946 return -EINVAL; 947 } 948 } else if (rinfo->prefix_len > 0) { 949 if (rinfo->length < 1) { 950 return -EINVAL; 951 } 952 } 953 954 pref = rinfo->route_pref; 955 if (pref == ICMPV6_ROUTER_PREF_INVALID) 956 return -EINVAL; 957 958 lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ); 959 960 if (rinfo->length == 3) 961 prefix = (struct in6_addr *)rinfo->prefix; 962 else { 963 /* this function is safe */ 964 ipv6_addr_prefix(&prefix_buf, 965 (struct in6_addr *)rinfo->prefix, 966 rinfo->prefix_len); 967 prefix = &prefix_buf; 968 } 969 970 if (rinfo->prefix_len == 0) 971 rt = rt6_get_dflt_router(net, gwaddr, dev); 972 else 973 rt = rt6_get_route_info(net, prefix, rinfo->prefix_len, 974 gwaddr, dev); 975 976 if (rt && !lifetime) { 977 ip6_del_rt(net, rt, false); 978 rt = NULL; 979 } 980 981 if (!rt && lifetime) 982 rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr, 983 dev, pref); 984 else if (rt) 985 rt->fib6_flags = RTF_ROUTEINFO | 986 (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); 987 988 if (rt) { 989 if (!addrconf_finite_timeout(lifetime)) 990 fib6_clean_expires(rt); 991 else 992 fib6_set_expires(rt, jiffies + HZ * lifetime); 993 994 fib6_info_release(rt); 995 } 996 return 0; 997 } 998 #endif 999 1000 /* 1001 * Misc support functions 1002 */ 1003 1004 /* called with rcu_lock held */ 1005 static struct net_device *ip6_rt_get_dev_rcu(const struct fib6_result *res) 1006 { 1007 struct net_device *dev = res->nh->fib_nh_dev; 1008 1009 if (res->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) { 1010 /* for copies of local routes, dst->dev needs to be the 1011 * device if it is a master device, the master device if 1012 * device is enslaved, and the loopback as the default 1013 */ 1014 if (netif_is_l3_slave(dev) && 1015 !rt6_need_strict(&res->f6i->fib6_dst.addr)) 1016 dev = l3mdev_master_dev_rcu(dev); 1017 else if (!netif_is_l3_master(dev)) 1018 dev = dev_net(dev)->loopback_dev; 1019 /* last case is netif_is_l3_master(dev) is true in which 1020 * case we want dev returned to be dev 1021 */ 1022 } 1023 1024 return dev; 1025 } 1026 1027 static const int fib6_prop[RTN_MAX + 1] = { 1028 [RTN_UNSPEC] = 0, 1029 [RTN_UNICAST] = 0, 1030 [RTN_LOCAL] = 0, 1031 [RTN_BROADCAST] = 0, 1032 [RTN_ANYCAST] = 0, 1033 [RTN_MULTICAST] = 0, 1034 [RTN_BLACKHOLE] = -EINVAL, 1035 [RTN_UNREACHABLE] = -EHOSTUNREACH, 1036 [RTN_PROHIBIT] = -EACCES, 1037 [RTN_THROW] = -EAGAIN, 1038 [RTN_NAT] = -EINVAL, 1039 [RTN_XRESOLVE] = -EINVAL, 1040 }; 1041 1042 static int ip6_rt_type_to_error(u8 fib6_type) 1043 { 1044 return fib6_prop[fib6_type]; 1045 } 1046 1047 static unsigned short fib6_info_dst_flags(struct fib6_info *rt) 1048 { 1049 unsigned short flags = 0; 1050 1051 if (rt->dst_nocount) 1052 flags |= DST_NOCOUNT; 1053 if (rt->dst_nopolicy) 1054 flags |= DST_NOPOLICY; 1055 1056 return flags; 1057 } 1058 1059 static void ip6_rt_init_dst_reject(struct rt6_info *rt, u8 fib6_type) 1060 { 1061 rt->dst.error = ip6_rt_type_to_error(fib6_type); 1062 1063 switch (fib6_type) { 1064 case RTN_BLACKHOLE: 1065 rt->dst.output = dst_discard_out; 1066 rt->dst.input = dst_discard; 1067 break; 1068 case RTN_PROHIBIT: 1069 rt->dst.output = ip6_pkt_prohibit_out; 1070 rt->dst.input = ip6_pkt_prohibit; 1071 break; 1072 case RTN_THROW: 1073 case RTN_UNREACHABLE: 1074 default: 1075 rt->dst.output = ip6_pkt_discard_out; 1076 rt->dst.input = ip6_pkt_discard; 1077 break; 1078 } 1079 } 1080 1081 static void ip6_rt_init_dst(struct rt6_info *rt, const struct fib6_result *res) 1082 { 1083 struct fib6_info *f6i = res->f6i; 1084 1085 if (res->fib6_flags & RTF_REJECT) { 1086 ip6_rt_init_dst_reject(rt, res->fib6_type); 1087 return; 1088 } 1089 1090 rt->dst.error = 0; 1091 rt->dst.output = ip6_output; 1092 1093 if (res->fib6_type == RTN_LOCAL || res->fib6_type == RTN_ANYCAST) { 1094 rt->dst.input = ip6_input; 1095 } else if (ipv6_addr_type(&f6i->fib6_dst.addr) & IPV6_ADDR_MULTICAST) { 1096 rt->dst.input = ip6_mc_input; 1097 } else { 1098 rt->dst.input = ip6_forward; 1099 } 1100 1101 if (res->nh->fib_nh_lws) { 1102 rt->dst.lwtstate = lwtstate_get(res->nh->fib_nh_lws); 1103 lwtunnel_set_redirect(&rt->dst); 1104 } 1105 1106 rt->dst.lastuse = jiffies; 1107 } 1108 1109 /* Caller must already hold reference to @from */ 1110 static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from) 1111 { 1112 rt->rt6i_flags &= ~RTF_EXPIRES; 1113 rcu_assign_pointer(rt->from, from); 1114 ip_dst_init_metrics(&rt->dst, from->fib6_metrics); 1115 } 1116 1117 /* Caller must already hold reference to f6i in result */ 1118 static void ip6_rt_copy_init(struct rt6_info *rt, const struct fib6_result *res) 1119 { 1120 const struct fib6_nh *nh = res->nh; 1121 const struct net_device *dev = nh->fib_nh_dev; 1122 struct fib6_info *f6i = res->f6i; 1123 1124 ip6_rt_init_dst(rt, res); 1125 1126 rt->rt6i_dst = f6i->fib6_dst; 1127 rt->rt6i_idev = dev ? in6_dev_get(dev) : NULL; 1128 rt->rt6i_flags = res->fib6_flags; 1129 if (nh->fib_nh_gw_family) { 1130 rt->rt6i_gateway = nh->fib_nh_gw6; 1131 rt->rt6i_flags |= RTF_GATEWAY; 1132 } 1133 rt6_set_from(rt, f6i); 1134 #ifdef CONFIG_IPV6_SUBTREES 1135 rt->rt6i_src = f6i->fib6_src; 1136 #endif 1137 } 1138 1139 static struct fib6_node* fib6_backtrack(struct fib6_node *fn, 1140 struct in6_addr *saddr) 1141 { 1142 struct fib6_node *pn, *sn; 1143 while (1) { 1144 if (fn->fn_flags & RTN_TL_ROOT) 1145 return NULL; 1146 pn = rcu_dereference(fn->parent); 1147 sn = FIB6_SUBTREE(pn); 1148 if (sn && sn != fn) 1149 fn = fib6_node_lookup(sn, NULL, saddr); 1150 else 1151 fn = pn; 1152 if (fn->fn_flags & RTN_RTINFO) 1153 return fn; 1154 } 1155 } 1156 1157 static bool ip6_hold_safe(struct net *net, struct rt6_info **prt) 1158 { 1159 struct rt6_info *rt = *prt; 1160 1161 if (dst_hold_safe(&rt->dst)) 1162 return true; 1163 if (net) { 1164 rt = net->ipv6.ip6_null_entry; 1165 dst_hold(&rt->dst); 1166 } else { 1167 rt = NULL; 1168 } 1169 *prt = rt; 1170 return false; 1171 } 1172 1173 /* called with rcu_lock held */ 1174 static struct rt6_info *ip6_create_rt_rcu(const struct fib6_result *res) 1175 { 1176 struct net_device *dev = res->nh->fib_nh_dev; 1177 struct fib6_info *f6i = res->f6i; 1178 unsigned short flags; 1179 struct rt6_info *nrt; 1180 1181 if (!fib6_info_hold_safe(f6i)) 1182 goto fallback; 1183 1184 flags = fib6_info_dst_flags(f6i); 1185 nrt = ip6_dst_alloc(dev_net(dev), dev, flags); 1186 if (!nrt) { 1187 fib6_info_release(f6i); 1188 goto fallback; 1189 } 1190 1191 ip6_rt_copy_init(nrt, res); 1192 return nrt; 1193 1194 fallback: 1195 nrt = dev_net(dev)->ipv6.ip6_null_entry; 1196 dst_hold(&nrt->dst); 1197 return nrt; 1198 } 1199 1200 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_lookup(struct net *net, 1201 struct fib6_table *table, 1202 struct flowi6 *fl6, 1203 const struct sk_buff *skb, 1204 int flags) 1205 { 1206 struct fib6_result res = {}; 1207 struct fib6_node *fn; 1208 struct rt6_info *rt; 1209 1210 rcu_read_lock(); 1211 fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); 1212 restart: 1213 res.f6i = rcu_dereference(fn->leaf); 1214 if (!res.f6i) 1215 res.f6i = net->ipv6.fib6_null_entry; 1216 else 1217 rt6_device_match(net, &res, &fl6->saddr, fl6->flowi6_oif, 1218 flags); 1219 1220 if (res.f6i == net->ipv6.fib6_null_entry) { 1221 fn = fib6_backtrack(fn, &fl6->saddr); 1222 if (fn) 1223 goto restart; 1224 1225 rt = net->ipv6.ip6_null_entry; 1226 dst_hold(&rt->dst); 1227 goto out; 1228 } else if (res.fib6_flags & RTF_REJECT) { 1229 goto do_create; 1230 } 1231 1232 fib6_select_path(net, &res, fl6, fl6->flowi6_oif, 1233 fl6->flowi6_oif != 0, skb, flags); 1234 1235 /* Search through exception table */ 1236 rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr); 1237 if (rt) { 1238 if (ip6_hold_safe(net, &rt)) 1239 dst_use_noref(&rt->dst, jiffies); 1240 } else { 1241 do_create: 1242 rt = ip6_create_rt_rcu(&res); 1243 } 1244 1245 out: 1246 trace_fib6_table_lookup(net, &res, table, fl6); 1247 1248 rcu_read_unlock(); 1249 1250 return rt; 1251 } 1252 1253 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6, 1254 const struct sk_buff *skb, int flags) 1255 { 1256 return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_lookup); 1257 } 1258 EXPORT_SYMBOL_GPL(ip6_route_lookup); 1259 1260 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr, 1261 const struct in6_addr *saddr, int oif, 1262 const struct sk_buff *skb, int strict) 1263 { 1264 struct flowi6 fl6 = { 1265 .flowi6_oif = oif, 1266 .daddr = *daddr, 1267 }; 1268 struct dst_entry *dst; 1269 int flags = strict ? RT6_LOOKUP_F_IFACE : 0; 1270 1271 if (saddr) { 1272 memcpy(&fl6.saddr, saddr, sizeof(*saddr)); 1273 flags |= RT6_LOOKUP_F_HAS_SADDR; 1274 } 1275 1276 dst = fib6_rule_lookup(net, &fl6, skb, flags, ip6_pol_route_lookup); 1277 if (dst->error == 0) 1278 return (struct rt6_info *) dst; 1279 1280 dst_release(dst); 1281 1282 return NULL; 1283 } 1284 EXPORT_SYMBOL(rt6_lookup); 1285 1286 /* ip6_ins_rt is called with FREE table->tb6_lock. 1287 * It takes new route entry, the addition fails by any reason the 1288 * route is released. 1289 * Caller must hold dst before calling it. 1290 */ 1291 1292 static int __ip6_ins_rt(struct fib6_info *rt, struct nl_info *info, 1293 struct netlink_ext_ack *extack) 1294 { 1295 int err; 1296 struct fib6_table *table; 1297 1298 table = rt->fib6_table; 1299 spin_lock_bh(&table->tb6_lock); 1300 err = fib6_add(&table->tb6_root, rt, info, extack); 1301 spin_unlock_bh(&table->tb6_lock); 1302 1303 return err; 1304 } 1305 1306 int ip6_ins_rt(struct net *net, struct fib6_info *rt) 1307 { 1308 struct nl_info info = { .nl_net = net, }; 1309 1310 return __ip6_ins_rt(rt, &info, NULL); 1311 } 1312 1313 static struct rt6_info *ip6_rt_cache_alloc(const struct fib6_result *res, 1314 const struct in6_addr *daddr, 1315 const struct in6_addr *saddr) 1316 { 1317 struct fib6_info *f6i = res->f6i; 1318 struct net_device *dev; 1319 struct rt6_info *rt; 1320 1321 /* 1322 * Clone the route. 1323 */ 1324 1325 if (!fib6_info_hold_safe(f6i)) 1326 return NULL; 1327 1328 dev = ip6_rt_get_dev_rcu(res); 1329 rt = ip6_dst_alloc(dev_net(dev), dev, 0); 1330 if (!rt) { 1331 fib6_info_release(f6i); 1332 return NULL; 1333 } 1334 1335 ip6_rt_copy_init(rt, res); 1336 rt->rt6i_flags |= RTF_CACHE; 1337 rt->rt6i_dst.addr = *daddr; 1338 rt->rt6i_dst.plen = 128; 1339 1340 if (!rt6_is_gw_or_nonexthop(res)) { 1341 if (f6i->fib6_dst.plen != 128 && 1342 ipv6_addr_equal(&f6i->fib6_dst.addr, daddr)) 1343 rt->rt6i_flags |= RTF_ANYCAST; 1344 #ifdef CONFIG_IPV6_SUBTREES 1345 if (rt->rt6i_src.plen && saddr) { 1346 rt->rt6i_src.addr = *saddr; 1347 rt->rt6i_src.plen = 128; 1348 } 1349 #endif 1350 } 1351 1352 return rt; 1353 } 1354 1355 static struct rt6_info *ip6_rt_pcpu_alloc(const struct fib6_result *res) 1356 { 1357 struct fib6_info *f6i = res->f6i; 1358 unsigned short flags = fib6_info_dst_flags(f6i); 1359 struct net_device *dev; 1360 struct rt6_info *pcpu_rt; 1361 1362 if (!fib6_info_hold_safe(f6i)) 1363 return NULL; 1364 1365 rcu_read_lock(); 1366 dev = ip6_rt_get_dev_rcu(res); 1367 pcpu_rt = ip6_dst_alloc(dev_net(dev), dev, flags | DST_NOCOUNT); 1368 rcu_read_unlock(); 1369 if (!pcpu_rt) { 1370 fib6_info_release(f6i); 1371 return NULL; 1372 } 1373 ip6_rt_copy_init(pcpu_rt, res); 1374 pcpu_rt->rt6i_flags |= RTF_PCPU; 1375 1376 if (f6i->nh) 1377 pcpu_rt->sernum = rt_genid_ipv6(dev_net(dev)); 1378 1379 return pcpu_rt; 1380 } 1381 1382 static bool rt6_is_valid(const struct rt6_info *rt6) 1383 { 1384 return rt6->sernum == rt_genid_ipv6(dev_net(rt6->dst.dev)); 1385 } 1386 1387 /* It should be called with rcu_read_lock() acquired */ 1388 static struct rt6_info *rt6_get_pcpu_route(const struct fib6_result *res) 1389 { 1390 struct rt6_info *pcpu_rt; 1391 1392 pcpu_rt = this_cpu_read(*res->nh->rt6i_pcpu); 1393 1394 if (pcpu_rt && pcpu_rt->sernum && !rt6_is_valid(pcpu_rt)) { 1395 struct rt6_info *prev, **p; 1396 1397 p = this_cpu_ptr(res->nh->rt6i_pcpu); 1398 prev = xchg(p, NULL); 1399 if (prev) { 1400 dst_dev_put(&prev->dst); 1401 dst_release(&prev->dst); 1402 } 1403 1404 pcpu_rt = NULL; 1405 } 1406 1407 return pcpu_rt; 1408 } 1409 1410 static struct rt6_info *rt6_make_pcpu_route(struct net *net, 1411 const struct fib6_result *res) 1412 { 1413 struct rt6_info *pcpu_rt, *prev, **p; 1414 1415 pcpu_rt = ip6_rt_pcpu_alloc(res); 1416 if (!pcpu_rt) 1417 return NULL; 1418 1419 p = this_cpu_ptr(res->nh->rt6i_pcpu); 1420 prev = cmpxchg(p, NULL, pcpu_rt); 1421 BUG_ON(prev); 1422 1423 if (res->f6i->fib6_destroying) { 1424 struct fib6_info *from; 1425 1426 from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL); 1427 fib6_info_release(from); 1428 } 1429 1430 return pcpu_rt; 1431 } 1432 1433 /* exception hash table implementation 1434 */ 1435 static DEFINE_SPINLOCK(rt6_exception_lock); 1436 1437 /* Remove rt6_ex from hash table and free the memory 1438 * Caller must hold rt6_exception_lock 1439 */ 1440 static void rt6_remove_exception(struct rt6_exception_bucket *bucket, 1441 struct rt6_exception *rt6_ex) 1442 { 1443 struct fib6_info *from; 1444 struct net *net; 1445 1446 if (!bucket || !rt6_ex) 1447 return; 1448 1449 net = dev_net(rt6_ex->rt6i->dst.dev); 1450 net->ipv6.rt6_stats->fib_rt_cache--; 1451 1452 /* purge completely the exception to allow releasing the held resources: 1453 * some [sk] cache may keep the dst around for unlimited time 1454 */ 1455 from = xchg((__force struct fib6_info **)&rt6_ex->rt6i->from, NULL); 1456 fib6_info_release(from); 1457 dst_dev_put(&rt6_ex->rt6i->dst); 1458 1459 hlist_del_rcu(&rt6_ex->hlist); 1460 dst_release(&rt6_ex->rt6i->dst); 1461 kfree_rcu(rt6_ex, rcu); 1462 WARN_ON_ONCE(!bucket->depth); 1463 bucket->depth--; 1464 } 1465 1466 /* Remove oldest rt6_ex in bucket and free the memory 1467 * Caller must hold rt6_exception_lock 1468 */ 1469 static void rt6_exception_remove_oldest(struct rt6_exception_bucket *bucket) 1470 { 1471 struct rt6_exception *rt6_ex, *oldest = NULL; 1472 1473 if (!bucket) 1474 return; 1475 1476 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) { 1477 if (!oldest || time_before(rt6_ex->stamp, oldest->stamp)) 1478 oldest = rt6_ex; 1479 } 1480 rt6_remove_exception(bucket, oldest); 1481 } 1482 1483 static u32 rt6_exception_hash(const struct in6_addr *dst, 1484 const struct in6_addr *src) 1485 { 1486 static siphash_aligned_key_t rt6_exception_key; 1487 struct { 1488 struct in6_addr dst; 1489 struct in6_addr src; 1490 } __aligned(SIPHASH_ALIGNMENT) combined = { 1491 .dst = *dst, 1492 }; 1493 u64 val; 1494 1495 net_get_random_once(&rt6_exception_key, sizeof(rt6_exception_key)); 1496 1497 #ifdef CONFIG_IPV6_SUBTREES 1498 if (src) 1499 combined.src = *src; 1500 #endif 1501 val = siphash(&combined, sizeof(combined), &rt6_exception_key); 1502 1503 return hash_64(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT); 1504 } 1505 1506 /* Helper function to find the cached rt in the hash table 1507 * and update bucket pointer to point to the bucket for this 1508 * (daddr, saddr) pair 1509 * Caller must hold rt6_exception_lock 1510 */ 1511 static struct rt6_exception * 1512 __rt6_find_exception_spinlock(struct rt6_exception_bucket **bucket, 1513 const struct in6_addr *daddr, 1514 const struct in6_addr *saddr) 1515 { 1516 struct rt6_exception *rt6_ex; 1517 u32 hval; 1518 1519 if (!(*bucket) || !daddr) 1520 return NULL; 1521 1522 hval = rt6_exception_hash(daddr, saddr); 1523 *bucket += hval; 1524 1525 hlist_for_each_entry(rt6_ex, &(*bucket)->chain, hlist) { 1526 struct rt6_info *rt6 = rt6_ex->rt6i; 1527 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr); 1528 1529 #ifdef CONFIG_IPV6_SUBTREES 1530 if (matched && saddr) 1531 matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr); 1532 #endif 1533 if (matched) 1534 return rt6_ex; 1535 } 1536 return NULL; 1537 } 1538 1539 /* Helper function to find the cached rt in the hash table 1540 * and update bucket pointer to point to the bucket for this 1541 * (daddr, saddr) pair 1542 * Caller must hold rcu_read_lock() 1543 */ 1544 static struct rt6_exception * 1545 __rt6_find_exception_rcu(struct rt6_exception_bucket **bucket, 1546 const struct in6_addr *daddr, 1547 const struct in6_addr *saddr) 1548 { 1549 struct rt6_exception *rt6_ex; 1550 u32 hval; 1551 1552 WARN_ON_ONCE(!rcu_read_lock_held()); 1553 1554 if (!(*bucket) || !daddr) 1555 return NULL; 1556 1557 hval = rt6_exception_hash(daddr, saddr); 1558 *bucket += hval; 1559 1560 hlist_for_each_entry_rcu(rt6_ex, &(*bucket)->chain, hlist) { 1561 struct rt6_info *rt6 = rt6_ex->rt6i; 1562 bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr); 1563 1564 #ifdef CONFIG_IPV6_SUBTREES 1565 if (matched && saddr) 1566 matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr); 1567 #endif 1568 if (matched) 1569 return rt6_ex; 1570 } 1571 return NULL; 1572 } 1573 1574 static unsigned int fib6_mtu(const struct fib6_result *res) 1575 { 1576 const struct fib6_nh *nh = res->nh; 1577 unsigned int mtu; 1578 1579 if (res->f6i->fib6_pmtu) { 1580 mtu = res->f6i->fib6_pmtu; 1581 } else { 1582 struct net_device *dev = nh->fib_nh_dev; 1583 struct inet6_dev *idev; 1584 1585 rcu_read_lock(); 1586 idev = __in6_dev_get(dev); 1587 mtu = idev->cnf.mtu6; 1588 rcu_read_unlock(); 1589 } 1590 1591 mtu = min_t(unsigned int, mtu, IP6_MAX_MTU); 1592 1593 return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu); 1594 } 1595 1596 #define FIB6_EXCEPTION_BUCKET_FLUSHED 0x1UL 1597 1598 /* used when the flushed bit is not relevant, only access to the bucket 1599 * (ie., all bucket users except rt6_insert_exception); 1600 * 1601 * called under rcu lock; sometimes called with rt6_exception_lock held 1602 */ 1603 static 1604 struct rt6_exception_bucket *fib6_nh_get_excptn_bucket(const struct fib6_nh *nh, 1605 spinlock_t *lock) 1606 { 1607 struct rt6_exception_bucket *bucket; 1608 1609 if (lock) 1610 bucket = rcu_dereference_protected(nh->rt6i_exception_bucket, 1611 lockdep_is_held(lock)); 1612 else 1613 bucket = rcu_dereference(nh->rt6i_exception_bucket); 1614 1615 /* remove bucket flushed bit if set */ 1616 if (bucket) { 1617 unsigned long p = (unsigned long)bucket; 1618 1619 p &= ~FIB6_EXCEPTION_BUCKET_FLUSHED; 1620 bucket = (struct rt6_exception_bucket *)p; 1621 } 1622 1623 return bucket; 1624 } 1625 1626 static bool fib6_nh_excptn_bucket_flushed(struct rt6_exception_bucket *bucket) 1627 { 1628 unsigned long p = (unsigned long)bucket; 1629 1630 return !!(p & FIB6_EXCEPTION_BUCKET_FLUSHED); 1631 } 1632 1633 /* called with rt6_exception_lock held */ 1634 static void fib6_nh_excptn_bucket_set_flushed(struct fib6_nh *nh, 1635 spinlock_t *lock) 1636 { 1637 struct rt6_exception_bucket *bucket; 1638 unsigned long p; 1639 1640 bucket = rcu_dereference_protected(nh->rt6i_exception_bucket, 1641 lockdep_is_held(lock)); 1642 1643 p = (unsigned long)bucket; 1644 p |= FIB6_EXCEPTION_BUCKET_FLUSHED; 1645 bucket = (struct rt6_exception_bucket *)p; 1646 rcu_assign_pointer(nh->rt6i_exception_bucket, bucket); 1647 } 1648 1649 static int rt6_insert_exception(struct rt6_info *nrt, 1650 const struct fib6_result *res) 1651 { 1652 struct net *net = dev_net(nrt->dst.dev); 1653 struct rt6_exception_bucket *bucket; 1654 struct fib6_info *f6i = res->f6i; 1655 struct in6_addr *src_key = NULL; 1656 struct rt6_exception *rt6_ex; 1657 struct fib6_nh *nh = res->nh; 1658 int max_depth; 1659 int err = 0; 1660 1661 spin_lock_bh(&rt6_exception_lock); 1662 1663 bucket = rcu_dereference_protected(nh->rt6i_exception_bucket, 1664 lockdep_is_held(&rt6_exception_lock)); 1665 if (!bucket) { 1666 bucket = kcalloc(FIB6_EXCEPTION_BUCKET_SIZE, sizeof(*bucket), 1667 GFP_ATOMIC); 1668 if (!bucket) { 1669 err = -ENOMEM; 1670 goto out; 1671 } 1672 rcu_assign_pointer(nh->rt6i_exception_bucket, bucket); 1673 } else if (fib6_nh_excptn_bucket_flushed(bucket)) { 1674 err = -EINVAL; 1675 goto out; 1676 } 1677 1678 #ifdef CONFIG_IPV6_SUBTREES 1679 /* fib6_src.plen != 0 indicates f6i is in subtree 1680 * and exception table is indexed by a hash of 1681 * both fib6_dst and fib6_src. 1682 * Otherwise, the exception table is indexed by 1683 * a hash of only fib6_dst. 1684 */ 1685 if (f6i->fib6_src.plen) 1686 src_key = &nrt->rt6i_src.addr; 1687 #endif 1688 /* rt6_mtu_change() might lower mtu on f6i. 1689 * Only insert this exception route if its mtu 1690 * is less than f6i's mtu value. 1691 */ 1692 if (dst_metric_raw(&nrt->dst, RTAX_MTU) >= fib6_mtu(res)) { 1693 err = -EINVAL; 1694 goto out; 1695 } 1696 1697 rt6_ex = __rt6_find_exception_spinlock(&bucket, &nrt->rt6i_dst.addr, 1698 src_key); 1699 if (rt6_ex) 1700 rt6_remove_exception(bucket, rt6_ex); 1701 1702 rt6_ex = kzalloc(sizeof(*rt6_ex), GFP_ATOMIC); 1703 if (!rt6_ex) { 1704 err = -ENOMEM; 1705 goto out; 1706 } 1707 rt6_ex->rt6i = nrt; 1708 rt6_ex->stamp = jiffies; 1709 hlist_add_head_rcu(&rt6_ex->hlist, &bucket->chain); 1710 bucket->depth++; 1711 net->ipv6.rt6_stats->fib_rt_cache++; 1712 1713 /* Randomize max depth to avoid some side channels attacks. */ 1714 max_depth = FIB6_MAX_DEPTH + get_random_u32_below(FIB6_MAX_DEPTH); 1715 while (bucket->depth > max_depth) 1716 rt6_exception_remove_oldest(bucket); 1717 1718 out: 1719 spin_unlock_bh(&rt6_exception_lock); 1720 1721 /* Update fn->fn_sernum to invalidate all cached dst */ 1722 if (!err) { 1723 spin_lock_bh(&f6i->fib6_table->tb6_lock); 1724 fib6_update_sernum(net, f6i); 1725 spin_unlock_bh(&f6i->fib6_table->tb6_lock); 1726 fib6_force_start_gc(net); 1727 } 1728 1729 return err; 1730 } 1731 1732 static void fib6_nh_flush_exceptions(struct fib6_nh *nh, struct fib6_info *from) 1733 { 1734 struct rt6_exception_bucket *bucket; 1735 struct rt6_exception *rt6_ex; 1736 struct hlist_node *tmp; 1737 int i; 1738 1739 spin_lock_bh(&rt6_exception_lock); 1740 1741 bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock); 1742 if (!bucket) 1743 goto out; 1744 1745 /* Prevent rt6_insert_exception() to recreate the bucket list */ 1746 if (!from) 1747 fib6_nh_excptn_bucket_set_flushed(nh, &rt6_exception_lock); 1748 1749 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) { 1750 hlist_for_each_entry_safe(rt6_ex, tmp, &bucket->chain, hlist) { 1751 if (!from || 1752 rcu_access_pointer(rt6_ex->rt6i->from) == from) 1753 rt6_remove_exception(bucket, rt6_ex); 1754 } 1755 WARN_ON_ONCE(!from && bucket->depth); 1756 bucket++; 1757 } 1758 out: 1759 spin_unlock_bh(&rt6_exception_lock); 1760 } 1761 1762 static int rt6_nh_flush_exceptions(struct fib6_nh *nh, void *arg) 1763 { 1764 struct fib6_info *f6i = arg; 1765 1766 fib6_nh_flush_exceptions(nh, f6i); 1767 1768 return 0; 1769 } 1770 1771 void rt6_flush_exceptions(struct fib6_info *f6i) 1772 { 1773 if (f6i->nh) 1774 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_flush_exceptions, 1775 f6i); 1776 else 1777 fib6_nh_flush_exceptions(f6i->fib6_nh, f6i); 1778 } 1779 1780 /* Find cached rt in the hash table inside passed in rt 1781 * Caller has to hold rcu_read_lock() 1782 */ 1783 static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res, 1784 const struct in6_addr *daddr, 1785 const struct in6_addr *saddr) 1786 { 1787 const struct in6_addr *src_key = NULL; 1788 struct rt6_exception_bucket *bucket; 1789 struct rt6_exception *rt6_ex; 1790 struct rt6_info *ret = NULL; 1791 1792 #ifdef CONFIG_IPV6_SUBTREES 1793 /* fib6i_src.plen != 0 indicates f6i is in subtree 1794 * and exception table is indexed by a hash of 1795 * both fib6_dst and fib6_src. 1796 * However, the src addr used to create the hash 1797 * might not be exactly the passed in saddr which 1798 * is a /128 addr from the flow. 1799 * So we need to use f6i->fib6_src to redo lookup 1800 * if the passed in saddr does not find anything. 1801 * (See the logic in ip6_rt_cache_alloc() on how 1802 * rt->rt6i_src is updated.) 1803 */ 1804 if (res->f6i->fib6_src.plen) 1805 src_key = saddr; 1806 find_ex: 1807 #endif 1808 bucket = fib6_nh_get_excptn_bucket(res->nh, NULL); 1809 rt6_ex = __rt6_find_exception_rcu(&bucket, daddr, src_key); 1810 1811 if (rt6_ex && !rt6_check_expired(rt6_ex->rt6i)) 1812 ret = rt6_ex->rt6i; 1813 1814 #ifdef CONFIG_IPV6_SUBTREES 1815 /* Use fib6_src as src_key and redo lookup */ 1816 if (!ret && src_key && src_key != &res->f6i->fib6_src.addr) { 1817 src_key = &res->f6i->fib6_src.addr; 1818 goto find_ex; 1819 } 1820 #endif 1821 1822 return ret; 1823 } 1824 1825 /* Remove the passed in cached rt from the hash table that contains it */ 1826 static int fib6_nh_remove_exception(const struct fib6_nh *nh, int plen, 1827 const struct rt6_info *rt) 1828 { 1829 const struct in6_addr *src_key = NULL; 1830 struct rt6_exception_bucket *bucket; 1831 struct rt6_exception *rt6_ex; 1832 int err; 1833 1834 if (!rcu_access_pointer(nh->rt6i_exception_bucket)) 1835 return -ENOENT; 1836 1837 spin_lock_bh(&rt6_exception_lock); 1838 bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock); 1839 1840 #ifdef CONFIG_IPV6_SUBTREES 1841 /* rt6i_src.plen != 0 indicates 'from' is in subtree 1842 * and exception table is indexed by a hash of 1843 * both rt6i_dst and rt6i_src. 1844 * Otherwise, the exception table is indexed by 1845 * a hash of only rt6i_dst. 1846 */ 1847 if (plen) 1848 src_key = &rt->rt6i_src.addr; 1849 #endif 1850 rt6_ex = __rt6_find_exception_spinlock(&bucket, 1851 &rt->rt6i_dst.addr, 1852 src_key); 1853 if (rt6_ex) { 1854 rt6_remove_exception(bucket, rt6_ex); 1855 err = 0; 1856 } else { 1857 err = -ENOENT; 1858 } 1859 1860 spin_unlock_bh(&rt6_exception_lock); 1861 return err; 1862 } 1863 1864 struct fib6_nh_excptn_arg { 1865 struct rt6_info *rt; 1866 int plen; 1867 }; 1868 1869 static int rt6_nh_remove_exception_rt(struct fib6_nh *nh, void *_arg) 1870 { 1871 struct fib6_nh_excptn_arg *arg = _arg; 1872 int err; 1873 1874 err = fib6_nh_remove_exception(nh, arg->plen, arg->rt); 1875 if (err == 0) 1876 return 1; 1877 1878 return 0; 1879 } 1880 1881 static int rt6_remove_exception_rt(struct rt6_info *rt) 1882 { 1883 struct fib6_info *from; 1884 1885 from = rcu_dereference(rt->from); 1886 if (!from || !(rt->rt6i_flags & RTF_CACHE)) 1887 return -EINVAL; 1888 1889 if (from->nh) { 1890 struct fib6_nh_excptn_arg arg = { 1891 .rt = rt, 1892 .plen = from->fib6_src.plen 1893 }; 1894 int rc; 1895 1896 /* rc = 1 means an entry was found */ 1897 rc = nexthop_for_each_fib6_nh(from->nh, 1898 rt6_nh_remove_exception_rt, 1899 &arg); 1900 return rc ? 0 : -ENOENT; 1901 } 1902 1903 return fib6_nh_remove_exception(from->fib6_nh, 1904 from->fib6_src.plen, rt); 1905 } 1906 1907 /* Find rt6_ex which contains the passed in rt cache and 1908 * refresh its stamp 1909 */ 1910 static void fib6_nh_update_exception(const struct fib6_nh *nh, int plen, 1911 const struct rt6_info *rt) 1912 { 1913 const struct in6_addr *src_key = NULL; 1914 struct rt6_exception_bucket *bucket; 1915 struct rt6_exception *rt6_ex; 1916 1917 bucket = fib6_nh_get_excptn_bucket(nh, NULL); 1918 #ifdef CONFIG_IPV6_SUBTREES 1919 /* rt6i_src.plen != 0 indicates 'from' is in subtree 1920 * and exception table is indexed by a hash of 1921 * both rt6i_dst and rt6i_src. 1922 * Otherwise, the exception table is indexed by 1923 * a hash of only rt6i_dst. 1924 */ 1925 if (plen) 1926 src_key = &rt->rt6i_src.addr; 1927 #endif 1928 rt6_ex = __rt6_find_exception_rcu(&bucket, &rt->rt6i_dst.addr, src_key); 1929 if (rt6_ex) 1930 rt6_ex->stamp = jiffies; 1931 } 1932 1933 struct fib6_nh_match_arg { 1934 const struct net_device *dev; 1935 const struct in6_addr *gw; 1936 struct fib6_nh *match; 1937 }; 1938 1939 /* determine if fib6_nh has given device and gateway */ 1940 static int fib6_nh_find_match(struct fib6_nh *nh, void *_arg) 1941 { 1942 struct fib6_nh_match_arg *arg = _arg; 1943 1944 if (arg->dev != nh->fib_nh_dev || 1945 (arg->gw && !nh->fib_nh_gw_family) || 1946 (!arg->gw && nh->fib_nh_gw_family) || 1947 (arg->gw && !ipv6_addr_equal(arg->gw, &nh->fib_nh_gw6))) 1948 return 0; 1949 1950 arg->match = nh; 1951 1952 /* found a match, break the loop */ 1953 return 1; 1954 } 1955 1956 static void rt6_update_exception_stamp_rt(struct rt6_info *rt) 1957 { 1958 struct fib6_info *from; 1959 struct fib6_nh *fib6_nh; 1960 1961 rcu_read_lock(); 1962 1963 from = rcu_dereference(rt->from); 1964 if (!from || !(rt->rt6i_flags & RTF_CACHE)) 1965 goto unlock; 1966 1967 if (from->nh) { 1968 struct fib6_nh_match_arg arg = { 1969 .dev = rt->dst.dev, 1970 .gw = &rt->rt6i_gateway, 1971 }; 1972 1973 nexthop_for_each_fib6_nh(from->nh, fib6_nh_find_match, &arg); 1974 1975 if (!arg.match) 1976 goto unlock; 1977 fib6_nh = arg.match; 1978 } else { 1979 fib6_nh = from->fib6_nh; 1980 } 1981 fib6_nh_update_exception(fib6_nh, from->fib6_src.plen, rt); 1982 unlock: 1983 rcu_read_unlock(); 1984 } 1985 1986 static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev, 1987 struct rt6_info *rt, int mtu) 1988 { 1989 /* If the new MTU is lower than the route PMTU, this new MTU will be the 1990 * lowest MTU in the path: always allow updating the route PMTU to 1991 * reflect PMTU decreases. 1992 * 1993 * If the new MTU is higher, and the route PMTU is equal to the local 1994 * MTU, this means the old MTU is the lowest in the path, so allow 1995 * updating it: if other nodes now have lower MTUs, PMTU discovery will 1996 * handle this. 1997 */ 1998 1999 if (dst_mtu(&rt->dst) >= mtu) 2000 return true; 2001 2002 if (dst_mtu(&rt->dst) == idev->cnf.mtu6) 2003 return true; 2004 2005 return false; 2006 } 2007 2008 static void rt6_exceptions_update_pmtu(struct inet6_dev *idev, 2009 const struct fib6_nh *nh, int mtu) 2010 { 2011 struct rt6_exception_bucket *bucket; 2012 struct rt6_exception *rt6_ex; 2013 int i; 2014 2015 bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock); 2016 if (!bucket) 2017 return; 2018 2019 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) { 2020 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) { 2021 struct rt6_info *entry = rt6_ex->rt6i; 2022 2023 /* For RTF_CACHE with rt6i_pmtu == 0 (i.e. a redirected 2024 * route), the metrics of its rt->from have already 2025 * been updated. 2026 */ 2027 if (dst_metric_raw(&entry->dst, RTAX_MTU) && 2028 rt6_mtu_change_route_allowed(idev, entry, mtu)) 2029 dst_metric_set(&entry->dst, RTAX_MTU, mtu); 2030 } 2031 bucket++; 2032 } 2033 } 2034 2035 #define RTF_CACHE_GATEWAY (RTF_GATEWAY | RTF_CACHE) 2036 2037 static void fib6_nh_exceptions_clean_tohost(const struct fib6_nh *nh, 2038 const struct in6_addr *gateway) 2039 { 2040 struct rt6_exception_bucket *bucket; 2041 struct rt6_exception *rt6_ex; 2042 struct hlist_node *tmp; 2043 int i; 2044 2045 if (!rcu_access_pointer(nh->rt6i_exception_bucket)) 2046 return; 2047 2048 spin_lock_bh(&rt6_exception_lock); 2049 bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock); 2050 if (bucket) { 2051 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) { 2052 hlist_for_each_entry_safe(rt6_ex, tmp, 2053 &bucket->chain, hlist) { 2054 struct rt6_info *entry = rt6_ex->rt6i; 2055 2056 if ((entry->rt6i_flags & RTF_CACHE_GATEWAY) == 2057 RTF_CACHE_GATEWAY && 2058 ipv6_addr_equal(gateway, 2059 &entry->rt6i_gateway)) { 2060 rt6_remove_exception(bucket, rt6_ex); 2061 } 2062 } 2063 bucket++; 2064 } 2065 } 2066 2067 spin_unlock_bh(&rt6_exception_lock); 2068 } 2069 2070 static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket, 2071 struct rt6_exception *rt6_ex, 2072 struct fib6_gc_args *gc_args, 2073 unsigned long now) 2074 { 2075 struct rt6_info *rt = rt6_ex->rt6i; 2076 2077 /* we are pruning and obsoleting aged-out and non gateway exceptions 2078 * even if others have still references to them, so that on next 2079 * dst_check() such references can be dropped. 2080 * EXPIRES exceptions - e.g. pmtu-generated ones are pruned when 2081 * expired, independently from their aging, as per RFC 8201 section 4 2082 */ 2083 if (!(rt->rt6i_flags & RTF_EXPIRES)) { 2084 if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) { 2085 RT6_TRACE("aging clone %p\n", rt); 2086 rt6_remove_exception(bucket, rt6_ex); 2087 return; 2088 } 2089 } else if (time_after(jiffies, rt->dst.expires)) { 2090 RT6_TRACE("purging expired route %p\n", rt); 2091 rt6_remove_exception(bucket, rt6_ex); 2092 return; 2093 } 2094 2095 if (rt->rt6i_flags & RTF_GATEWAY) { 2096 struct neighbour *neigh; 2097 2098 neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway); 2099 2100 if (!(neigh && (neigh->flags & NTF_ROUTER))) { 2101 RT6_TRACE("purging route %p via non-router but gateway\n", 2102 rt); 2103 rt6_remove_exception(bucket, rt6_ex); 2104 return; 2105 } 2106 } 2107 2108 gc_args->more++; 2109 } 2110 2111 static void fib6_nh_age_exceptions(const struct fib6_nh *nh, 2112 struct fib6_gc_args *gc_args, 2113 unsigned long now) 2114 { 2115 struct rt6_exception_bucket *bucket; 2116 struct rt6_exception *rt6_ex; 2117 struct hlist_node *tmp; 2118 int i; 2119 2120 if (!rcu_access_pointer(nh->rt6i_exception_bucket)) 2121 return; 2122 2123 rcu_read_lock_bh(); 2124 spin_lock(&rt6_exception_lock); 2125 bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock); 2126 if (bucket) { 2127 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) { 2128 hlist_for_each_entry_safe(rt6_ex, tmp, 2129 &bucket->chain, hlist) { 2130 rt6_age_examine_exception(bucket, rt6_ex, 2131 gc_args, now); 2132 } 2133 bucket++; 2134 } 2135 } 2136 spin_unlock(&rt6_exception_lock); 2137 rcu_read_unlock_bh(); 2138 } 2139 2140 struct fib6_nh_age_excptn_arg { 2141 struct fib6_gc_args *gc_args; 2142 unsigned long now; 2143 }; 2144 2145 static int rt6_nh_age_exceptions(struct fib6_nh *nh, void *_arg) 2146 { 2147 struct fib6_nh_age_excptn_arg *arg = _arg; 2148 2149 fib6_nh_age_exceptions(nh, arg->gc_args, arg->now); 2150 return 0; 2151 } 2152 2153 void rt6_age_exceptions(struct fib6_info *f6i, 2154 struct fib6_gc_args *gc_args, 2155 unsigned long now) 2156 { 2157 if (f6i->nh) { 2158 struct fib6_nh_age_excptn_arg arg = { 2159 .gc_args = gc_args, 2160 .now = now 2161 }; 2162 2163 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_age_exceptions, 2164 &arg); 2165 } else { 2166 fib6_nh_age_exceptions(f6i->fib6_nh, gc_args, now); 2167 } 2168 } 2169 2170 /* must be called with rcu lock held */ 2171 int fib6_table_lookup(struct net *net, struct fib6_table *table, int oif, 2172 struct flowi6 *fl6, struct fib6_result *res, int strict) 2173 { 2174 struct fib6_node *fn, *saved_fn; 2175 2176 fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); 2177 saved_fn = fn; 2178 2179 redo_rt6_select: 2180 rt6_select(net, fn, oif, res, strict); 2181 if (res->f6i == net->ipv6.fib6_null_entry) { 2182 fn = fib6_backtrack(fn, &fl6->saddr); 2183 if (fn) 2184 goto redo_rt6_select; 2185 else if (strict & RT6_LOOKUP_F_REACHABLE) { 2186 /* also consider unreachable route */ 2187 strict &= ~RT6_LOOKUP_F_REACHABLE; 2188 fn = saved_fn; 2189 goto redo_rt6_select; 2190 } 2191 } 2192 2193 trace_fib6_table_lookup(net, res, table, fl6); 2194 2195 return 0; 2196 } 2197 2198 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, 2199 int oif, struct flowi6 *fl6, 2200 const struct sk_buff *skb, int flags) 2201 { 2202 struct fib6_result res = {}; 2203 struct rt6_info *rt = NULL; 2204 int strict = 0; 2205 2206 WARN_ON_ONCE((flags & RT6_LOOKUP_F_DST_NOREF) && 2207 !rcu_read_lock_held()); 2208 2209 strict |= flags & RT6_LOOKUP_F_IFACE; 2210 strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE; 2211 if (net->ipv6.devconf_all->forwarding == 0) 2212 strict |= RT6_LOOKUP_F_REACHABLE; 2213 2214 rcu_read_lock(); 2215 2216 fib6_table_lookup(net, table, oif, fl6, &res, strict); 2217 if (res.f6i == net->ipv6.fib6_null_entry) 2218 goto out; 2219 2220 fib6_select_path(net, &res, fl6, oif, false, skb, strict); 2221 2222 /*Search through exception table */ 2223 rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr); 2224 if (rt) { 2225 goto out; 2226 } else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) && 2227 !res.nh->fib_nh_gw_family)) { 2228 /* Create a RTF_CACHE clone which will not be 2229 * owned by the fib6 tree. It is for the special case where 2230 * the daddr in the skb during the neighbor look-up is different 2231 * from the fl6->daddr used to look-up route here. 2232 */ 2233 rt = ip6_rt_cache_alloc(&res, &fl6->daddr, NULL); 2234 2235 if (rt) { 2236 /* 1 refcnt is taken during ip6_rt_cache_alloc(). 2237 * As rt6_uncached_list_add() does not consume refcnt, 2238 * this refcnt is always returned to the caller even 2239 * if caller sets RT6_LOOKUP_F_DST_NOREF flag. 2240 */ 2241 rt6_uncached_list_add(rt); 2242 rcu_read_unlock(); 2243 2244 return rt; 2245 } 2246 } else { 2247 /* Get a percpu copy */ 2248 local_bh_disable(); 2249 rt = rt6_get_pcpu_route(&res); 2250 2251 if (!rt) 2252 rt = rt6_make_pcpu_route(net, &res); 2253 2254 local_bh_enable(); 2255 } 2256 out: 2257 if (!rt) 2258 rt = net->ipv6.ip6_null_entry; 2259 if (!(flags & RT6_LOOKUP_F_DST_NOREF)) 2260 ip6_hold_safe(net, &rt); 2261 rcu_read_unlock(); 2262 2263 return rt; 2264 } 2265 EXPORT_SYMBOL_GPL(ip6_pol_route); 2266 2267 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_input(struct net *net, 2268 struct fib6_table *table, 2269 struct flowi6 *fl6, 2270 const struct sk_buff *skb, 2271 int flags) 2272 { 2273 return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, skb, flags); 2274 } 2275 2276 struct dst_entry *ip6_route_input_lookup(struct net *net, 2277 struct net_device *dev, 2278 struct flowi6 *fl6, 2279 const struct sk_buff *skb, 2280 int flags) 2281 { 2282 if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG) 2283 flags |= RT6_LOOKUP_F_IFACE; 2284 2285 return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_input); 2286 } 2287 EXPORT_SYMBOL_GPL(ip6_route_input_lookup); 2288 2289 static void ip6_multipath_l3_keys(const struct sk_buff *skb, 2290 struct flow_keys *keys, 2291 struct flow_keys *flkeys) 2292 { 2293 const struct ipv6hdr *outer_iph = ipv6_hdr(skb); 2294 const struct ipv6hdr *key_iph = outer_iph; 2295 struct flow_keys *_flkeys = flkeys; 2296 const struct ipv6hdr *inner_iph; 2297 const struct icmp6hdr *icmph; 2298 struct ipv6hdr _inner_iph; 2299 struct icmp6hdr _icmph; 2300 2301 if (likely(outer_iph->nexthdr != IPPROTO_ICMPV6)) 2302 goto out; 2303 2304 icmph = skb_header_pointer(skb, skb_transport_offset(skb), 2305 sizeof(_icmph), &_icmph); 2306 if (!icmph) 2307 goto out; 2308 2309 if (!icmpv6_is_err(icmph->icmp6_type)) 2310 goto out; 2311 2312 inner_iph = skb_header_pointer(skb, 2313 skb_transport_offset(skb) + sizeof(*icmph), 2314 sizeof(_inner_iph), &_inner_iph); 2315 if (!inner_iph) 2316 goto out; 2317 2318 key_iph = inner_iph; 2319 _flkeys = NULL; 2320 out: 2321 if (_flkeys) { 2322 keys->addrs.v6addrs.src = _flkeys->addrs.v6addrs.src; 2323 keys->addrs.v6addrs.dst = _flkeys->addrs.v6addrs.dst; 2324 keys->tags.flow_label = _flkeys->tags.flow_label; 2325 keys->basic.ip_proto = _flkeys->basic.ip_proto; 2326 } else { 2327 keys->addrs.v6addrs.src = key_iph->saddr; 2328 keys->addrs.v6addrs.dst = key_iph->daddr; 2329 keys->tags.flow_label = ip6_flowlabel(key_iph); 2330 keys->basic.ip_proto = key_iph->nexthdr; 2331 } 2332 } 2333 2334 static u32 rt6_multipath_custom_hash_outer(const struct net *net, 2335 const struct sk_buff *skb, 2336 bool *p_has_inner) 2337 { 2338 u32 hash_fields = ip6_multipath_hash_fields(net); 2339 struct flow_keys keys, hash_keys; 2340 2341 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2342 return 0; 2343 2344 memset(&hash_keys, 0, sizeof(hash_keys)); 2345 skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); 2346 2347 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2348 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2349 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2350 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2351 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2352 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2353 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2354 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL) 2355 hash_keys.tags.flow_label = keys.tags.flow_label; 2356 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 2357 hash_keys.ports.src = keys.ports.src; 2358 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2359 hash_keys.ports.dst = keys.ports.dst; 2360 2361 *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); 2362 return flow_hash_from_keys(&hash_keys); 2363 } 2364 2365 static u32 rt6_multipath_custom_hash_inner(const struct net *net, 2366 const struct sk_buff *skb, 2367 bool has_inner) 2368 { 2369 u32 hash_fields = ip6_multipath_hash_fields(net); 2370 struct flow_keys keys, hash_keys; 2371 2372 /* We assume the packet carries an encapsulation, but if none was 2373 * encountered during dissection of the outer flow, then there is no 2374 * point in calling the flow dissector again. 2375 */ 2376 if (!has_inner) 2377 return 0; 2378 2379 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) 2380 return 0; 2381 2382 memset(&hash_keys, 0, sizeof(hash_keys)); 2383 skb_flow_dissect_flow_keys(skb, &keys, 0); 2384 2385 if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) 2386 return 0; 2387 2388 if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2389 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2390 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 2391 hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; 2392 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 2393 hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; 2394 } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2395 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2396 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) 2397 hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; 2398 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) 2399 hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; 2400 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) 2401 hash_keys.tags.flow_label = keys.tags.flow_label; 2402 } 2403 2404 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) 2405 hash_keys.basic.ip_proto = keys.basic.ip_proto; 2406 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) 2407 hash_keys.ports.src = keys.ports.src; 2408 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 2409 hash_keys.ports.dst = keys.ports.dst; 2410 2411 return flow_hash_from_keys(&hash_keys); 2412 } 2413 2414 static u32 rt6_multipath_custom_hash_skb(const struct net *net, 2415 const struct sk_buff *skb) 2416 { 2417 u32 mhash, mhash_inner; 2418 bool has_inner = true; 2419 2420 mhash = rt6_multipath_custom_hash_outer(net, skb, &has_inner); 2421 mhash_inner = rt6_multipath_custom_hash_inner(net, skb, has_inner); 2422 2423 return jhash_2words(mhash, mhash_inner, 0); 2424 } 2425 2426 static u32 rt6_multipath_custom_hash_fl6(const struct net *net, 2427 const struct flowi6 *fl6) 2428 { 2429 u32 hash_fields = ip6_multipath_hash_fields(net); 2430 struct flow_keys hash_keys; 2431 2432 if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) 2433 return 0; 2434 2435 memset(&hash_keys, 0, sizeof(hash_keys)); 2436 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2437 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) 2438 hash_keys.addrs.v6addrs.src = fl6->saddr; 2439 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) 2440 hash_keys.addrs.v6addrs.dst = fl6->daddr; 2441 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 2442 hash_keys.basic.ip_proto = fl6->flowi6_proto; 2443 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL) 2444 hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6); 2445 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) 2446 hash_keys.ports.src = fl6->fl6_sport; 2447 if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) 2448 hash_keys.ports.dst = fl6->fl6_dport; 2449 2450 return flow_hash_from_keys(&hash_keys); 2451 } 2452 2453 /* if skb is set it will be used and fl6 can be NULL */ 2454 u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6, 2455 const struct sk_buff *skb, struct flow_keys *flkeys) 2456 { 2457 struct flow_keys hash_keys; 2458 u32 mhash = 0; 2459 2460 switch (ip6_multipath_hash_policy(net)) { 2461 case 0: 2462 memset(&hash_keys, 0, sizeof(hash_keys)); 2463 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2464 if (skb) { 2465 ip6_multipath_l3_keys(skb, &hash_keys, flkeys); 2466 } else { 2467 hash_keys.addrs.v6addrs.src = fl6->saddr; 2468 hash_keys.addrs.v6addrs.dst = fl6->daddr; 2469 hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6); 2470 hash_keys.basic.ip_proto = fl6->flowi6_proto; 2471 } 2472 mhash = flow_hash_from_keys(&hash_keys); 2473 break; 2474 case 1: 2475 if (skb) { 2476 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 2477 struct flow_keys keys; 2478 2479 /* short-circuit if we already have L4 hash present */ 2480 if (skb->l4_hash) 2481 return skb_get_hash_raw(skb) >> 1; 2482 2483 memset(&hash_keys, 0, sizeof(hash_keys)); 2484 2485 if (!flkeys) { 2486 skb_flow_dissect_flow_keys(skb, &keys, flag); 2487 flkeys = &keys; 2488 } 2489 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2490 hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src; 2491 hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst; 2492 hash_keys.ports.src = flkeys->ports.src; 2493 hash_keys.ports.dst = flkeys->ports.dst; 2494 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2495 } else { 2496 memset(&hash_keys, 0, sizeof(hash_keys)); 2497 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2498 hash_keys.addrs.v6addrs.src = fl6->saddr; 2499 hash_keys.addrs.v6addrs.dst = fl6->daddr; 2500 hash_keys.ports.src = fl6->fl6_sport; 2501 hash_keys.ports.dst = fl6->fl6_dport; 2502 hash_keys.basic.ip_proto = fl6->flowi6_proto; 2503 } 2504 mhash = flow_hash_from_keys(&hash_keys); 2505 break; 2506 case 2: 2507 memset(&hash_keys, 0, sizeof(hash_keys)); 2508 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2509 if (skb) { 2510 struct flow_keys keys; 2511 2512 if (!flkeys) { 2513 skb_flow_dissect_flow_keys(skb, &keys, 0); 2514 flkeys = &keys; 2515 } 2516 2517 /* Inner can be v4 or v6 */ 2518 if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { 2519 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; 2520 hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; 2521 hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; 2522 } else if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { 2523 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2524 hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src; 2525 hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst; 2526 hash_keys.tags.flow_label = flkeys->tags.flow_label; 2527 hash_keys.basic.ip_proto = flkeys->basic.ip_proto; 2528 } else { 2529 /* Same as case 0 */ 2530 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2531 ip6_multipath_l3_keys(skb, &hash_keys, flkeys); 2532 } 2533 } else { 2534 /* Same as case 0 */ 2535 hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; 2536 hash_keys.addrs.v6addrs.src = fl6->saddr; 2537 hash_keys.addrs.v6addrs.dst = fl6->daddr; 2538 hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6); 2539 hash_keys.basic.ip_proto = fl6->flowi6_proto; 2540 } 2541 mhash = flow_hash_from_keys(&hash_keys); 2542 break; 2543 case 3: 2544 if (skb) 2545 mhash = rt6_multipath_custom_hash_skb(net, skb); 2546 else 2547 mhash = rt6_multipath_custom_hash_fl6(net, fl6); 2548 break; 2549 } 2550 2551 return mhash >> 1; 2552 } 2553 2554 /* Called with rcu held */ 2555 void ip6_route_input(struct sk_buff *skb) 2556 { 2557 const struct ipv6hdr *iph = ipv6_hdr(skb); 2558 struct net *net = dev_net(skb->dev); 2559 int flags = RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_DST_NOREF; 2560 struct ip_tunnel_info *tun_info; 2561 struct flowi6 fl6 = { 2562 .flowi6_iif = skb->dev->ifindex, 2563 .daddr = iph->daddr, 2564 .saddr = iph->saddr, 2565 .flowlabel = ip6_flowinfo(iph), 2566 .flowi6_mark = skb->mark, 2567 .flowi6_proto = iph->nexthdr, 2568 }; 2569 struct flow_keys *flkeys = NULL, _flkeys; 2570 2571 tun_info = skb_tunnel_info(skb); 2572 if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) 2573 fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id; 2574 2575 if (fib6_rules_early_flow_dissect(net, skb, &fl6, &_flkeys)) 2576 flkeys = &_flkeys; 2577 2578 if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6)) 2579 fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, flkeys); 2580 skb_dst_drop(skb); 2581 skb_dst_set_noref(skb, ip6_route_input_lookup(net, skb->dev, 2582 &fl6, skb, flags)); 2583 } 2584 2585 INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_output(struct net *net, 2586 struct fib6_table *table, 2587 struct flowi6 *fl6, 2588 const struct sk_buff *skb, 2589 int flags) 2590 { 2591 return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, skb, flags); 2592 } 2593 2594 static struct dst_entry *ip6_route_output_flags_noref(struct net *net, 2595 const struct sock *sk, 2596 struct flowi6 *fl6, 2597 int flags) 2598 { 2599 bool any_src; 2600 2601 if (ipv6_addr_type(&fl6->daddr) & 2602 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)) { 2603 struct dst_entry *dst; 2604 2605 /* This function does not take refcnt on the dst */ 2606 dst = l3mdev_link_scope_lookup(net, fl6); 2607 if (dst) 2608 return dst; 2609 } 2610 2611 fl6->flowi6_iif = LOOPBACK_IFINDEX; 2612 2613 flags |= RT6_LOOKUP_F_DST_NOREF; 2614 any_src = ipv6_addr_any(&fl6->saddr); 2615 if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) || 2616 (fl6->flowi6_oif && any_src)) 2617 flags |= RT6_LOOKUP_F_IFACE; 2618 2619 if (!any_src) 2620 flags |= RT6_LOOKUP_F_HAS_SADDR; 2621 else if (sk) 2622 flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs); 2623 2624 return fib6_rule_lookup(net, fl6, NULL, flags, ip6_pol_route_output); 2625 } 2626 2627 struct dst_entry *ip6_route_output_flags(struct net *net, 2628 const struct sock *sk, 2629 struct flowi6 *fl6, 2630 int flags) 2631 { 2632 struct dst_entry *dst; 2633 struct rt6_info *rt6; 2634 2635 rcu_read_lock(); 2636 dst = ip6_route_output_flags_noref(net, sk, fl6, flags); 2637 rt6 = (struct rt6_info *)dst; 2638 /* For dst cached in uncached_list, refcnt is already taken. */ 2639 if (list_empty(&rt6->dst.rt_uncached) && !dst_hold_safe(dst)) { 2640 dst = &net->ipv6.ip6_null_entry->dst; 2641 dst_hold(dst); 2642 } 2643 rcu_read_unlock(); 2644 2645 return dst; 2646 } 2647 EXPORT_SYMBOL_GPL(ip6_route_output_flags); 2648 2649 struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig) 2650 { 2651 struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig; 2652 struct net_device *loopback_dev = net->loopback_dev; 2653 struct dst_entry *new = NULL; 2654 2655 rt = dst_alloc(&ip6_dst_blackhole_ops, loopback_dev, 1, 2656 DST_OBSOLETE_DEAD, 0); 2657 if (rt) { 2658 rt6_info_init(rt); 2659 atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc); 2660 2661 new = &rt->dst; 2662 new->__use = 1; 2663 new->input = dst_discard; 2664 new->output = dst_discard_out; 2665 2666 dst_copy_metrics(new, &ort->dst); 2667 2668 rt->rt6i_idev = in6_dev_get(loopback_dev); 2669 rt->rt6i_gateway = ort->rt6i_gateway; 2670 rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU; 2671 2672 memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key)); 2673 #ifdef CONFIG_IPV6_SUBTREES 2674 memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key)); 2675 #endif 2676 } 2677 2678 dst_release(dst_orig); 2679 return new ? new : ERR_PTR(-ENOMEM); 2680 } 2681 2682 /* 2683 * Destination cache support functions 2684 */ 2685 2686 static bool fib6_check(struct fib6_info *f6i, u32 cookie) 2687 { 2688 u32 rt_cookie = 0; 2689 2690 if (!fib6_get_cookie_safe(f6i, &rt_cookie) || rt_cookie != cookie) 2691 return false; 2692 2693 if (fib6_check_expired(f6i)) 2694 return false; 2695 2696 return true; 2697 } 2698 2699 static struct dst_entry *rt6_check(struct rt6_info *rt, 2700 struct fib6_info *from, 2701 u32 cookie) 2702 { 2703 u32 rt_cookie = 0; 2704 2705 if (!from || !fib6_get_cookie_safe(from, &rt_cookie) || 2706 rt_cookie != cookie) 2707 return NULL; 2708 2709 if (rt6_check_expired(rt)) 2710 return NULL; 2711 2712 return &rt->dst; 2713 } 2714 2715 static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt, 2716 struct fib6_info *from, 2717 u32 cookie) 2718 { 2719 if (!__rt6_check_expired(rt) && 2720 rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && 2721 fib6_check(from, cookie)) 2722 return &rt->dst; 2723 else 2724 return NULL; 2725 } 2726 2727 INDIRECT_CALLABLE_SCOPE struct dst_entry *ip6_dst_check(struct dst_entry *dst, 2728 u32 cookie) 2729 { 2730 struct dst_entry *dst_ret; 2731 struct fib6_info *from; 2732 struct rt6_info *rt; 2733 2734 rt = container_of(dst, struct rt6_info, dst); 2735 2736 if (rt->sernum) 2737 return rt6_is_valid(rt) ? dst : NULL; 2738 2739 rcu_read_lock(); 2740 2741 /* All IPV6 dsts are created with ->obsolete set to the value 2742 * DST_OBSOLETE_FORCE_CHK which forces validation calls down 2743 * into this function always. 2744 */ 2745 2746 from = rcu_dereference(rt->from); 2747 2748 if (from && (rt->rt6i_flags & RTF_PCPU || 2749 unlikely(!list_empty(&rt->dst.rt_uncached)))) 2750 dst_ret = rt6_dst_from_check(rt, from, cookie); 2751 else 2752 dst_ret = rt6_check(rt, from, cookie); 2753 2754 rcu_read_unlock(); 2755 2756 return dst_ret; 2757 } 2758 EXPORT_INDIRECT_CALLABLE(ip6_dst_check); 2759 2760 static struct dst_entry *ip6_negative_advice(struct dst_entry *dst) 2761 { 2762 struct rt6_info *rt = (struct rt6_info *) dst; 2763 2764 if (rt) { 2765 if (rt->rt6i_flags & RTF_CACHE) { 2766 rcu_read_lock(); 2767 if (rt6_check_expired(rt)) { 2768 rt6_remove_exception_rt(rt); 2769 dst = NULL; 2770 } 2771 rcu_read_unlock(); 2772 } else { 2773 dst_release(dst); 2774 dst = NULL; 2775 } 2776 } 2777 return dst; 2778 } 2779 2780 static void ip6_link_failure(struct sk_buff *skb) 2781 { 2782 struct rt6_info *rt; 2783 2784 icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0); 2785 2786 rt = (struct rt6_info *) skb_dst(skb); 2787 if (rt) { 2788 rcu_read_lock(); 2789 if (rt->rt6i_flags & RTF_CACHE) { 2790 rt6_remove_exception_rt(rt); 2791 } else { 2792 struct fib6_info *from; 2793 struct fib6_node *fn; 2794 2795 from = rcu_dereference(rt->from); 2796 if (from) { 2797 fn = rcu_dereference(from->fib6_node); 2798 if (fn && (rt->rt6i_flags & RTF_DEFAULT)) 2799 WRITE_ONCE(fn->fn_sernum, -1); 2800 } 2801 } 2802 rcu_read_unlock(); 2803 } 2804 } 2805 2806 static void rt6_update_expires(struct rt6_info *rt0, int timeout) 2807 { 2808 if (!(rt0->rt6i_flags & RTF_EXPIRES)) { 2809 struct fib6_info *from; 2810 2811 rcu_read_lock(); 2812 from = rcu_dereference(rt0->from); 2813 if (from) 2814 rt0->dst.expires = from->expires; 2815 rcu_read_unlock(); 2816 } 2817 2818 dst_set_expires(&rt0->dst, timeout); 2819 rt0->rt6i_flags |= RTF_EXPIRES; 2820 } 2821 2822 static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu) 2823 { 2824 struct net *net = dev_net(rt->dst.dev); 2825 2826 dst_metric_set(&rt->dst, RTAX_MTU, mtu); 2827 rt->rt6i_flags |= RTF_MODIFIED; 2828 rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires); 2829 } 2830 2831 static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt) 2832 { 2833 return !(rt->rt6i_flags & RTF_CACHE) && 2834 (rt->rt6i_flags & RTF_PCPU || rcu_access_pointer(rt->from)); 2835 } 2836 2837 static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk, 2838 const struct ipv6hdr *iph, u32 mtu, 2839 bool confirm_neigh) 2840 { 2841 const struct in6_addr *daddr, *saddr; 2842 struct rt6_info *rt6 = (struct rt6_info *)dst; 2843 2844 /* Note: do *NOT* check dst_metric_locked(dst, RTAX_MTU) 2845 * IPv6 pmtu discovery isn't optional, so 'mtu lock' cannot disable it. 2846 * [see also comment in rt6_mtu_change_route()] 2847 */ 2848 2849 if (iph) { 2850 daddr = &iph->daddr; 2851 saddr = &iph->saddr; 2852 } else if (sk) { 2853 daddr = &sk->sk_v6_daddr; 2854 saddr = &inet6_sk(sk)->saddr; 2855 } else { 2856 daddr = NULL; 2857 saddr = NULL; 2858 } 2859 2860 if (confirm_neigh) 2861 dst_confirm_neigh(dst, daddr); 2862 2863 if (mtu < IPV6_MIN_MTU) 2864 return; 2865 if (mtu >= dst_mtu(dst)) 2866 return; 2867 2868 if (!rt6_cache_allowed_for_pmtu(rt6)) { 2869 rt6_do_update_pmtu(rt6, mtu); 2870 /* update rt6_ex->stamp for cache */ 2871 if (rt6->rt6i_flags & RTF_CACHE) 2872 rt6_update_exception_stamp_rt(rt6); 2873 } else if (daddr) { 2874 struct fib6_result res = {}; 2875 struct rt6_info *nrt6; 2876 2877 rcu_read_lock(); 2878 res.f6i = rcu_dereference(rt6->from); 2879 if (!res.f6i) 2880 goto out_unlock; 2881 2882 res.fib6_flags = res.f6i->fib6_flags; 2883 res.fib6_type = res.f6i->fib6_type; 2884 2885 if (res.f6i->nh) { 2886 struct fib6_nh_match_arg arg = { 2887 .dev = dst->dev, 2888 .gw = &rt6->rt6i_gateway, 2889 }; 2890 2891 nexthop_for_each_fib6_nh(res.f6i->nh, 2892 fib6_nh_find_match, &arg); 2893 2894 /* fib6_info uses a nexthop that does not have fib6_nh 2895 * using the dst->dev + gw. Should be impossible. 2896 */ 2897 if (!arg.match) 2898 goto out_unlock; 2899 2900 res.nh = arg.match; 2901 } else { 2902 res.nh = res.f6i->fib6_nh; 2903 } 2904 2905 nrt6 = ip6_rt_cache_alloc(&res, daddr, saddr); 2906 if (nrt6) { 2907 rt6_do_update_pmtu(nrt6, mtu); 2908 if (rt6_insert_exception(nrt6, &res)) 2909 dst_release_immediate(&nrt6->dst); 2910 } 2911 out_unlock: 2912 rcu_read_unlock(); 2913 } 2914 } 2915 2916 static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, 2917 struct sk_buff *skb, u32 mtu, 2918 bool confirm_neigh) 2919 { 2920 __ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu, 2921 confirm_neigh); 2922 } 2923 2924 void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, 2925 int oif, u32 mark, kuid_t uid) 2926 { 2927 const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data; 2928 struct dst_entry *dst; 2929 struct flowi6 fl6 = { 2930 .flowi6_oif = oif, 2931 .flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark), 2932 .daddr = iph->daddr, 2933 .saddr = iph->saddr, 2934 .flowlabel = ip6_flowinfo(iph), 2935 .flowi6_uid = uid, 2936 }; 2937 2938 dst = ip6_route_output(net, NULL, &fl6); 2939 if (!dst->error) 2940 __ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu), true); 2941 dst_release(dst); 2942 } 2943 EXPORT_SYMBOL_GPL(ip6_update_pmtu); 2944 2945 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu) 2946 { 2947 int oif = sk->sk_bound_dev_if; 2948 struct dst_entry *dst; 2949 2950 if (!oif && skb->dev) 2951 oif = l3mdev_master_ifindex(skb->dev); 2952 2953 ip6_update_pmtu(skb, sock_net(sk), mtu, oif, READ_ONCE(sk->sk_mark), 2954 sk->sk_uid); 2955 2956 dst = __sk_dst_get(sk); 2957 if (!dst || !dst->obsolete || 2958 dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) 2959 return; 2960 2961 bh_lock_sock(sk); 2962 if (!sock_owned_by_user(sk) && !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) 2963 ip6_datagram_dst_update(sk, false); 2964 bh_unlock_sock(sk); 2965 } 2966 EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu); 2967 2968 void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst, 2969 const struct flowi6 *fl6) 2970 { 2971 #ifdef CONFIG_IPV6_SUBTREES 2972 struct ipv6_pinfo *np = inet6_sk(sk); 2973 #endif 2974 2975 ip6_dst_store(sk, dst, 2976 ipv6_addr_equal(&fl6->daddr, &sk->sk_v6_daddr) ? 2977 &sk->sk_v6_daddr : NULL, 2978 #ifdef CONFIG_IPV6_SUBTREES 2979 ipv6_addr_equal(&fl6->saddr, &np->saddr) ? 2980 &np->saddr : 2981 #endif 2982 NULL); 2983 } 2984 2985 static bool ip6_redirect_nh_match(const struct fib6_result *res, 2986 struct flowi6 *fl6, 2987 const struct in6_addr *gw, 2988 struct rt6_info **ret) 2989 { 2990 const struct fib6_nh *nh = res->nh; 2991 2992 if (nh->fib_nh_flags & RTNH_F_DEAD || !nh->fib_nh_gw_family || 2993 fl6->flowi6_oif != nh->fib_nh_dev->ifindex) 2994 return false; 2995 2996 /* rt_cache's gateway might be different from its 'parent' 2997 * in the case of an ip redirect. 2998 * So we keep searching in the exception table if the gateway 2999 * is different. 3000 */ 3001 if (!ipv6_addr_equal(gw, &nh->fib_nh_gw6)) { 3002 struct rt6_info *rt_cache; 3003 3004 rt_cache = rt6_find_cached_rt(res, &fl6->daddr, &fl6->saddr); 3005 if (rt_cache && 3006 ipv6_addr_equal(gw, &rt_cache->rt6i_gateway)) { 3007 *ret = rt_cache; 3008 return true; 3009 } 3010 return false; 3011 } 3012 return true; 3013 } 3014 3015 struct fib6_nh_rd_arg { 3016 struct fib6_result *res; 3017 struct flowi6 *fl6; 3018 const struct in6_addr *gw; 3019 struct rt6_info **ret; 3020 }; 3021 3022 static int fib6_nh_redirect_match(struct fib6_nh *nh, void *_arg) 3023 { 3024 struct fib6_nh_rd_arg *arg = _arg; 3025 3026 arg->res->nh = nh; 3027 return ip6_redirect_nh_match(arg->res, arg->fl6, arg->gw, arg->ret); 3028 } 3029 3030 /* Handle redirects */ 3031 struct ip6rd_flowi { 3032 struct flowi6 fl6; 3033 struct in6_addr gateway; 3034 }; 3035 3036 INDIRECT_CALLABLE_SCOPE struct rt6_info *__ip6_route_redirect(struct net *net, 3037 struct fib6_table *table, 3038 struct flowi6 *fl6, 3039 const struct sk_buff *skb, 3040 int flags) 3041 { 3042 struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6; 3043 struct rt6_info *ret = NULL; 3044 struct fib6_result res = {}; 3045 struct fib6_nh_rd_arg arg = { 3046 .res = &res, 3047 .fl6 = fl6, 3048 .gw = &rdfl->gateway, 3049 .ret = &ret 3050 }; 3051 struct fib6_info *rt; 3052 struct fib6_node *fn; 3053 3054 /* Get the "current" route for this destination and 3055 * check if the redirect has come from appropriate router. 3056 * 3057 * RFC 4861 specifies that redirects should only be 3058 * accepted if they come from the nexthop to the target. 3059 * Due to the way the routes are chosen, this notion 3060 * is a bit fuzzy and one might need to check all possible 3061 * routes. 3062 */ 3063 3064 rcu_read_lock(); 3065 fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); 3066 restart: 3067 for_each_fib6_node_rt_rcu(fn) { 3068 res.f6i = rt; 3069 if (fib6_check_expired(rt)) 3070 continue; 3071 if (rt->fib6_flags & RTF_REJECT) 3072 break; 3073 if (unlikely(rt->nh)) { 3074 if (nexthop_is_blackhole(rt->nh)) 3075 continue; 3076 /* on match, res->nh is filled in and potentially ret */ 3077 if (nexthop_for_each_fib6_nh(rt->nh, 3078 fib6_nh_redirect_match, 3079 &arg)) 3080 goto out; 3081 } else { 3082 res.nh = rt->fib6_nh; 3083 if (ip6_redirect_nh_match(&res, fl6, &rdfl->gateway, 3084 &ret)) 3085 goto out; 3086 } 3087 } 3088 3089 if (!rt) 3090 rt = net->ipv6.fib6_null_entry; 3091 else if (rt->fib6_flags & RTF_REJECT) { 3092 ret = net->ipv6.ip6_null_entry; 3093 goto out; 3094 } 3095 3096 if (rt == net->ipv6.fib6_null_entry) { 3097 fn = fib6_backtrack(fn, &fl6->saddr); 3098 if (fn) 3099 goto restart; 3100 } 3101 3102 res.f6i = rt; 3103 res.nh = rt->fib6_nh; 3104 out: 3105 if (ret) { 3106 ip6_hold_safe(net, &ret); 3107 } else { 3108 res.fib6_flags = res.f6i->fib6_flags; 3109 res.fib6_type = res.f6i->fib6_type; 3110 ret = ip6_create_rt_rcu(&res); 3111 } 3112 3113 rcu_read_unlock(); 3114 3115 trace_fib6_table_lookup(net, &res, table, fl6); 3116 return ret; 3117 }; 3118 3119 static struct dst_entry *ip6_route_redirect(struct net *net, 3120 const struct flowi6 *fl6, 3121 const struct sk_buff *skb, 3122 const struct in6_addr *gateway) 3123 { 3124 int flags = RT6_LOOKUP_F_HAS_SADDR; 3125 struct ip6rd_flowi rdfl; 3126 3127 rdfl.fl6 = *fl6; 3128 rdfl.gateway = *gateway; 3129 3130 return fib6_rule_lookup(net, &rdfl.fl6, skb, 3131 flags, __ip6_route_redirect); 3132 } 3133 3134 void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark, 3135 kuid_t uid) 3136 { 3137 const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data; 3138 struct dst_entry *dst; 3139 struct flowi6 fl6 = { 3140 .flowi6_iif = LOOPBACK_IFINDEX, 3141 .flowi6_oif = oif, 3142 .flowi6_mark = mark, 3143 .daddr = iph->daddr, 3144 .saddr = iph->saddr, 3145 .flowlabel = ip6_flowinfo(iph), 3146 .flowi6_uid = uid, 3147 }; 3148 3149 dst = ip6_route_redirect(net, &fl6, skb, &ipv6_hdr(skb)->saddr); 3150 rt6_do_redirect(dst, NULL, skb); 3151 dst_release(dst); 3152 } 3153 EXPORT_SYMBOL_GPL(ip6_redirect); 3154 3155 void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif) 3156 { 3157 const struct ipv6hdr *iph = ipv6_hdr(skb); 3158 const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb); 3159 struct dst_entry *dst; 3160 struct flowi6 fl6 = { 3161 .flowi6_iif = LOOPBACK_IFINDEX, 3162 .flowi6_oif = oif, 3163 .daddr = msg->dest, 3164 .saddr = iph->daddr, 3165 .flowi6_uid = sock_net_uid(net, NULL), 3166 }; 3167 3168 dst = ip6_route_redirect(net, &fl6, skb, &iph->saddr); 3169 rt6_do_redirect(dst, NULL, skb); 3170 dst_release(dst); 3171 } 3172 3173 void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk) 3174 { 3175 ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if, 3176 READ_ONCE(sk->sk_mark), sk->sk_uid); 3177 } 3178 EXPORT_SYMBOL_GPL(ip6_sk_redirect); 3179 3180 static unsigned int ip6_default_advmss(const struct dst_entry *dst) 3181 { 3182 struct net_device *dev = dst->dev; 3183 unsigned int mtu = dst_mtu(dst); 3184 struct net *net = dev_net(dev); 3185 3186 mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr); 3187 3188 if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss) 3189 mtu = net->ipv6.sysctl.ip6_rt_min_advmss; 3190 3191 /* 3192 * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and 3193 * corresponding MSS is IPV6_MAXPLEN - tcp_header_size. 3194 * IPV6_MAXPLEN is also valid and means: "any MSS, 3195 * rely only on pmtu discovery" 3196 */ 3197 if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr)) 3198 mtu = IPV6_MAXPLEN; 3199 return mtu; 3200 } 3201 3202 INDIRECT_CALLABLE_SCOPE unsigned int ip6_mtu(const struct dst_entry *dst) 3203 { 3204 return ip6_dst_mtu_maybe_forward(dst, false); 3205 } 3206 EXPORT_INDIRECT_CALLABLE(ip6_mtu); 3207 3208 /* MTU selection: 3209 * 1. mtu on route is locked - use it 3210 * 2. mtu from nexthop exception 3211 * 3. mtu from egress device 3212 * 3213 * based on ip6_dst_mtu_forward and exception logic of 3214 * rt6_find_cached_rt; called with rcu_read_lock 3215 */ 3216 u32 ip6_mtu_from_fib6(const struct fib6_result *res, 3217 const struct in6_addr *daddr, 3218 const struct in6_addr *saddr) 3219 { 3220 const struct fib6_nh *nh = res->nh; 3221 struct fib6_info *f6i = res->f6i; 3222 struct inet6_dev *idev; 3223 struct rt6_info *rt; 3224 u32 mtu = 0; 3225 3226 if (unlikely(fib6_metric_locked(f6i, RTAX_MTU))) { 3227 mtu = f6i->fib6_pmtu; 3228 if (mtu) 3229 goto out; 3230 } 3231 3232 rt = rt6_find_cached_rt(res, daddr, saddr); 3233 if (unlikely(rt)) { 3234 mtu = dst_metric_raw(&rt->dst, RTAX_MTU); 3235 } else { 3236 struct net_device *dev = nh->fib_nh_dev; 3237 3238 mtu = IPV6_MIN_MTU; 3239 idev = __in6_dev_get(dev); 3240 if (idev && idev->cnf.mtu6 > mtu) 3241 mtu = idev->cnf.mtu6; 3242 } 3243 3244 mtu = min_t(unsigned int, mtu, IP6_MAX_MTU); 3245 out: 3246 return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu); 3247 } 3248 3249 struct dst_entry *icmp6_dst_alloc(struct net_device *dev, 3250 struct flowi6 *fl6) 3251 { 3252 struct dst_entry *dst; 3253 struct rt6_info *rt; 3254 struct inet6_dev *idev = in6_dev_get(dev); 3255 struct net *net = dev_net(dev); 3256 3257 if (unlikely(!idev)) 3258 return ERR_PTR(-ENODEV); 3259 3260 rt = ip6_dst_alloc(net, dev, 0); 3261 if (unlikely(!rt)) { 3262 in6_dev_put(idev); 3263 dst = ERR_PTR(-ENOMEM); 3264 goto out; 3265 } 3266 3267 rt->dst.input = ip6_input; 3268 rt->dst.output = ip6_output; 3269 rt->rt6i_gateway = fl6->daddr; 3270 rt->rt6i_dst.addr = fl6->daddr; 3271 rt->rt6i_dst.plen = 128; 3272 rt->rt6i_idev = idev; 3273 dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0); 3274 3275 /* Add this dst into uncached_list so that rt6_disable_ip() can 3276 * do proper release of the net_device 3277 */ 3278 rt6_uncached_list_add(rt); 3279 3280 dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0); 3281 3282 out: 3283 return dst; 3284 } 3285 3286 static void ip6_dst_gc(struct dst_ops *ops) 3287 { 3288 struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops); 3289 int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval; 3290 int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity; 3291 int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout; 3292 unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc; 3293 unsigned int val; 3294 int entries; 3295 3296 if (time_after(rt_last_gc + rt_min_interval, jiffies)) 3297 goto out; 3298 3299 fib6_run_gc(atomic_inc_return(&net->ipv6.ip6_rt_gc_expire), net, true); 3300 entries = dst_entries_get_slow(ops); 3301 if (entries < ops->gc_thresh) 3302 atomic_set(&net->ipv6.ip6_rt_gc_expire, rt_gc_timeout >> 1); 3303 out: 3304 val = atomic_read(&net->ipv6.ip6_rt_gc_expire); 3305 atomic_set(&net->ipv6.ip6_rt_gc_expire, val - (val >> rt_elasticity)); 3306 } 3307 3308 static int ip6_nh_lookup_table(struct net *net, struct fib6_config *cfg, 3309 const struct in6_addr *gw_addr, u32 tbid, 3310 int flags, struct fib6_result *res) 3311 { 3312 struct flowi6 fl6 = { 3313 .flowi6_oif = cfg->fc_ifindex, 3314 .daddr = *gw_addr, 3315 .saddr = cfg->fc_prefsrc, 3316 }; 3317 struct fib6_table *table; 3318 int err; 3319 3320 table = fib6_get_table(net, tbid); 3321 if (!table) 3322 return -EINVAL; 3323 3324 if (!ipv6_addr_any(&cfg->fc_prefsrc)) 3325 flags |= RT6_LOOKUP_F_HAS_SADDR; 3326 3327 flags |= RT6_LOOKUP_F_IGNORE_LINKSTATE; 3328 3329 err = fib6_table_lookup(net, table, cfg->fc_ifindex, &fl6, res, flags); 3330 if (!err && res->f6i != net->ipv6.fib6_null_entry) 3331 fib6_select_path(net, res, &fl6, cfg->fc_ifindex, 3332 cfg->fc_ifindex != 0, NULL, flags); 3333 3334 return err; 3335 } 3336 3337 static int ip6_route_check_nh_onlink(struct net *net, 3338 struct fib6_config *cfg, 3339 const struct net_device *dev, 3340 struct netlink_ext_ack *extack) 3341 { 3342 u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN; 3343 const struct in6_addr *gw_addr = &cfg->fc_gateway; 3344 struct fib6_result res = {}; 3345 int err; 3346 3347 err = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0, &res); 3348 if (!err && !(res.fib6_flags & RTF_REJECT) && 3349 /* ignore match if it is the default route */ 3350 !ipv6_addr_any(&res.f6i->fib6_dst.addr) && 3351 (res.fib6_type != RTN_UNICAST || dev != res.nh->fib_nh_dev)) { 3352 NL_SET_ERR_MSG(extack, 3353 "Nexthop has invalid gateway or device mismatch"); 3354 err = -EINVAL; 3355 } 3356 3357 return err; 3358 } 3359 3360 static int ip6_route_check_nh(struct net *net, 3361 struct fib6_config *cfg, 3362 struct net_device **_dev, 3363 netdevice_tracker *dev_tracker, 3364 struct inet6_dev **idev) 3365 { 3366 const struct in6_addr *gw_addr = &cfg->fc_gateway; 3367 struct net_device *dev = _dev ? *_dev : NULL; 3368 int flags = RT6_LOOKUP_F_IFACE; 3369 struct fib6_result res = {}; 3370 int err = -EHOSTUNREACH; 3371 3372 if (cfg->fc_table) { 3373 err = ip6_nh_lookup_table(net, cfg, gw_addr, 3374 cfg->fc_table, flags, &res); 3375 /* gw_addr can not require a gateway or resolve to a reject 3376 * route. If a device is given, it must match the result. 3377 */ 3378 if (err || res.fib6_flags & RTF_REJECT || 3379 res.nh->fib_nh_gw_family || 3380 (dev && dev != res.nh->fib_nh_dev)) 3381 err = -EHOSTUNREACH; 3382 } 3383 3384 if (err < 0) { 3385 struct flowi6 fl6 = { 3386 .flowi6_oif = cfg->fc_ifindex, 3387 .daddr = *gw_addr, 3388 }; 3389 3390 err = fib6_lookup(net, cfg->fc_ifindex, &fl6, &res, flags); 3391 if (err || res.fib6_flags & RTF_REJECT || 3392 res.nh->fib_nh_gw_family) 3393 err = -EHOSTUNREACH; 3394 3395 if (err) 3396 return err; 3397 3398 fib6_select_path(net, &res, &fl6, cfg->fc_ifindex, 3399 cfg->fc_ifindex != 0, NULL, flags); 3400 } 3401 3402 err = 0; 3403 if (dev) { 3404 if (dev != res.nh->fib_nh_dev) 3405 err = -EHOSTUNREACH; 3406 } else { 3407 *_dev = dev = res.nh->fib_nh_dev; 3408 netdev_hold(dev, dev_tracker, GFP_ATOMIC); 3409 *idev = in6_dev_get(dev); 3410 } 3411 3412 return err; 3413 } 3414 3415 static int ip6_validate_gw(struct net *net, struct fib6_config *cfg, 3416 struct net_device **_dev, 3417 netdevice_tracker *dev_tracker, 3418 struct inet6_dev **idev, 3419 struct netlink_ext_ack *extack) 3420 { 3421 const struct in6_addr *gw_addr = &cfg->fc_gateway; 3422 int gwa_type = ipv6_addr_type(gw_addr); 3423 bool skip_dev = gwa_type & IPV6_ADDR_LINKLOCAL ? false : true; 3424 const struct net_device *dev = *_dev; 3425 bool need_addr_check = !dev; 3426 int err = -EINVAL; 3427 3428 /* if gw_addr is local we will fail to detect this in case 3429 * address is still TENTATIVE (DAD in progress). rt6_lookup() 3430 * will return already-added prefix route via interface that 3431 * prefix route was assigned to, which might be non-loopback. 3432 */ 3433 if (dev && 3434 ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) { 3435 NL_SET_ERR_MSG(extack, "Gateway can not be a local address"); 3436 goto out; 3437 } 3438 3439 if (gwa_type != (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST)) { 3440 /* IPv6 strictly inhibits using not link-local 3441 * addresses as nexthop address. 3442 * Otherwise, router will not able to send redirects. 3443 * It is very good, but in some (rare!) circumstances 3444 * (SIT, PtP, NBMA NOARP links) it is handy to allow 3445 * some exceptions. --ANK 3446 * We allow IPv4-mapped nexthops to support RFC4798-type 3447 * addressing 3448 */ 3449 if (!(gwa_type & (IPV6_ADDR_UNICAST | IPV6_ADDR_MAPPED))) { 3450 NL_SET_ERR_MSG(extack, "Invalid gateway address"); 3451 goto out; 3452 } 3453 3454 rcu_read_lock(); 3455 3456 if (cfg->fc_flags & RTNH_F_ONLINK) 3457 err = ip6_route_check_nh_onlink(net, cfg, dev, extack); 3458 else 3459 err = ip6_route_check_nh(net, cfg, _dev, dev_tracker, 3460 idev); 3461 3462 rcu_read_unlock(); 3463 3464 if (err) 3465 goto out; 3466 } 3467 3468 /* reload in case device was changed */ 3469 dev = *_dev; 3470 3471 err = -EINVAL; 3472 if (!dev) { 3473 NL_SET_ERR_MSG(extack, "Egress device not specified"); 3474 goto out; 3475 } else if (dev->flags & IFF_LOOPBACK) { 3476 NL_SET_ERR_MSG(extack, 3477 "Egress device can not be loopback device for this route"); 3478 goto out; 3479 } 3480 3481 /* if we did not check gw_addr above, do so now that the 3482 * egress device has been resolved. 3483 */ 3484 if (need_addr_check && 3485 ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) { 3486 NL_SET_ERR_MSG(extack, "Gateway can not be a local address"); 3487 goto out; 3488 } 3489 3490 err = 0; 3491 out: 3492 return err; 3493 } 3494 3495 static bool fib6_is_reject(u32 flags, struct net_device *dev, int addr_type) 3496 { 3497 if ((flags & RTF_REJECT) || 3498 (dev && (dev->flags & IFF_LOOPBACK) && 3499 !(addr_type & IPV6_ADDR_LOOPBACK) && 3500 !(flags & (RTF_ANYCAST | RTF_LOCAL)))) 3501 return true; 3502 3503 return false; 3504 } 3505 3506 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh, 3507 struct fib6_config *cfg, gfp_t gfp_flags, 3508 struct netlink_ext_ack *extack) 3509 { 3510 netdevice_tracker *dev_tracker = &fib6_nh->fib_nh_dev_tracker; 3511 struct net_device *dev = NULL; 3512 struct inet6_dev *idev = NULL; 3513 int addr_type; 3514 int err; 3515 3516 fib6_nh->fib_nh_family = AF_INET6; 3517 #ifdef CONFIG_IPV6_ROUTER_PREF 3518 fib6_nh->last_probe = jiffies; 3519 #endif 3520 if (cfg->fc_is_fdb) { 3521 fib6_nh->fib_nh_gw6 = cfg->fc_gateway; 3522 fib6_nh->fib_nh_gw_family = AF_INET6; 3523 return 0; 3524 } 3525 3526 err = -ENODEV; 3527 if (cfg->fc_ifindex) { 3528 dev = netdev_get_by_index(net, cfg->fc_ifindex, 3529 dev_tracker, gfp_flags); 3530 if (!dev) 3531 goto out; 3532 idev = in6_dev_get(dev); 3533 if (!idev) 3534 goto out; 3535 } 3536 3537 if (cfg->fc_flags & RTNH_F_ONLINK) { 3538 if (!dev) { 3539 NL_SET_ERR_MSG(extack, 3540 "Nexthop device required for onlink"); 3541 goto out; 3542 } 3543 3544 if (!(dev->flags & IFF_UP)) { 3545 NL_SET_ERR_MSG(extack, "Nexthop device is not up"); 3546 err = -ENETDOWN; 3547 goto out; 3548 } 3549 3550 fib6_nh->fib_nh_flags |= RTNH_F_ONLINK; 3551 } 3552 3553 fib6_nh->fib_nh_weight = 1; 3554 3555 /* We cannot add true routes via loopback here, 3556 * they would result in kernel looping; promote them to reject routes 3557 */ 3558 addr_type = ipv6_addr_type(&cfg->fc_dst); 3559 if (fib6_is_reject(cfg->fc_flags, dev, addr_type)) { 3560 /* hold loopback dev/idev if we haven't done so. */ 3561 if (dev != net->loopback_dev) { 3562 if (dev) { 3563 netdev_put(dev, dev_tracker); 3564 in6_dev_put(idev); 3565 } 3566 dev = net->loopback_dev; 3567 netdev_hold(dev, dev_tracker, gfp_flags); 3568 idev = in6_dev_get(dev); 3569 if (!idev) { 3570 err = -ENODEV; 3571 goto out; 3572 } 3573 } 3574 goto pcpu_alloc; 3575 } 3576 3577 if (cfg->fc_flags & RTF_GATEWAY) { 3578 err = ip6_validate_gw(net, cfg, &dev, dev_tracker, 3579 &idev, extack); 3580 if (err) 3581 goto out; 3582 3583 fib6_nh->fib_nh_gw6 = cfg->fc_gateway; 3584 fib6_nh->fib_nh_gw_family = AF_INET6; 3585 } 3586 3587 err = -ENODEV; 3588 if (!dev) 3589 goto out; 3590 3591 if (idev->cnf.disable_ipv6) { 3592 NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device"); 3593 err = -EACCES; 3594 goto out; 3595 } 3596 3597 if (!(dev->flags & IFF_UP) && !cfg->fc_ignore_dev_down) { 3598 NL_SET_ERR_MSG(extack, "Nexthop device is not up"); 3599 err = -ENETDOWN; 3600 goto out; 3601 } 3602 3603 if (!(cfg->fc_flags & (RTF_LOCAL | RTF_ANYCAST)) && 3604 !netif_carrier_ok(dev)) 3605 fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN; 3606 3607 err = fib_nh_common_init(net, &fib6_nh->nh_common, cfg->fc_encap, 3608 cfg->fc_encap_type, cfg, gfp_flags, extack); 3609 if (err) 3610 goto out; 3611 3612 pcpu_alloc: 3613 fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags); 3614 if (!fib6_nh->rt6i_pcpu) { 3615 err = -ENOMEM; 3616 goto out; 3617 } 3618 3619 fib6_nh->fib_nh_dev = dev; 3620 fib6_nh->fib_nh_oif = dev->ifindex; 3621 err = 0; 3622 out: 3623 if (idev) 3624 in6_dev_put(idev); 3625 3626 if (err) { 3627 lwtstate_put(fib6_nh->fib_nh_lws); 3628 fib6_nh->fib_nh_lws = NULL; 3629 netdev_put(dev, dev_tracker); 3630 } 3631 3632 return err; 3633 } 3634 3635 void fib6_nh_release(struct fib6_nh *fib6_nh) 3636 { 3637 struct rt6_exception_bucket *bucket; 3638 3639 rcu_read_lock(); 3640 3641 fib6_nh_flush_exceptions(fib6_nh, NULL); 3642 bucket = fib6_nh_get_excptn_bucket(fib6_nh, NULL); 3643 if (bucket) { 3644 rcu_assign_pointer(fib6_nh->rt6i_exception_bucket, NULL); 3645 kfree(bucket); 3646 } 3647 3648 rcu_read_unlock(); 3649 3650 fib6_nh_release_dsts(fib6_nh); 3651 free_percpu(fib6_nh->rt6i_pcpu); 3652 3653 fib_nh_common_release(&fib6_nh->nh_common); 3654 } 3655 3656 void fib6_nh_release_dsts(struct fib6_nh *fib6_nh) 3657 { 3658 int cpu; 3659 3660 if (!fib6_nh->rt6i_pcpu) 3661 return; 3662 3663 for_each_possible_cpu(cpu) { 3664 struct rt6_info *pcpu_rt, **ppcpu_rt; 3665 3666 ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu); 3667 pcpu_rt = xchg(ppcpu_rt, NULL); 3668 if (pcpu_rt) { 3669 dst_dev_put(&pcpu_rt->dst); 3670 dst_release(&pcpu_rt->dst); 3671 } 3672 } 3673 } 3674 3675 static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg, 3676 gfp_t gfp_flags, 3677 struct netlink_ext_ack *extack) 3678 { 3679 struct net *net = cfg->fc_nlinfo.nl_net; 3680 struct fib6_info *rt = NULL; 3681 struct nexthop *nh = NULL; 3682 struct fib6_table *table; 3683 struct fib6_nh *fib6_nh; 3684 int err = -EINVAL; 3685 int addr_type; 3686 3687 /* RTF_PCPU is an internal flag; can not be set by userspace */ 3688 if (cfg->fc_flags & RTF_PCPU) { 3689 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_PCPU"); 3690 goto out; 3691 } 3692 3693 /* RTF_CACHE is an internal flag; can not be set by userspace */ 3694 if (cfg->fc_flags & RTF_CACHE) { 3695 NL_SET_ERR_MSG(extack, "Userspace can not set RTF_CACHE"); 3696 goto out; 3697 } 3698 3699 if (cfg->fc_type > RTN_MAX) { 3700 NL_SET_ERR_MSG(extack, "Invalid route type"); 3701 goto out; 3702 } 3703 3704 if (cfg->fc_dst_len > 128) { 3705 NL_SET_ERR_MSG(extack, "Invalid prefix length"); 3706 goto out; 3707 } 3708 if (cfg->fc_src_len > 128) { 3709 NL_SET_ERR_MSG(extack, "Invalid source address length"); 3710 goto out; 3711 } 3712 #ifndef CONFIG_IPV6_SUBTREES 3713 if (cfg->fc_src_len) { 3714 NL_SET_ERR_MSG(extack, 3715 "Specifying source address requires IPV6_SUBTREES to be enabled"); 3716 goto out; 3717 } 3718 #endif 3719 if (cfg->fc_nh_id) { 3720 nh = nexthop_find_by_id(net, cfg->fc_nh_id); 3721 if (!nh) { 3722 NL_SET_ERR_MSG(extack, "Nexthop id does not exist"); 3723 goto out; 3724 } 3725 err = fib6_check_nexthop(nh, cfg, extack); 3726 if (err) 3727 goto out; 3728 } 3729 3730 err = -ENOBUFS; 3731 if (cfg->fc_nlinfo.nlh && 3732 !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) { 3733 table = fib6_get_table(net, cfg->fc_table); 3734 if (!table) { 3735 pr_warn("NLM_F_CREATE should be specified when creating new route\n"); 3736 table = fib6_new_table(net, cfg->fc_table); 3737 } 3738 } else { 3739 table = fib6_new_table(net, cfg->fc_table); 3740 } 3741 3742 if (!table) 3743 goto out; 3744 3745 err = -ENOMEM; 3746 rt = fib6_info_alloc(gfp_flags, !nh); 3747 if (!rt) 3748 goto out; 3749 3750 rt->fib6_metrics = ip_fib_metrics_init(net, cfg->fc_mx, cfg->fc_mx_len, 3751 extack); 3752 if (IS_ERR(rt->fib6_metrics)) { 3753 err = PTR_ERR(rt->fib6_metrics); 3754 /* Do not leave garbage there. */ 3755 rt->fib6_metrics = (struct dst_metrics *)&dst_default_metrics; 3756 goto out_free; 3757 } 3758 3759 if (cfg->fc_flags & RTF_ADDRCONF) 3760 rt->dst_nocount = true; 3761 3762 if (cfg->fc_flags & RTF_EXPIRES) 3763 fib6_set_expires_locked(rt, jiffies + 3764 clock_t_to_jiffies(cfg->fc_expires)); 3765 else 3766 fib6_clean_expires_locked(rt); 3767 3768 if (cfg->fc_protocol == RTPROT_UNSPEC) 3769 cfg->fc_protocol = RTPROT_BOOT; 3770 rt->fib6_protocol = cfg->fc_protocol; 3771 3772 rt->fib6_table = table; 3773 rt->fib6_metric = cfg->fc_metric; 3774 rt->fib6_type = cfg->fc_type ? : RTN_UNICAST; 3775 rt->fib6_flags = cfg->fc_flags & ~RTF_GATEWAY; 3776 3777 ipv6_addr_prefix(&rt->fib6_dst.addr, &cfg->fc_dst, cfg->fc_dst_len); 3778 rt->fib6_dst.plen = cfg->fc_dst_len; 3779 3780 #ifdef CONFIG_IPV6_SUBTREES 3781 ipv6_addr_prefix(&rt->fib6_src.addr, &cfg->fc_src, cfg->fc_src_len); 3782 rt->fib6_src.plen = cfg->fc_src_len; 3783 #endif 3784 if (nh) { 3785 if (rt->fib6_src.plen) { 3786 NL_SET_ERR_MSG(extack, "Nexthops can not be used with source routing"); 3787 goto out_free; 3788 } 3789 if (!nexthop_get(nh)) { 3790 NL_SET_ERR_MSG(extack, "Nexthop has been deleted"); 3791 goto out_free; 3792 } 3793 rt->nh = nh; 3794 fib6_nh = nexthop_fib6_nh(rt->nh); 3795 } else { 3796 err = fib6_nh_init(net, rt->fib6_nh, cfg, gfp_flags, extack); 3797 if (err) 3798 goto out; 3799 3800 fib6_nh = rt->fib6_nh; 3801 3802 /* We cannot add true routes via loopback here, they would 3803 * result in kernel looping; promote them to reject routes 3804 */ 3805 addr_type = ipv6_addr_type(&cfg->fc_dst); 3806 if (fib6_is_reject(cfg->fc_flags, rt->fib6_nh->fib_nh_dev, 3807 addr_type)) 3808 rt->fib6_flags = RTF_REJECT | RTF_NONEXTHOP; 3809 } 3810 3811 if (!ipv6_addr_any(&cfg->fc_prefsrc)) { 3812 struct net_device *dev = fib6_nh->fib_nh_dev; 3813 3814 if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) { 3815 NL_SET_ERR_MSG(extack, "Invalid source address"); 3816 err = -EINVAL; 3817 goto out; 3818 } 3819 rt->fib6_prefsrc.addr = cfg->fc_prefsrc; 3820 rt->fib6_prefsrc.plen = 128; 3821 } else 3822 rt->fib6_prefsrc.plen = 0; 3823 3824 return rt; 3825 out: 3826 fib6_info_release(rt); 3827 return ERR_PTR(err); 3828 out_free: 3829 ip_fib_metrics_put(rt->fib6_metrics); 3830 kfree(rt); 3831 return ERR_PTR(err); 3832 } 3833 3834 int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags, 3835 struct netlink_ext_ack *extack) 3836 { 3837 struct fib6_info *rt; 3838 int err; 3839 3840 rt = ip6_route_info_create(cfg, gfp_flags, extack); 3841 if (IS_ERR(rt)) 3842 return PTR_ERR(rt); 3843 3844 err = __ip6_ins_rt(rt, &cfg->fc_nlinfo, extack); 3845 fib6_info_release(rt); 3846 3847 return err; 3848 } 3849 3850 static int __ip6_del_rt(struct fib6_info *rt, struct nl_info *info) 3851 { 3852 struct net *net = info->nl_net; 3853 struct fib6_table *table; 3854 int err; 3855 3856 if (rt == net->ipv6.fib6_null_entry) { 3857 err = -ENOENT; 3858 goto out; 3859 } 3860 3861 table = rt->fib6_table; 3862 spin_lock_bh(&table->tb6_lock); 3863 err = fib6_del(rt, info); 3864 spin_unlock_bh(&table->tb6_lock); 3865 3866 out: 3867 fib6_info_release(rt); 3868 return err; 3869 } 3870 3871 int ip6_del_rt(struct net *net, struct fib6_info *rt, bool skip_notify) 3872 { 3873 struct nl_info info = { 3874 .nl_net = net, 3875 .skip_notify = skip_notify 3876 }; 3877 3878 return __ip6_del_rt(rt, &info); 3879 } 3880 3881 static int __ip6_del_rt_siblings(struct fib6_info *rt, struct fib6_config *cfg) 3882 { 3883 struct nl_info *info = &cfg->fc_nlinfo; 3884 struct net *net = info->nl_net; 3885 struct sk_buff *skb = NULL; 3886 struct fib6_table *table; 3887 int err = -ENOENT; 3888 3889 if (rt == net->ipv6.fib6_null_entry) 3890 goto out_put; 3891 table = rt->fib6_table; 3892 spin_lock_bh(&table->tb6_lock); 3893 3894 if (rt->fib6_nsiblings && cfg->fc_delete_all_nh) { 3895 struct fib6_info *sibling, *next_sibling; 3896 struct fib6_node *fn; 3897 3898 /* prefer to send a single notification with all hops */ 3899 skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any()); 3900 if (skb) { 3901 u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; 3902 3903 if (rt6_fill_node(net, skb, rt, NULL, 3904 NULL, NULL, 0, RTM_DELROUTE, 3905 info->portid, seq, 0) < 0) { 3906 kfree_skb(skb); 3907 skb = NULL; 3908 } else 3909 info->skip_notify = 1; 3910 } 3911 3912 /* 'rt' points to the first sibling route. If it is not the 3913 * leaf, then we do not need to send a notification. Otherwise, 3914 * we need to check if the last sibling has a next route or not 3915 * and emit a replace or delete notification, respectively. 3916 */ 3917 info->skip_notify_kernel = 1; 3918 fn = rcu_dereference_protected(rt->fib6_node, 3919 lockdep_is_held(&table->tb6_lock)); 3920 if (rcu_access_pointer(fn->leaf) == rt) { 3921 struct fib6_info *last_sibling, *replace_rt; 3922 3923 last_sibling = list_last_entry(&rt->fib6_siblings, 3924 struct fib6_info, 3925 fib6_siblings); 3926 replace_rt = rcu_dereference_protected( 3927 last_sibling->fib6_next, 3928 lockdep_is_held(&table->tb6_lock)); 3929 if (replace_rt) 3930 call_fib6_entry_notifiers_replace(net, 3931 replace_rt); 3932 else 3933 call_fib6_multipath_entry_notifiers(net, 3934 FIB_EVENT_ENTRY_DEL, 3935 rt, rt->fib6_nsiblings, 3936 NULL); 3937 } 3938 list_for_each_entry_safe(sibling, next_sibling, 3939 &rt->fib6_siblings, 3940 fib6_siblings) { 3941 err = fib6_del(sibling, info); 3942 if (err) 3943 goto out_unlock; 3944 } 3945 } 3946 3947 err = fib6_del(rt, info); 3948 out_unlock: 3949 spin_unlock_bh(&table->tb6_lock); 3950 out_put: 3951 fib6_info_release(rt); 3952 3953 if (skb) { 3954 rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE, 3955 info->nlh, gfp_any()); 3956 } 3957 return err; 3958 } 3959 3960 static int __ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg) 3961 { 3962 int rc = -ESRCH; 3963 3964 if (cfg->fc_ifindex && rt->dst.dev->ifindex != cfg->fc_ifindex) 3965 goto out; 3966 3967 if (cfg->fc_flags & RTF_GATEWAY && 3968 !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway)) 3969 goto out; 3970 3971 rc = rt6_remove_exception_rt(rt); 3972 out: 3973 return rc; 3974 } 3975 3976 static int ip6_del_cached_rt(struct fib6_config *cfg, struct fib6_info *rt, 3977 struct fib6_nh *nh) 3978 { 3979 struct fib6_result res = { 3980 .f6i = rt, 3981 .nh = nh, 3982 }; 3983 struct rt6_info *rt_cache; 3984 3985 rt_cache = rt6_find_cached_rt(&res, &cfg->fc_dst, &cfg->fc_src); 3986 if (rt_cache) 3987 return __ip6_del_cached_rt(rt_cache, cfg); 3988 3989 return 0; 3990 } 3991 3992 struct fib6_nh_del_cached_rt_arg { 3993 struct fib6_config *cfg; 3994 struct fib6_info *f6i; 3995 }; 3996 3997 static int fib6_nh_del_cached_rt(struct fib6_nh *nh, void *_arg) 3998 { 3999 struct fib6_nh_del_cached_rt_arg *arg = _arg; 4000 int rc; 4001 4002 rc = ip6_del_cached_rt(arg->cfg, arg->f6i, nh); 4003 return rc != -ESRCH ? rc : 0; 4004 } 4005 4006 static int ip6_del_cached_rt_nh(struct fib6_config *cfg, struct fib6_info *f6i) 4007 { 4008 struct fib6_nh_del_cached_rt_arg arg = { 4009 .cfg = cfg, 4010 .f6i = f6i 4011 }; 4012 4013 return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_del_cached_rt, &arg); 4014 } 4015 4016 static int ip6_route_del(struct fib6_config *cfg, 4017 struct netlink_ext_ack *extack) 4018 { 4019 struct fib6_table *table; 4020 struct fib6_info *rt; 4021 struct fib6_node *fn; 4022 int err = -ESRCH; 4023 4024 table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table); 4025 if (!table) { 4026 NL_SET_ERR_MSG(extack, "FIB table does not exist"); 4027 return err; 4028 } 4029 4030 rcu_read_lock(); 4031 4032 fn = fib6_locate(&table->tb6_root, 4033 &cfg->fc_dst, cfg->fc_dst_len, 4034 &cfg->fc_src, cfg->fc_src_len, 4035 !(cfg->fc_flags & RTF_CACHE)); 4036 4037 if (fn) { 4038 for_each_fib6_node_rt_rcu(fn) { 4039 struct fib6_nh *nh; 4040 4041 if (rt->nh && cfg->fc_nh_id && 4042 rt->nh->id != cfg->fc_nh_id) 4043 continue; 4044 4045 if (cfg->fc_flags & RTF_CACHE) { 4046 int rc = 0; 4047 4048 if (rt->nh) { 4049 rc = ip6_del_cached_rt_nh(cfg, rt); 4050 } else if (cfg->fc_nh_id) { 4051 continue; 4052 } else { 4053 nh = rt->fib6_nh; 4054 rc = ip6_del_cached_rt(cfg, rt, nh); 4055 } 4056 if (rc != -ESRCH) { 4057 rcu_read_unlock(); 4058 return rc; 4059 } 4060 continue; 4061 } 4062 4063 if (cfg->fc_metric && cfg->fc_metric != rt->fib6_metric) 4064 continue; 4065 if (cfg->fc_protocol && 4066 cfg->fc_protocol != rt->fib6_protocol) 4067 continue; 4068 4069 if (rt->nh) { 4070 if (!fib6_info_hold_safe(rt)) 4071 continue; 4072 rcu_read_unlock(); 4073 4074 return __ip6_del_rt(rt, &cfg->fc_nlinfo); 4075 } 4076 if (cfg->fc_nh_id) 4077 continue; 4078 4079 nh = rt->fib6_nh; 4080 if (cfg->fc_ifindex && 4081 (!nh->fib_nh_dev || 4082 nh->fib_nh_dev->ifindex != cfg->fc_ifindex)) 4083 continue; 4084 if (cfg->fc_flags & RTF_GATEWAY && 4085 !ipv6_addr_equal(&cfg->fc_gateway, &nh->fib_nh_gw6)) 4086 continue; 4087 if (!fib6_info_hold_safe(rt)) 4088 continue; 4089 rcu_read_unlock(); 4090 4091 /* if gateway was specified only delete the one hop */ 4092 if (cfg->fc_flags & RTF_GATEWAY) 4093 return __ip6_del_rt(rt, &cfg->fc_nlinfo); 4094 4095 return __ip6_del_rt_siblings(rt, cfg); 4096 } 4097 } 4098 rcu_read_unlock(); 4099 4100 return err; 4101 } 4102 4103 static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) 4104 { 4105 struct netevent_redirect netevent; 4106 struct rt6_info *rt, *nrt = NULL; 4107 struct fib6_result res = {}; 4108 struct ndisc_options ndopts; 4109 struct inet6_dev *in6_dev; 4110 struct neighbour *neigh; 4111 struct rd_msg *msg; 4112 int optlen, on_link; 4113 u8 *lladdr; 4114 4115 optlen = skb_tail_pointer(skb) - skb_transport_header(skb); 4116 optlen -= sizeof(*msg); 4117 4118 if (optlen < 0) { 4119 net_dbg_ratelimited("rt6_do_redirect: packet too short\n"); 4120 return; 4121 } 4122 4123 msg = (struct rd_msg *)icmp6_hdr(skb); 4124 4125 if (ipv6_addr_is_multicast(&msg->dest)) { 4126 net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n"); 4127 return; 4128 } 4129 4130 on_link = 0; 4131 if (ipv6_addr_equal(&msg->dest, &msg->target)) { 4132 on_link = 1; 4133 } else if (ipv6_addr_type(&msg->target) != 4134 (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { 4135 net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n"); 4136 return; 4137 } 4138 4139 in6_dev = __in6_dev_get(skb->dev); 4140 if (!in6_dev) 4141 return; 4142 if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) 4143 return; 4144 4145 /* RFC2461 8.1: 4146 * The IP source address of the Redirect MUST be the same as the current 4147 * first-hop router for the specified ICMP Destination Address. 4148 */ 4149 4150 if (!ndisc_parse_options(skb->dev, msg->opt, optlen, &ndopts)) { 4151 net_dbg_ratelimited("rt6_redirect: invalid ND options\n"); 4152 return; 4153 } 4154 4155 lladdr = NULL; 4156 if (ndopts.nd_opts_tgt_lladdr) { 4157 lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, 4158 skb->dev); 4159 if (!lladdr) { 4160 net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n"); 4161 return; 4162 } 4163 } 4164 4165 rt = (struct rt6_info *) dst; 4166 if (rt->rt6i_flags & RTF_REJECT) { 4167 net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n"); 4168 return; 4169 } 4170 4171 /* Redirect received -> path was valid. 4172 * Look, redirects are sent only in response to data packets, 4173 * so that this nexthop apparently is reachable. --ANK 4174 */ 4175 dst_confirm_neigh(&rt->dst, &ipv6_hdr(skb)->saddr); 4176 4177 neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1); 4178 if (!neigh) 4179 return; 4180 4181 /* 4182 * We have finally decided to accept it. 4183 */ 4184 4185 ndisc_update(skb->dev, neigh, lladdr, NUD_STALE, 4186 NEIGH_UPDATE_F_WEAK_OVERRIDE| 4187 NEIGH_UPDATE_F_OVERRIDE| 4188 (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER| 4189 NEIGH_UPDATE_F_ISROUTER)), 4190 NDISC_REDIRECT, &ndopts); 4191 4192 rcu_read_lock(); 4193 res.f6i = rcu_dereference(rt->from); 4194 if (!res.f6i) 4195 goto out; 4196 4197 if (res.f6i->nh) { 4198 struct fib6_nh_match_arg arg = { 4199 .dev = dst->dev, 4200 .gw = &rt->rt6i_gateway, 4201 }; 4202 4203 nexthop_for_each_fib6_nh(res.f6i->nh, 4204 fib6_nh_find_match, &arg); 4205 4206 /* fib6_info uses a nexthop that does not have fib6_nh 4207 * using the dst->dev. Should be impossible 4208 */ 4209 if (!arg.match) 4210 goto out; 4211 res.nh = arg.match; 4212 } else { 4213 res.nh = res.f6i->fib6_nh; 4214 } 4215 4216 res.fib6_flags = res.f6i->fib6_flags; 4217 res.fib6_type = res.f6i->fib6_type; 4218 nrt = ip6_rt_cache_alloc(&res, &msg->dest, NULL); 4219 if (!nrt) 4220 goto out; 4221 4222 nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE; 4223 if (on_link) 4224 nrt->rt6i_flags &= ~RTF_GATEWAY; 4225 4226 nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key; 4227 4228 /* rt6_insert_exception() will take care of duplicated exceptions */ 4229 if (rt6_insert_exception(nrt, &res)) { 4230 dst_release_immediate(&nrt->dst); 4231 goto out; 4232 } 4233 4234 netevent.old = &rt->dst; 4235 netevent.new = &nrt->dst; 4236 netevent.daddr = &msg->dest; 4237 netevent.neigh = neigh; 4238 call_netevent_notifiers(NETEVENT_REDIRECT, &netevent); 4239 4240 out: 4241 rcu_read_unlock(); 4242 neigh_release(neigh); 4243 } 4244 4245 #ifdef CONFIG_IPV6_ROUTE_INFO 4246 static struct fib6_info *rt6_get_route_info(struct net *net, 4247 const struct in6_addr *prefix, int prefixlen, 4248 const struct in6_addr *gwaddr, 4249 struct net_device *dev) 4250 { 4251 u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO; 4252 int ifindex = dev->ifindex; 4253 struct fib6_node *fn; 4254 struct fib6_info *rt = NULL; 4255 struct fib6_table *table; 4256 4257 table = fib6_get_table(net, tb_id); 4258 if (!table) 4259 return NULL; 4260 4261 rcu_read_lock(); 4262 fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0, true); 4263 if (!fn) 4264 goto out; 4265 4266 for_each_fib6_node_rt_rcu(fn) { 4267 /* these routes do not use nexthops */ 4268 if (rt->nh) 4269 continue; 4270 if (rt->fib6_nh->fib_nh_dev->ifindex != ifindex) 4271 continue; 4272 if (!(rt->fib6_flags & RTF_ROUTEINFO) || 4273 !rt->fib6_nh->fib_nh_gw_family) 4274 continue; 4275 if (!ipv6_addr_equal(&rt->fib6_nh->fib_nh_gw6, gwaddr)) 4276 continue; 4277 if (!fib6_info_hold_safe(rt)) 4278 continue; 4279 break; 4280 } 4281 out: 4282 rcu_read_unlock(); 4283 return rt; 4284 } 4285 4286 static struct fib6_info *rt6_add_route_info(struct net *net, 4287 const struct in6_addr *prefix, int prefixlen, 4288 const struct in6_addr *gwaddr, 4289 struct net_device *dev, 4290 unsigned int pref) 4291 { 4292 struct fib6_config cfg = { 4293 .fc_metric = IP6_RT_PRIO_USER, 4294 .fc_ifindex = dev->ifindex, 4295 .fc_dst_len = prefixlen, 4296 .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO | 4297 RTF_UP | RTF_PREF(pref), 4298 .fc_protocol = RTPROT_RA, 4299 .fc_type = RTN_UNICAST, 4300 .fc_nlinfo.portid = 0, 4301 .fc_nlinfo.nlh = NULL, 4302 .fc_nlinfo.nl_net = net, 4303 }; 4304 4305 cfg.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO; 4306 cfg.fc_dst = *prefix; 4307 cfg.fc_gateway = *gwaddr; 4308 4309 /* We should treat it as a default route if prefix length is 0. */ 4310 if (!prefixlen) 4311 cfg.fc_flags |= RTF_DEFAULT; 4312 4313 ip6_route_add(&cfg, GFP_ATOMIC, NULL); 4314 4315 return rt6_get_route_info(net, prefix, prefixlen, gwaddr, dev); 4316 } 4317 #endif 4318 4319 struct fib6_info *rt6_get_dflt_router(struct net *net, 4320 const struct in6_addr *addr, 4321 struct net_device *dev) 4322 { 4323 u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT; 4324 struct fib6_info *rt; 4325 struct fib6_table *table; 4326 4327 table = fib6_get_table(net, tb_id); 4328 if (!table) 4329 return NULL; 4330 4331 rcu_read_lock(); 4332 for_each_fib6_node_rt_rcu(&table->tb6_root) { 4333 struct fib6_nh *nh; 4334 4335 /* RA routes do not use nexthops */ 4336 if (rt->nh) 4337 continue; 4338 4339 nh = rt->fib6_nh; 4340 if (dev == nh->fib_nh_dev && 4341 ((rt->fib6_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) && 4342 ipv6_addr_equal(&nh->fib_nh_gw6, addr)) 4343 break; 4344 } 4345 if (rt && !fib6_info_hold_safe(rt)) 4346 rt = NULL; 4347 rcu_read_unlock(); 4348 return rt; 4349 } 4350 4351 struct fib6_info *rt6_add_dflt_router(struct net *net, 4352 const struct in6_addr *gwaddr, 4353 struct net_device *dev, 4354 unsigned int pref, 4355 u32 defrtr_usr_metric) 4356 { 4357 struct fib6_config cfg = { 4358 .fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT, 4359 .fc_metric = defrtr_usr_metric, 4360 .fc_ifindex = dev->ifindex, 4361 .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT | 4362 RTF_UP | RTF_EXPIRES | RTF_PREF(pref), 4363 .fc_protocol = RTPROT_RA, 4364 .fc_type = RTN_UNICAST, 4365 .fc_nlinfo.portid = 0, 4366 .fc_nlinfo.nlh = NULL, 4367 .fc_nlinfo.nl_net = net, 4368 }; 4369 4370 cfg.fc_gateway = *gwaddr; 4371 4372 if (!ip6_route_add(&cfg, GFP_ATOMIC, NULL)) { 4373 struct fib6_table *table; 4374 4375 table = fib6_get_table(dev_net(dev), cfg.fc_table); 4376 if (table) 4377 table->flags |= RT6_TABLE_HAS_DFLT_ROUTER; 4378 } 4379 4380 return rt6_get_dflt_router(net, gwaddr, dev); 4381 } 4382 4383 static void __rt6_purge_dflt_routers(struct net *net, 4384 struct fib6_table *table) 4385 { 4386 struct fib6_info *rt; 4387 4388 restart: 4389 rcu_read_lock(); 4390 for_each_fib6_node_rt_rcu(&table->tb6_root) { 4391 struct net_device *dev = fib6_info_nh_dev(rt); 4392 struct inet6_dev *idev = dev ? __in6_dev_get(dev) : NULL; 4393 4394 if (rt->fib6_flags & (RTF_DEFAULT | RTF_ADDRCONF) && 4395 (!idev || idev->cnf.accept_ra != 2) && 4396 fib6_info_hold_safe(rt)) { 4397 rcu_read_unlock(); 4398 ip6_del_rt(net, rt, false); 4399 goto restart; 4400 } 4401 } 4402 rcu_read_unlock(); 4403 4404 table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER; 4405 } 4406 4407 void rt6_purge_dflt_routers(struct net *net) 4408 { 4409 struct fib6_table *table; 4410 struct hlist_head *head; 4411 unsigned int h; 4412 4413 rcu_read_lock(); 4414 4415 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { 4416 head = &net->ipv6.fib_table_hash[h]; 4417 hlist_for_each_entry_rcu(table, head, tb6_hlist) { 4418 if (table->flags & RT6_TABLE_HAS_DFLT_ROUTER) 4419 __rt6_purge_dflt_routers(net, table); 4420 } 4421 } 4422 4423 rcu_read_unlock(); 4424 } 4425 4426 static void rtmsg_to_fib6_config(struct net *net, 4427 struct in6_rtmsg *rtmsg, 4428 struct fib6_config *cfg) 4429 { 4430 *cfg = (struct fib6_config){ 4431 .fc_table = l3mdev_fib_table_by_index(net, rtmsg->rtmsg_ifindex) ? 4432 : RT6_TABLE_MAIN, 4433 .fc_ifindex = rtmsg->rtmsg_ifindex, 4434 .fc_metric = rtmsg->rtmsg_metric ? : IP6_RT_PRIO_USER, 4435 .fc_expires = rtmsg->rtmsg_info, 4436 .fc_dst_len = rtmsg->rtmsg_dst_len, 4437 .fc_src_len = rtmsg->rtmsg_src_len, 4438 .fc_flags = rtmsg->rtmsg_flags, 4439 .fc_type = rtmsg->rtmsg_type, 4440 4441 .fc_nlinfo.nl_net = net, 4442 4443 .fc_dst = rtmsg->rtmsg_dst, 4444 .fc_src = rtmsg->rtmsg_src, 4445 .fc_gateway = rtmsg->rtmsg_gateway, 4446 }; 4447 } 4448 4449 int ipv6_route_ioctl(struct net *net, unsigned int cmd, struct in6_rtmsg *rtmsg) 4450 { 4451 struct fib6_config cfg; 4452 int err; 4453 4454 if (cmd != SIOCADDRT && cmd != SIOCDELRT) 4455 return -EINVAL; 4456 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 4457 return -EPERM; 4458 4459 rtmsg_to_fib6_config(net, rtmsg, &cfg); 4460 4461 rtnl_lock(); 4462 switch (cmd) { 4463 case SIOCADDRT: 4464 err = ip6_route_add(&cfg, GFP_KERNEL, NULL); 4465 break; 4466 case SIOCDELRT: 4467 err = ip6_route_del(&cfg, NULL); 4468 break; 4469 } 4470 rtnl_unlock(); 4471 return err; 4472 } 4473 4474 /* 4475 * Drop the packet on the floor 4476 */ 4477 4478 static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes) 4479 { 4480 struct dst_entry *dst = skb_dst(skb); 4481 struct net *net = dev_net(dst->dev); 4482 struct inet6_dev *idev; 4483 SKB_DR(reason); 4484 int type; 4485 4486 if (netif_is_l3_master(skb->dev) || 4487 dst->dev == net->loopback_dev) 4488 idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif)); 4489 else 4490 idev = ip6_dst_idev(dst); 4491 4492 switch (ipstats_mib_noroutes) { 4493 case IPSTATS_MIB_INNOROUTES: 4494 type = ipv6_addr_type(&ipv6_hdr(skb)->daddr); 4495 if (type == IPV6_ADDR_ANY) { 4496 SKB_DR_SET(reason, IP_INADDRERRORS); 4497 IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); 4498 break; 4499 } 4500 SKB_DR_SET(reason, IP_INNOROUTES); 4501 fallthrough; 4502 case IPSTATS_MIB_OUTNOROUTES: 4503 SKB_DR_OR(reason, IP_OUTNOROUTES); 4504 IP6_INC_STATS(net, idev, ipstats_mib_noroutes); 4505 break; 4506 } 4507 4508 /* Start over by dropping the dst for l3mdev case */ 4509 if (netif_is_l3_master(skb->dev)) 4510 skb_dst_drop(skb); 4511 4512 icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0); 4513 kfree_skb_reason(skb, reason); 4514 return 0; 4515 } 4516 4517 static int ip6_pkt_discard(struct sk_buff *skb) 4518 { 4519 return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES); 4520 } 4521 4522 static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb) 4523 { 4524 skb->dev = skb_dst(skb)->dev; 4525 return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES); 4526 } 4527 4528 static int ip6_pkt_prohibit(struct sk_buff *skb) 4529 { 4530 return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES); 4531 } 4532 4533 static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb) 4534 { 4535 skb->dev = skb_dst(skb)->dev; 4536 return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES); 4537 } 4538 4539 /* 4540 * Allocate a dst for local (unicast / anycast) address. 4541 */ 4542 4543 struct fib6_info *addrconf_f6i_alloc(struct net *net, 4544 struct inet6_dev *idev, 4545 const struct in6_addr *addr, 4546 bool anycast, gfp_t gfp_flags, 4547 struct netlink_ext_ack *extack) 4548 { 4549 struct fib6_config cfg = { 4550 .fc_table = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL, 4551 .fc_ifindex = idev->dev->ifindex, 4552 .fc_flags = RTF_UP | RTF_NONEXTHOP, 4553 .fc_dst = *addr, 4554 .fc_dst_len = 128, 4555 .fc_protocol = RTPROT_KERNEL, 4556 .fc_nlinfo.nl_net = net, 4557 .fc_ignore_dev_down = true, 4558 }; 4559 struct fib6_info *f6i; 4560 4561 if (anycast) { 4562 cfg.fc_type = RTN_ANYCAST; 4563 cfg.fc_flags |= RTF_ANYCAST; 4564 } else { 4565 cfg.fc_type = RTN_LOCAL; 4566 cfg.fc_flags |= RTF_LOCAL; 4567 } 4568 4569 f6i = ip6_route_info_create(&cfg, gfp_flags, extack); 4570 if (!IS_ERR(f6i)) { 4571 f6i->dst_nocount = true; 4572 4573 if (!anycast && 4574 (net->ipv6.devconf_all->disable_policy || 4575 idev->cnf.disable_policy)) 4576 f6i->dst_nopolicy = true; 4577 } 4578 4579 return f6i; 4580 } 4581 4582 /* remove deleted ip from prefsrc entries */ 4583 struct arg_dev_net_ip { 4584 struct net *net; 4585 struct in6_addr *addr; 4586 }; 4587 4588 static int fib6_remove_prefsrc(struct fib6_info *rt, void *arg) 4589 { 4590 struct net *net = ((struct arg_dev_net_ip *)arg)->net; 4591 struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr; 4592 4593 if (!rt->nh && 4594 rt != net->ipv6.fib6_null_entry && 4595 ipv6_addr_equal(addr, &rt->fib6_prefsrc.addr) && 4596 !ipv6_chk_addr(net, addr, rt->fib6_nh->fib_nh_dev, 0)) { 4597 spin_lock_bh(&rt6_exception_lock); 4598 /* remove prefsrc entry */ 4599 rt->fib6_prefsrc.plen = 0; 4600 spin_unlock_bh(&rt6_exception_lock); 4601 } 4602 return 0; 4603 } 4604 4605 void rt6_remove_prefsrc(struct inet6_ifaddr *ifp) 4606 { 4607 struct net *net = dev_net(ifp->idev->dev); 4608 struct arg_dev_net_ip adni = { 4609 .net = net, 4610 .addr = &ifp->addr, 4611 }; 4612 fib6_clean_all(net, fib6_remove_prefsrc, &adni); 4613 } 4614 4615 #define RTF_RA_ROUTER (RTF_ADDRCONF | RTF_DEFAULT) 4616 4617 /* Remove routers and update dst entries when gateway turn into host. */ 4618 static int fib6_clean_tohost(struct fib6_info *rt, void *arg) 4619 { 4620 struct in6_addr *gateway = (struct in6_addr *)arg; 4621 struct fib6_nh *nh; 4622 4623 /* RA routes do not use nexthops */ 4624 if (rt->nh) 4625 return 0; 4626 4627 nh = rt->fib6_nh; 4628 if (((rt->fib6_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) && 4629 nh->fib_nh_gw_family && ipv6_addr_equal(gateway, &nh->fib_nh_gw6)) 4630 return -1; 4631 4632 /* Further clean up cached routes in exception table. 4633 * This is needed because cached route may have a different 4634 * gateway than its 'parent' in the case of an ip redirect. 4635 */ 4636 fib6_nh_exceptions_clean_tohost(nh, gateway); 4637 4638 return 0; 4639 } 4640 4641 void rt6_clean_tohost(struct net *net, struct in6_addr *gateway) 4642 { 4643 fib6_clean_all(net, fib6_clean_tohost, gateway); 4644 } 4645 4646 struct arg_netdev_event { 4647 const struct net_device *dev; 4648 union { 4649 unsigned char nh_flags; 4650 unsigned long event; 4651 }; 4652 }; 4653 4654 static struct fib6_info *rt6_multipath_first_sibling(const struct fib6_info *rt) 4655 { 4656 struct fib6_info *iter; 4657 struct fib6_node *fn; 4658 4659 fn = rcu_dereference_protected(rt->fib6_node, 4660 lockdep_is_held(&rt->fib6_table->tb6_lock)); 4661 iter = rcu_dereference_protected(fn->leaf, 4662 lockdep_is_held(&rt->fib6_table->tb6_lock)); 4663 while (iter) { 4664 if (iter->fib6_metric == rt->fib6_metric && 4665 rt6_qualify_for_ecmp(iter)) 4666 return iter; 4667 iter = rcu_dereference_protected(iter->fib6_next, 4668 lockdep_is_held(&rt->fib6_table->tb6_lock)); 4669 } 4670 4671 return NULL; 4672 } 4673 4674 /* only called for fib entries with builtin fib6_nh */ 4675 static bool rt6_is_dead(const struct fib6_info *rt) 4676 { 4677 if (rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD || 4678 (rt->fib6_nh->fib_nh_flags & RTNH_F_LINKDOWN && 4679 ip6_ignore_linkdown(rt->fib6_nh->fib_nh_dev))) 4680 return true; 4681 4682 return false; 4683 } 4684 4685 static int rt6_multipath_total_weight(const struct fib6_info *rt) 4686 { 4687 struct fib6_info *iter; 4688 int total = 0; 4689 4690 if (!rt6_is_dead(rt)) 4691 total += rt->fib6_nh->fib_nh_weight; 4692 4693 list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) { 4694 if (!rt6_is_dead(iter)) 4695 total += iter->fib6_nh->fib_nh_weight; 4696 } 4697 4698 return total; 4699 } 4700 4701 static void rt6_upper_bound_set(struct fib6_info *rt, int *weight, int total) 4702 { 4703 int upper_bound = -1; 4704 4705 if (!rt6_is_dead(rt)) { 4706 *weight += rt->fib6_nh->fib_nh_weight; 4707 upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31, 4708 total) - 1; 4709 } 4710 atomic_set(&rt->fib6_nh->fib_nh_upper_bound, upper_bound); 4711 } 4712 4713 static void rt6_multipath_upper_bound_set(struct fib6_info *rt, int total) 4714 { 4715 struct fib6_info *iter; 4716 int weight = 0; 4717 4718 rt6_upper_bound_set(rt, &weight, total); 4719 4720 list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) 4721 rt6_upper_bound_set(iter, &weight, total); 4722 } 4723 4724 void rt6_multipath_rebalance(struct fib6_info *rt) 4725 { 4726 struct fib6_info *first; 4727 int total; 4728 4729 /* In case the entire multipath route was marked for flushing, 4730 * then there is no need to rebalance upon the removal of every 4731 * sibling route. 4732 */ 4733 if (!rt->fib6_nsiblings || rt->should_flush) 4734 return; 4735 4736 /* During lookup routes are evaluated in order, so we need to 4737 * make sure upper bounds are assigned from the first sibling 4738 * onwards. 4739 */ 4740 first = rt6_multipath_first_sibling(rt); 4741 if (WARN_ON_ONCE(!first)) 4742 return; 4743 4744 total = rt6_multipath_total_weight(first); 4745 rt6_multipath_upper_bound_set(first, total); 4746 } 4747 4748 static int fib6_ifup(struct fib6_info *rt, void *p_arg) 4749 { 4750 const struct arg_netdev_event *arg = p_arg; 4751 struct net *net = dev_net(arg->dev); 4752 4753 if (rt != net->ipv6.fib6_null_entry && !rt->nh && 4754 rt->fib6_nh->fib_nh_dev == arg->dev) { 4755 rt->fib6_nh->fib_nh_flags &= ~arg->nh_flags; 4756 fib6_update_sernum_upto_root(net, rt); 4757 rt6_multipath_rebalance(rt); 4758 } 4759 4760 return 0; 4761 } 4762 4763 void rt6_sync_up(struct net_device *dev, unsigned char nh_flags) 4764 { 4765 struct arg_netdev_event arg = { 4766 .dev = dev, 4767 { 4768 .nh_flags = nh_flags, 4769 }, 4770 }; 4771 4772 if (nh_flags & RTNH_F_DEAD && netif_carrier_ok(dev)) 4773 arg.nh_flags |= RTNH_F_LINKDOWN; 4774 4775 fib6_clean_all(dev_net(dev), fib6_ifup, &arg); 4776 } 4777 4778 /* only called for fib entries with inline fib6_nh */ 4779 static bool rt6_multipath_uses_dev(const struct fib6_info *rt, 4780 const struct net_device *dev) 4781 { 4782 struct fib6_info *iter; 4783 4784 if (rt->fib6_nh->fib_nh_dev == dev) 4785 return true; 4786 list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) 4787 if (iter->fib6_nh->fib_nh_dev == dev) 4788 return true; 4789 4790 return false; 4791 } 4792 4793 static void rt6_multipath_flush(struct fib6_info *rt) 4794 { 4795 struct fib6_info *iter; 4796 4797 rt->should_flush = 1; 4798 list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) 4799 iter->should_flush = 1; 4800 } 4801 4802 static unsigned int rt6_multipath_dead_count(const struct fib6_info *rt, 4803 const struct net_device *down_dev) 4804 { 4805 struct fib6_info *iter; 4806 unsigned int dead = 0; 4807 4808 if (rt->fib6_nh->fib_nh_dev == down_dev || 4809 rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD) 4810 dead++; 4811 list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) 4812 if (iter->fib6_nh->fib_nh_dev == down_dev || 4813 iter->fib6_nh->fib_nh_flags & RTNH_F_DEAD) 4814 dead++; 4815 4816 return dead; 4817 } 4818 4819 static void rt6_multipath_nh_flags_set(struct fib6_info *rt, 4820 const struct net_device *dev, 4821 unsigned char nh_flags) 4822 { 4823 struct fib6_info *iter; 4824 4825 if (rt->fib6_nh->fib_nh_dev == dev) 4826 rt->fib6_nh->fib_nh_flags |= nh_flags; 4827 list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) 4828 if (iter->fib6_nh->fib_nh_dev == dev) 4829 iter->fib6_nh->fib_nh_flags |= nh_flags; 4830 } 4831 4832 /* called with write lock held for table with rt */ 4833 static int fib6_ifdown(struct fib6_info *rt, void *p_arg) 4834 { 4835 const struct arg_netdev_event *arg = p_arg; 4836 const struct net_device *dev = arg->dev; 4837 struct net *net = dev_net(dev); 4838 4839 if (rt == net->ipv6.fib6_null_entry || rt->nh) 4840 return 0; 4841 4842 switch (arg->event) { 4843 case NETDEV_UNREGISTER: 4844 return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0; 4845 case NETDEV_DOWN: 4846 if (rt->should_flush) 4847 return -1; 4848 if (!rt->fib6_nsiblings) 4849 return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0; 4850 if (rt6_multipath_uses_dev(rt, dev)) { 4851 unsigned int count; 4852 4853 count = rt6_multipath_dead_count(rt, dev); 4854 if (rt->fib6_nsiblings + 1 == count) { 4855 rt6_multipath_flush(rt); 4856 return -1; 4857 } 4858 rt6_multipath_nh_flags_set(rt, dev, RTNH_F_DEAD | 4859 RTNH_F_LINKDOWN); 4860 fib6_update_sernum(net, rt); 4861 rt6_multipath_rebalance(rt); 4862 } 4863 return -2; 4864 case NETDEV_CHANGE: 4865 if (rt->fib6_nh->fib_nh_dev != dev || 4866 rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) 4867 break; 4868 rt->fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN; 4869 rt6_multipath_rebalance(rt); 4870 break; 4871 } 4872 4873 return 0; 4874 } 4875 4876 void rt6_sync_down_dev(struct net_device *dev, unsigned long event) 4877 { 4878 struct arg_netdev_event arg = { 4879 .dev = dev, 4880 { 4881 .event = event, 4882 }, 4883 }; 4884 struct net *net = dev_net(dev); 4885 4886 if (net->ipv6.sysctl.skip_notify_on_dev_down) 4887 fib6_clean_all_skip_notify(net, fib6_ifdown, &arg); 4888 else 4889 fib6_clean_all(net, fib6_ifdown, &arg); 4890 } 4891 4892 void rt6_disable_ip(struct net_device *dev, unsigned long event) 4893 { 4894 rt6_sync_down_dev(dev, event); 4895 rt6_uncached_list_flush_dev(dev); 4896 neigh_ifdown(&nd_tbl, dev); 4897 } 4898 4899 struct rt6_mtu_change_arg { 4900 struct net_device *dev; 4901 unsigned int mtu; 4902 struct fib6_info *f6i; 4903 }; 4904 4905 static int fib6_nh_mtu_change(struct fib6_nh *nh, void *_arg) 4906 { 4907 struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *)_arg; 4908 struct fib6_info *f6i = arg->f6i; 4909 4910 /* For administrative MTU increase, there is no way to discover 4911 * IPv6 PMTU increase, so PMTU increase should be updated here. 4912 * Since RFC 1981 doesn't include administrative MTU increase 4913 * update PMTU increase is a MUST. (i.e. jumbo frame) 4914 */ 4915 if (nh->fib_nh_dev == arg->dev) { 4916 struct inet6_dev *idev = __in6_dev_get(arg->dev); 4917 u32 mtu = f6i->fib6_pmtu; 4918 4919 if (mtu >= arg->mtu || 4920 (mtu < arg->mtu && mtu == idev->cnf.mtu6)) 4921 fib6_metric_set(f6i, RTAX_MTU, arg->mtu); 4922 4923 spin_lock_bh(&rt6_exception_lock); 4924 rt6_exceptions_update_pmtu(idev, nh, arg->mtu); 4925 spin_unlock_bh(&rt6_exception_lock); 4926 } 4927 4928 return 0; 4929 } 4930 4931 static int rt6_mtu_change_route(struct fib6_info *f6i, void *p_arg) 4932 { 4933 struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg; 4934 struct inet6_dev *idev; 4935 4936 /* In IPv6 pmtu discovery is not optional, 4937 so that RTAX_MTU lock cannot disable it. 4938 We still use this lock to block changes 4939 caused by addrconf/ndisc. 4940 */ 4941 4942 idev = __in6_dev_get(arg->dev); 4943 if (!idev) 4944 return 0; 4945 4946 if (fib6_metric_locked(f6i, RTAX_MTU)) 4947 return 0; 4948 4949 arg->f6i = f6i; 4950 if (f6i->nh) { 4951 /* fib6_nh_mtu_change only returns 0, so this is safe */ 4952 return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_mtu_change, 4953 arg); 4954 } 4955 4956 return fib6_nh_mtu_change(f6i->fib6_nh, arg); 4957 } 4958 4959 void rt6_mtu_change(struct net_device *dev, unsigned int mtu) 4960 { 4961 struct rt6_mtu_change_arg arg = { 4962 .dev = dev, 4963 .mtu = mtu, 4964 }; 4965 4966 fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg); 4967 } 4968 4969 static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = { 4970 [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 }, 4971 [RTA_GATEWAY] = { .len = sizeof(struct in6_addr) }, 4972 [RTA_PREFSRC] = { .len = sizeof(struct in6_addr) }, 4973 [RTA_OIF] = { .type = NLA_U32 }, 4974 [RTA_IIF] = { .type = NLA_U32 }, 4975 [RTA_PRIORITY] = { .type = NLA_U32 }, 4976 [RTA_METRICS] = { .type = NLA_NESTED }, 4977 [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, 4978 [RTA_PREF] = { .type = NLA_U8 }, 4979 [RTA_ENCAP_TYPE] = { .type = NLA_U16 }, 4980 [RTA_ENCAP] = { .type = NLA_NESTED }, 4981 [RTA_EXPIRES] = { .type = NLA_U32 }, 4982 [RTA_UID] = { .type = NLA_U32 }, 4983 [RTA_MARK] = { .type = NLA_U32 }, 4984 [RTA_TABLE] = { .type = NLA_U32 }, 4985 [RTA_IP_PROTO] = { .type = NLA_U8 }, 4986 [RTA_SPORT] = { .type = NLA_U16 }, 4987 [RTA_DPORT] = { .type = NLA_U16 }, 4988 [RTA_NH_ID] = { .type = NLA_U32 }, 4989 }; 4990 4991 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh, 4992 struct fib6_config *cfg, 4993 struct netlink_ext_ack *extack) 4994 { 4995 struct rtmsg *rtm; 4996 struct nlattr *tb[RTA_MAX+1]; 4997 unsigned int pref; 4998 int err; 4999 5000 err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 5001 rtm_ipv6_policy, extack); 5002 if (err < 0) 5003 goto errout; 5004 5005 err = -EINVAL; 5006 rtm = nlmsg_data(nlh); 5007 5008 if (rtm->rtm_tos) { 5009 NL_SET_ERR_MSG(extack, 5010 "Invalid dsfield (tos): option not available for IPv6"); 5011 goto errout; 5012 } 5013 5014 *cfg = (struct fib6_config){ 5015 .fc_table = rtm->rtm_table, 5016 .fc_dst_len = rtm->rtm_dst_len, 5017 .fc_src_len = rtm->rtm_src_len, 5018 .fc_flags = RTF_UP, 5019 .fc_protocol = rtm->rtm_protocol, 5020 .fc_type = rtm->rtm_type, 5021 5022 .fc_nlinfo.portid = NETLINK_CB(skb).portid, 5023 .fc_nlinfo.nlh = nlh, 5024 .fc_nlinfo.nl_net = sock_net(skb->sk), 5025 }; 5026 5027 if (rtm->rtm_type == RTN_UNREACHABLE || 5028 rtm->rtm_type == RTN_BLACKHOLE || 5029 rtm->rtm_type == RTN_PROHIBIT || 5030 rtm->rtm_type == RTN_THROW) 5031 cfg->fc_flags |= RTF_REJECT; 5032 5033 if (rtm->rtm_type == RTN_LOCAL) 5034 cfg->fc_flags |= RTF_LOCAL; 5035 5036 if (rtm->rtm_flags & RTM_F_CLONED) 5037 cfg->fc_flags |= RTF_CACHE; 5038 5039 cfg->fc_flags |= (rtm->rtm_flags & RTNH_F_ONLINK); 5040 5041 if (tb[RTA_NH_ID]) { 5042 if (tb[RTA_GATEWAY] || tb[RTA_OIF] || 5043 tb[RTA_MULTIPATH] || tb[RTA_ENCAP]) { 5044 NL_SET_ERR_MSG(extack, 5045 "Nexthop specification and nexthop id are mutually exclusive"); 5046 goto errout; 5047 } 5048 cfg->fc_nh_id = nla_get_u32(tb[RTA_NH_ID]); 5049 } 5050 5051 if (tb[RTA_GATEWAY]) { 5052 cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]); 5053 cfg->fc_flags |= RTF_GATEWAY; 5054 } 5055 if (tb[RTA_VIA]) { 5056 NL_SET_ERR_MSG(extack, "IPv6 does not support RTA_VIA attribute"); 5057 goto errout; 5058 } 5059 5060 if (tb[RTA_DST]) { 5061 int plen = (rtm->rtm_dst_len + 7) >> 3; 5062 5063 if (nla_len(tb[RTA_DST]) < plen) 5064 goto errout; 5065 5066 nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen); 5067 } 5068 5069 if (tb[RTA_SRC]) { 5070 int plen = (rtm->rtm_src_len + 7) >> 3; 5071 5072 if (nla_len(tb[RTA_SRC]) < plen) 5073 goto errout; 5074 5075 nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen); 5076 } 5077 5078 if (tb[RTA_PREFSRC]) 5079 cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]); 5080 5081 if (tb[RTA_OIF]) 5082 cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]); 5083 5084 if (tb[RTA_PRIORITY]) 5085 cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]); 5086 5087 if (tb[RTA_METRICS]) { 5088 cfg->fc_mx = nla_data(tb[RTA_METRICS]); 5089 cfg->fc_mx_len = nla_len(tb[RTA_METRICS]); 5090 } 5091 5092 if (tb[RTA_TABLE]) 5093 cfg->fc_table = nla_get_u32(tb[RTA_TABLE]); 5094 5095 if (tb[RTA_MULTIPATH]) { 5096 cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]); 5097 cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]); 5098 5099 err = lwtunnel_valid_encap_type_attr(cfg->fc_mp, 5100 cfg->fc_mp_len, extack); 5101 if (err < 0) 5102 goto errout; 5103 } 5104 5105 if (tb[RTA_PREF]) { 5106 pref = nla_get_u8(tb[RTA_PREF]); 5107 if (pref != ICMPV6_ROUTER_PREF_LOW && 5108 pref != ICMPV6_ROUTER_PREF_HIGH) 5109 pref = ICMPV6_ROUTER_PREF_MEDIUM; 5110 cfg->fc_flags |= RTF_PREF(pref); 5111 } 5112 5113 if (tb[RTA_ENCAP]) 5114 cfg->fc_encap = tb[RTA_ENCAP]; 5115 5116 if (tb[RTA_ENCAP_TYPE]) { 5117 cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]); 5118 5119 err = lwtunnel_valid_encap_type(cfg->fc_encap_type, extack); 5120 if (err < 0) 5121 goto errout; 5122 } 5123 5124 if (tb[RTA_EXPIRES]) { 5125 unsigned long timeout = addrconf_timeout_fixup(nla_get_u32(tb[RTA_EXPIRES]), HZ); 5126 5127 if (addrconf_finite_timeout(timeout)) { 5128 cfg->fc_expires = jiffies_to_clock_t(timeout * HZ); 5129 cfg->fc_flags |= RTF_EXPIRES; 5130 } 5131 } 5132 5133 err = 0; 5134 errout: 5135 return err; 5136 } 5137 5138 struct rt6_nh { 5139 struct fib6_info *fib6_info; 5140 struct fib6_config r_cfg; 5141 struct list_head next; 5142 }; 5143 5144 static int ip6_route_info_append(struct net *net, 5145 struct list_head *rt6_nh_list, 5146 struct fib6_info *rt, 5147 struct fib6_config *r_cfg) 5148 { 5149 struct rt6_nh *nh; 5150 int err = -EEXIST; 5151 5152 list_for_each_entry(nh, rt6_nh_list, next) { 5153 /* check if fib6_info already exists */ 5154 if (rt6_duplicate_nexthop(nh->fib6_info, rt)) 5155 return err; 5156 } 5157 5158 nh = kzalloc(sizeof(*nh), GFP_KERNEL); 5159 if (!nh) 5160 return -ENOMEM; 5161 nh->fib6_info = rt; 5162 memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg)); 5163 list_add_tail(&nh->next, rt6_nh_list); 5164 5165 return 0; 5166 } 5167 5168 static void ip6_route_mpath_notify(struct fib6_info *rt, 5169 struct fib6_info *rt_last, 5170 struct nl_info *info, 5171 __u16 nlflags) 5172 { 5173 /* if this is an APPEND route, then rt points to the first route 5174 * inserted and rt_last points to last route inserted. Userspace 5175 * wants a consistent dump of the route which starts at the first 5176 * nexthop. Since sibling routes are always added at the end of 5177 * the list, find the first sibling of the last route appended 5178 */ 5179 if ((nlflags & NLM_F_APPEND) && rt_last && rt_last->fib6_nsiblings) { 5180 rt = list_first_entry(&rt_last->fib6_siblings, 5181 struct fib6_info, 5182 fib6_siblings); 5183 } 5184 5185 if (rt) 5186 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags); 5187 } 5188 5189 static bool ip6_route_mpath_should_notify(const struct fib6_info *rt) 5190 { 5191 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); 5192 bool should_notify = false; 5193 struct fib6_info *leaf; 5194 struct fib6_node *fn; 5195 5196 rcu_read_lock(); 5197 fn = rcu_dereference(rt->fib6_node); 5198 if (!fn) 5199 goto out; 5200 5201 leaf = rcu_dereference(fn->leaf); 5202 if (!leaf) 5203 goto out; 5204 5205 if (rt == leaf || 5206 (rt_can_ecmp && rt->fib6_metric == leaf->fib6_metric && 5207 rt6_qualify_for_ecmp(leaf))) 5208 should_notify = true; 5209 out: 5210 rcu_read_unlock(); 5211 5212 return should_notify; 5213 } 5214 5215 static int fib6_gw_from_attr(struct in6_addr *gw, struct nlattr *nla, 5216 struct netlink_ext_ack *extack) 5217 { 5218 if (nla_len(nla) < sizeof(*gw)) { 5219 NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_GATEWAY"); 5220 return -EINVAL; 5221 } 5222 5223 *gw = nla_get_in6_addr(nla); 5224 5225 return 0; 5226 } 5227 5228 static int ip6_route_multipath_add(struct fib6_config *cfg, 5229 struct netlink_ext_ack *extack) 5230 { 5231 struct fib6_info *rt_notif = NULL, *rt_last = NULL; 5232 struct nl_info *info = &cfg->fc_nlinfo; 5233 struct fib6_config r_cfg; 5234 struct rtnexthop *rtnh; 5235 struct fib6_info *rt; 5236 struct rt6_nh *err_nh; 5237 struct rt6_nh *nh, *nh_safe; 5238 __u16 nlflags; 5239 int remaining; 5240 int attrlen; 5241 int err = 1; 5242 int nhn = 0; 5243 int replace = (cfg->fc_nlinfo.nlh && 5244 (cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE)); 5245 LIST_HEAD(rt6_nh_list); 5246 5247 nlflags = replace ? NLM_F_REPLACE : NLM_F_CREATE; 5248 if (info->nlh && info->nlh->nlmsg_flags & NLM_F_APPEND) 5249 nlflags |= NLM_F_APPEND; 5250 5251 remaining = cfg->fc_mp_len; 5252 rtnh = (struct rtnexthop *)cfg->fc_mp; 5253 5254 /* Parse a Multipath Entry and build a list (rt6_nh_list) of 5255 * fib6_info structs per nexthop 5256 */ 5257 while (rtnh_ok(rtnh, remaining)) { 5258 memcpy(&r_cfg, cfg, sizeof(*cfg)); 5259 if (rtnh->rtnh_ifindex) 5260 r_cfg.fc_ifindex = rtnh->rtnh_ifindex; 5261 5262 attrlen = rtnh_attrlen(rtnh); 5263 if (attrlen > 0) { 5264 struct nlattr *nla, *attrs = rtnh_attrs(rtnh); 5265 5266 nla = nla_find(attrs, attrlen, RTA_GATEWAY); 5267 if (nla) { 5268 err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla, 5269 extack); 5270 if (err) 5271 goto cleanup; 5272 5273 r_cfg.fc_flags |= RTF_GATEWAY; 5274 } 5275 r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP); 5276 5277 /* RTA_ENCAP_TYPE length checked in 5278 * lwtunnel_valid_encap_type_attr 5279 */ 5280 nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE); 5281 if (nla) 5282 r_cfg.fc_encap_type = nla_get_u16(nla); 5283 } 5284 5285 r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK); 5286 rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack); 5287 if (IS_ERR(rt)) { 5288 err = PTR_ERR(rt); 5289 rt = NULL; 5290 goto cleanup; 5291 } 5292 if (!rt6_qualify_for_ecmp(rt)) { 5293 err = -EINVAL; 5294 NL_SET_ERR_MSG(extack, 5295 "Device only routes can not be added for IPv6 using the multipath API."); 5296 fib6_info_release(rt); 5297 goto cleanup; 5298 } 5299 5300 rt->fib6_nh->fib_nh_weight = rtnh->rtnh_hops + 1; 5301 5302 err = ip6_route_info_append(info->nl_net, &rt6_nh_list, 5303 rt, &r_cfg); 5304 if (err) { 5305 fib6_info_release(rt); 5306 goto cleanup; 5307 } 5308 5309 rtnh = rtnh_next(rtnh, &remaining); 5310 } 5311 5312 if (list_empty(&rt6_nh_list)) { 5313 NL_SET_ERR_MSG(extack, 5314 "Invalid nexthop configuration - no valid nexthops"); 5315 return -EINVAL; 5316 } 5317 5318 /* for add and replace send one notification with all nexthops. 5319 * Skip the notification in fib6_add_rt2node and send one with 5320 * the full route when done 5321 */ 5322 info->skip_notify = 1; 5323 5324 /* For add and replace, send one notification with all nexthops. For 5325 * append, send one notification with all appended nexthops. 5326 */ 5327 info->skip_notify_kernel = 1; 5328 5329 err_nh = NULL; 5330 list_for_each_entry(nh, &rt6_nh_list, next) { 5331 err = __ip6_ins_rt(nh->fib6_info, info, extack); 5332 fib6_info_release(nh->fib6_info); 5333 5334 if (!err) { 5335 /* save reference to last route successfully inserted */ 5336 rt_last = nh->fib6_info; 5337 5338 /* save reference to first route for notification */ 5339 if (!rt_notif) 5340 rt_notif = nh->fib6_info; 5341 } 5342 5343 /* nh->fib6_info is used or freed at this point, reset to NULL*/ 5344 nh->fib6_info = NULL; 5345 if (err) { 5346 if (replace && nhn) 5347 NL_SET_ERR_MSG_MOD(extack, 5348 "multipath route replace failed (check consistency of installed routes)"); 5349 err_nh = nh; 5350 goto add_errout; 5351 } 5352 5353 /* Because each route is added like a single route we remove 5354 * these flags after the first nexthop: if there is a collision, 5355 * we have already failed to add the first nexthop: 5356 * fib6_add_rt2node() has rejected it; when replacing, old 5357 * nexthops have been replaced by first new, the rest should 5358 * be added to it. 5359 */ 5360 if (cfg->fc_nlinfo.nlh) { 5361 cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL | 5362 NLM_F_REPLACE); 5363 cfg->fc_nlinfo.nlh->nlmsg_flags |= NLM_F_CREATE; 5364 } 5365 nhn++; 5366 } 5367 5368 /* An in-kernel notification should only be sent in case the new 5369 * multipath route is added as the first route in the node, or if 5370 * it was appended to it. We pass 'rt_notif' since it is the first 5371 * sibling and might allow us to skip some checks in the replace case. 5372 */ 5373 if (ip6_route_mpath_should_notify(rt_notif)) { 5374 enum fib_event_type fib_event; 5375 5376 if (rt_notif->fib6_nsiblings != nhn - 1) 5377 fib_event = FIB_EVENT_ENTRY_APPEND; 5378 else 5379 fib_event = FIB_EVENT_ENTRY_REPLACE; 5380 5381 err = call_fib6_multipath_entry_notifiers(info->nl_net, 5382 fib_event, rt_notif, 5383 nhn - 1, extack); 5384 if (err) { 5385 /* Delete all the siblings that were just added */ 5386 err_nh = NULL; 5387 goto add_errout; 5388 } 5389 } 5390 5391 /* success ... tell user about new route */ 5392 ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags); 5393 goto cleanup; 5394 5395 add_errout: 5396 /* send notification for routes that were added so that 5397 * the delete notifications sent by ip6_route_del are 5398 * coherent 5399 */ 5400 if (rt_notif) 5401 ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags); 5402 5403 /* Delete routes that were already added */ 5404 list_for_each_entry(nh, &rt6_nh_list, next) { 5405 if (err_nh == nh) 5406 break; 5407 ip6_route_del(&nh->r_cfg, extack); 5408 } 5409 5410 cleanup: 5411 list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) { 5412 if (nh->fib6_info) 5413 fib6_info_release(nh->fib6_info); 5414 list_del(&nh->next); 5415 kfree(nh); 5416 } 5417 5418 return err; 5419 } 5420 5421 static int ip6_route_multipath_del(struct fib6_config *cfg, 5422 struct netlink_ext_ack *extack) 5423 { 5424 struct fib6_config r_cfg; 5425 struct rtnexthop *rtnh; 5426 int last_err = 0; 5427 int remaining; 5428 int attrlen; 5429 int err; 5430 5431 remaining = cfg->fc_mp_len; 5432 rtnh = (struct rtnexthop *)cfg->fc_mp; 5433 5434 /* Parse a Multipath Entry */ 5435 while (rtnh_ok(rtnh, remaining)) { 5436 memcpy(&r_cfg, cfg, sizeof(*cfg)); 5437 if (rtnh->rtnh_ifindex) 5438 r_cfg.fc_ifindex = rtnh->rtnh_ifindex; 5439 5440 attrlen = rtnh_attrlen(rtnh); 5441 if (attrlen > 0) { 5442 struct nlattr *nla, *attrs = rtnh_attrs(rtnh); 5443 5444 nla = nla_find(attrs, attrlen, RTA_GATEWAY); 5445 if (nla) { 5446 err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla, 5447 extack); 5448 if (err) { 5449 last_err = err; 5450 goto next_rtnh; 5451 } 5452 5453 r_cfg.fc_flags |= RTF_GATEWAY; 5454 } 5455 } 5456 err = ip6_route_del(&r_cfg, extack); 5457 if (err) 5458 last_err = err; 5459 5460 next_rtnh: 5461 rtnh = rtnh_next(rtnh, &remaining); 5462 } 5463 5464 return last_err; 5465 } 5466 5467 static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, 5468 struct netlink_ext_ack *extack) 5469 { 5470 struct fib6_config cfg; 5471 int err; 5472 5473 err = rtm_to_fib6_config(skb, nlh, &cfg, extack); 5474 if (err < 0) 5475 return err; 5476 5477 if (cfg.fc_nh_id && 5478 !nexthop_find_by_id(sock_net(skb->sk), cfg.fc_nh_id)) { 5479 NL_SET_ERR_MSG(extack, "Nexthop id does not exist"); 5480 return -EINVAL; 5481 } 5482 5483 if (cfg.fc_mp) 5484 return ip6_route_multipath_del(&cfg, extack); 5485 else { 5486 cfg.fc_delete_all_nh = 1; 5487 return ip6_route_del(&cfg, extack); 5488 } 5489 } 5490 5491 static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, 5492 struct netlink_ext_ack *extack) 5493 { 5494 struct fib6_config cfg; 5495 int err; 5496 5497 err = rtm_to_fib6_config(skb, nlh, &cfg, extack); 5498 if (err < 0) 5499 return err; 5500 5501 if (cfg.fc_metric == 0) 5502 cfg.fc_metric = IP6_RT_PRIO_USER; 5503 5504 if (cfg.fc_mp) 5505 return ip6_route_multipath_add(&cfg, extack); 5506 else 5507 return ip6_route_add(&cfg, GFP_KERNEL, extack); 5508 } 5509 5510 /* add the overhead of this fib6_nh to nexthop_len */ 5511 static int rt6_nh_nlmsg_size(struct fib6_nh *nh, void *arg) 5512 { 5513 int *nexthop_len = arg; 5514 5515 *nexthop_len += nla_total_size(0) /* RTA_MULTIPATH */ 5516 + NLA_ALIGN(sizeof(struct rtnexthop)) 5517 + nla_total_size(16); /* RTA_GATEWAY */ 5518 5519 if (nh->fib_nh_lws) { 5520 /* RTA_ENCAP_TYPE */ 5521 *nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws); 5522 /* RTA_ENCAP */ 5523 *nexthop_len += nla_total_size(2); 5524 } 5525 5526 return 0; 5527 } 5528 5529 static size_t rt6_nlmsg_size(struct fib6_info *f6i) 5530 { 5531 int nexthop_len; 5532 5533 if (f6i->nh) { 5534 nexthop_len = nla_total_size(4); /* RTA_NH_ID */ 5535 nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_nlmsg_size, 5536 &nexthop_len); 5537 } else { 5538 struct fib6_info *sibling, *next_sibling; 5539 struct fib6_nh *nh = f6i->fib6_nh; 5540 5541 nexthop_len = 0; 5542 if (f6i->fib6_nsiblings) { 5543 rt6_nh_nlmsg_size(nh, &nexthop_len); 5544 5545 list_for_each_entry_safe(sibling, next_sibling, 5546 &f6i->fib6_siblings, fib6_siblings) { 5547 rt6_nh_nlmsg_size(sibling->fib6_nh, &nexthop_len); 5548 } 5549 } 5550 nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws); 5551 } 5552 5553 return NLMSG_ALIGN(sizeof(struct rtmsg)) 5554 + nla_total_size(16) /* RTA_SRC */ 5555 + nla_total_size(16) /* RTA_DST */ 5556 + nla_total_size(16) /* RTA_GATEWAY */ 5557 + nla_total_size(16) /* RTA_PREFSRC */ 5558 + nla_total_size(4) /* RTA_TABLE */ 5559 + nla_total_size(4) /* RTA_IIF */ 5560 + nla_total_size(4) /* RTA_OIF */ 5561 + nla_total_size(4) /* RTA_PRIORITY */ 5562 + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */ 5563 + nla_total_size(sizeof(struct rta_cacheinfo)) 5564 + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */ 5565 + nla_total_size(1) /* RTA_PREF */ 5566 + nexthop_len; 5567 } 5568 5569 static int rt6_fill_node_nexthop(struct sk_buff *skb, struct nexthop *nh, 5570 unsigned char *flags) 5571 { 5572 if (nexthop_is_multipath(nh)) { 5573 struct nlattr *mp; 5574 5575 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH); 5576 if (!mp) 5577 goto nla_put_failure; 5578 5579 if (nexthop_mpath_fill_node(skb, nh, AF_INET6)) 5580 goto nla_put_failure; 5581 5582 nla_nest_end(skb, mp); 5583 } else { 5584 struct fib6_nh *fib6_nh; 5585 5586 fib6_nh = nexthop_fib6_nh(nh); 5587 if (fib_nexthop_info(skb, &fib6_nh->nh_common, AF_INET6, 5588 flags, false) < 0) 5589 goto nla_put_failure; 5590 } 5591 5592 return 0; 5593 5594 nla_put_failure: 5595 return -EMSGSIZE; 5596 } 5597 5598 static int rt6_fill_node(struct net *net, struct sk_buff *skb, 5599 struct fib6_info *rt, struct dst_entry *dst, 5600 struct in6_addr *dest, struct in6_addr *src, 5601 int iif, int type, u32 portid, u32 seq, 5602 unsigned int flags) 5603 { 5604 struct rt6_info *rt6 = (struct rt6_info *)dst; 5605 struct rt6key *rt6_dst, *rt6_src; 5606 u32 *pmetrics, table, rt6_flags; 5607 unsigned char nh_flags = 0; 5608 struct nlmsghdr *nlh; 5609 struct rtmsg *rtm; 5610 long expires = 0; 5611 5612 nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags); 5613 if (!nlh) 5614 return -EMSGSIZE; 5615 5616 if (rt6) { 5617 rt6_dst = &rt6->rt6i_dst; 5618 rt6_src = &rt6->rt6i_src; 5619 rt6_flags = rt6->rt6i_flags; 5620 } else { 5621 rt6_dst = &rt->fib6_dst; 5622 rt6_src = &rt->fib6_src; 5623 rt6_flags = rt->fib6_flags; 5624 } 5625 5626 rtm = nlmsg_data(nlh); 5627 rtm->rtm_family = AF_INET6; 5628 rtm->rtm_dst_len = rt6_dst->plen; 5629 rtm->rtm_src_len = rt6_src->plen; 5630 rtm->rtm_tos = 0; 5631 if (rt->fib6_table) 5632 table = rt->fib6_table->tb6_id; 5633 else 5634 table = RT6_TABLE_UNSPEC; 5635 rtm->rtm_table = table < 256 ? table : RT_TABLE_COMPAT; 5636 if (nla_put_u32(skb, RTA_TABLE, table)) 5637 goto nla_put_failure; 5638 5639 rtm->rtm_type = rt->fib6_type; 5640 rtm->rtm_flags = 0; 5641 rtm->rtm_scope = RT_SCOPE_UNIVERSE; 5642 rtm->rtm_protocol = rt->fib6_protocol; 5643 5644 if (rt6_flags & RTF_CACHE) 5645 rtm->rtm_flags |= RTM_F_CLONED; 5646 5647 if (dest) { 5648 if (nla_put_in6_addr(skb, RTA_DST, dest)) 5649 goto nla_put_failure; 5650 rtm->rtm_dst_len = 128; 5651 } else if (rtm->rtm_dst_len) 5652 if (nla_put_in6_addr(skb, RTA_DST, &rt6_dst->addr)) 5653 goto nla_put_failure; 5654 #ifdef CONFIG_IPV6_SUBTREES 5655 if (src) { 5656 if (nla_put_in6_addr(skb, RTA_SRC, src)) 5657 goto nla_put_failure; 5658 rtm->rtm_src_len = 128; 5659 } else if (rtm->rtm_src_len && 5660 nla_put_in6_addr(skb, RTA_SRC, &rt6_src->addr)) 5661 goto nla_put_failure; 5662 #endif 5663 if (iif) { 5664 #ifdef CONFIG_IPV6_MROUTE 5665 if (ipv6_addr_is_multicast(&rt6_dst->addr)) { 5666 int err = ip6mr_get_route(net, skb, rtm, portid); 5667 5668 if (err == 0) 5669 return 0; 5670 if (err < 0) 5671 goto nla_put_failure; 5672 } else 5673 #endif 5674 if (nla_put_u32(skb, RTA_IIF, iif)) 5675 goto nla_put_failure; 5676 } else if (dest) { 5677 struct in6_addr saddr_buf; 5678 if (ip6_route_get_saddr(net, rt, dest, 0, &saddr_buf) == 0 && 5679 nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf)) 5680 goto nla_put_failure; 5681 } 5682 5683 if (rt->fib6_prefsrc.plen) { 5684 struct in6_addr saddr_buf; 5685 saddr_buf = rt->fib6_prefsrc.addr; 5686 if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf)) 5687 goto nla_put_failure; 5688 } 5689 5690 pmetrics = dst ? dst_metrics_ptr(dst) : rt->fib6_metrics->metrics; 5691 if (rtnetlink_put_metrics(skb, pmetrics) < 0) 5692 goto nla_put_failure; 5693 5694 if (nla_put_u32(skb, RTA_PRIORITY, rt->fib6_metric)) 5695 goto nla_put_failure; 5696 5697 /* For multipath routes, walk the siblings list and add 5698 * each as a nexthop within RTA_MULTIPATH. 5699 */ 5700 if (rt6) { 5701 if (rt6_flags & RTF_GATEWAY && 5702 nla_put_in6_addr(skb, RTA_GATEWAY, &rt6->rt6i_gateway)) 5703 goto nla_put_failure; 5704 5705 if (dst->dev && nla_put_u32(skb, RTA_OIF, dst->dev->ifindex)) 5706 goto nla_put_failure; 5707 5708 if (dst->lwtstate && 5709 lwtunnel_fill_encap(skb, dst->lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0) 5710 goto nla_put_failure; 5711 } else if (rt->fib6_nsiblings) { 5712 struct fib6_info *sibling, *next_sibling; 5713 struct nlattr *mp; 5714 5715 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH); 5716 if (!mp) 5717 goto nla_put_failure; 5718 5719 if (fib_add_nexthop(skb, &rt->fib6_nh->nh_common, 5720 rt->fib6_nh->fib_nh_weight, AF_INET6, 5721 0) < 0) 5722 goto nla_put_failure; 5723 5724 list_for_each_entry_safe(sibling, next_sibling, 5725 &rt->fib6_siblings, fib6_siblings) { 5726 if (fib_add_nexthop(skb, &sibling->fib6_nh->nh_common, 5727 sibling->fib6_nh->fib_nh_weight, 5728 AF_INET6, 0) < 0) 5729 goto nla_put_failure; 5730 } 5731 5732 nla_nest_end(skb, mp); 5733 } else if (rt->nh) { 5734 if (nla_put_u32(skb, RTA_NH_ID, rt->nh->id)) 5735 goto nla_put_failure; 5736 5737 if (nexthop_is_blackhole(rt->nh)) 5738 rtm->rtm_type = RTN_BLACKHOLE; 5739 5740 if (READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode) && 5741 rt6_fill_node_nexthop(skb, rt->nh, &nh_flags) < 0) 5742 goto nla_put_failure; 5743 5744 rtm->rtm_flags |= nh_flags; 5745 } else { 5746 if (fib_nexthop_info(skb, &rt->fib6_nh->nh_common, AF_INET6, 5747 &nh_flags, false) < 0) 5748 goto nla_put_failure; 5749 5750 rtm->rtm_flags |= nh_flags; 5751 } 5752 5753 if (rt6_flags & RTF_EXPIRES) { 5754 expires = dst ? dst->expires : rt->expires; 5755 expires -= jiffies; 5756 } 5757 5758 if (!dst) { 5759 if (READ_ONCE(rt->offload)) 5760 rtm->rtm_flags |= RTM_F_OFFLOAD; 5761 if (READ_ONCE(rt->trap)) 5762 rtm->rtm_flags |= RTM_F_TRAP; 5763 if (READ_ONCE(rt->offload_failed)) 5764 rtm->rtm_flags |= RTM_F_OFFLOAD_FAILED; 5765 } 5766 5767 if (rtnl_put_cacheinfo(skb, dst, 0, expires, dst ? dst->error : 0) < 0) 5768 goto nla_put_failure; 5769 5770 if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt6_flags))) 5771 goto nla_put_failure; 5772 5773 5774 nlmsg_end(skb, nlh); 5775 return 0; 5776 5777 nla_put_failure: 5778 nlmsg_cancel(skb, nlh); 5779 return -EMSGSIZE; 5780 } 5781 5782 static int fib6_info_nh_uses_dev(struct fib6_nh *nh, void *arg) 5783 { 5784 const struct net_device *dev = arg; 5785 5786 if (nh->fib_nh_dev == dev) 5787 return 1; 5788 5789 return 0; 5790 } 5791 5792 static bool fib6_info_uses_dev(const struct fib6_info *f6i, 5793 const struct net_device *dev) 5794 { 5795 if (f6i->nh) { 5796 struct net_device *_dev = (struct net_device *)dev; 5797 5798 return !!nexthop_for_each_fib6_nh(f6i->nh, 5799 fib6_info_nh_uses_dev, 5800 _dev); 5801 } 5802 5803 if (f6i->fib6_nh->fib_nh_dev == dev) 5804 return true; 5805 5806 if (f6i->fib6_nsiblings) { 5807 struct fib6_info *sibling, *next_sibling; 5808 5809 list_for_each_entry_safe(sibling, next_sibling, 5810 &f6i->fib6_siblings, fib6_siblings) { 5811 if (sibling->fib6_nh->fib_nh_dev == dev) 5812 return true; 5813 } 5814 } 5815 5816 return false; 5817 } 5818 5819 struct fib6_nh_exception_dump_walker { 5820 struct rt6_rtnl_dump_arg *dump; 5821 struct fib6_info *rt; 5822 unsigned int flags; 5823 unsigned int skip; 5824 unsigned int count; 5825 }; 5826 5827 static int rt6_nh_dump_exceptions(struct fib6_nh *nh, void *arg) 5828 { 5829 struct fib6_nh_exception_dump_walker *w = arg; 5830 struct rt6_rtnl_dump_arg *dump = w->dump; 5831 struct rt6_exception_bucket *bucket; 5832 struct rt6_exception *rt6_ex; 5833 int i, err; 5834 5835 bucket = fib6_nh_get_excptn_bucket(nh, NULL); 5836 if (!bucket) 5837 return 0; 5838 5839 for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) { 5840 hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) { 5841 if (w->skip) { 5842 w->skip--; 5843 continue; 5844 } 5845 5846 /* Expiration of entries doesn't bump sernum, insertion 5847 * does. Removal is triggered by insertion, so we can 5848 * rely on the fact that if entries change between two 5849 * partial dumps, this node is scanned again completely, 5850 * see rt6_insert_exception() and fib6_dump_table(). 5851 * 5852 * Count expired entries we go through as handled 5853 * entries that we'll skip next time, in case of partial 5854 * node dump. Otherwise, if entries expire meanwhile, 5855 * we'll skip the wrong amount. 5856 */ 5857 if (rt6_check_expired(rt6_ex->rt6i)) { 5858 w->count++; 5859 continue; 5860 } 5861 5862 err = rt6_fill_node(dump->net, dump->skb, w->rt, 5863 &rt6_ex->rt6i->dst, NULL, NULL, 0, 5864 RTM_NEWROUTE, 5865 NETLINK_CB(dump->cb->skb).portid, 5866 dump->cb->nlh->nlmsg_seq, w->flags); 5867 if (err) 5868 return err; 5869 5870 w->count++; 5871 } 5872 bucket++; 5873 } 5874 5875 return 0; 5876 } 5877 5878 /* Return -1 if done with node, number of handled routes on partial dump */ 5879 int rt6_dump_route(struct fib6_info *rt, void *p_arg, unsigned int skip) 5880 { 5881 struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg; 5882 struct fib_dump_filter *filter = &arg->filter; 5883 unsigned int flags = NLM_F_MULTI; 5884 struct net *net = arg->net; 5885 int count = 0; 5886 5887 if (rt == net->ipv6.fib6_null_entry) 5888 return -1; 5889 5890 if ((filter->flags & RTM_F_PREFIX) && 5891 !(rt->fib6_flags & RTF_PREFIX_RT)) { 5892 /* success since this is not a prefix route */ 5893 return -1; 5894 } 5895 if (filter->filter_set && 5896 ((filter->rt_type && rt->fib6_type != filter->rt_type) || 5897 (filter->dev && !fib6_info_uses_dev(rt, filter->dev)) || 5898 (filter->protocol && rt->fib6_protocol != filter->protocol))) { 5899 return -1; 5900 } 5901 5902 if (filter->filter_set || 5903 !filter->dump_routes || !filter->dump_exceptions) { 5904 flags |= NLM_F_DUMP_FILTERED; 5905 } 5906 5907 if (filter->dump_routes) { 5908 if (skip) { 5909 skip--; 5910 } else { 5911 if (rt6_fill_node(net, arg->skb, rt, NULL, NULL, NULL, 5912 0, RTM_NEWROUTE, 5913 NETLINK_CB(arg->cb->skb).portid, 5914 arg->cb->nlh->nlmsg_seq, flags)) { 5915 return 0; 5916 } 5917 count++; 5918 } 5919 } 5920 5921 if (filter->dump_exceptions) { 5922 struct fib6_nh_exception_dump_walker w = { .dump = arg, 5923 .rt = rt, 5924 .flags = flags, 5925 .skip = skip, 5926 .count = 0 }; 5927 int err; 5928 5929 rcu_read_lock(); 5930 if (rt->nh) { 5931 err = nexthop_for_each_fib6_nh(rt->nh, 5932 rt6_nh_dump_exceptions, 5933 &w); 5934 } else { 5935 err = rt6_nh_dump_exceptions(rt->fib6_nh, &w); 5936 } 5937 rcu_read_unlock(); 5938 5939 if (err) 5940 return count + w.count; 5941 } 5942 5943 return -1; 5944 } 5945 5946 static int inet6_rtm_valid_getroute_req(struct sk_buff *skb, 5947 const struct nlmsghdr *nlh, 5948 struct nlattr **tb, 5949 struct netlink_ext_ack *extack) 5950 { 5951 struct rtmsg *rtm; 5952 int i, err; 5953 5954 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { 5955 NL_SET_ERR_MSG_MOD(extack, 5956 "Invalid header for get route request"); 5957 return -EINVAL; 5958 } 5959 5960 if (!netlink_strict_get_check(skb)) 5961 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, 5962 rtm_ipv6_policy, extack); 5963 5964 rtm = nlmsg_data(nlh); 5965 if ((rtm->rtm_src_len && rtm->rtm_src_len != 128) || 5966 (rtm->rtm_dst_len && rtm->rtm_dst_len != 128) || 5967 rtm->rtm_table || rtm->rtm_protocol || rtm->rtm_scope || 5968 rtm->rtm_type) { 5969 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request"); 5970 return -EINVAL; 5971 } 5972 if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) { 5973 NL_SET_ERR_MSG_MOD(extack, 5974 "Invalid flags for get route request"); 5975 return -EINVAL; 5976 } 5977 5978 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, 5979 rtm_ipv6_policy, extack); 5980 if (err) 5981 return err; 5982 5983 if ((tb[RTA_SRC] && !rtm->rtm_src_len) || 5984 (tb[RTA_DST] && !rtm->rtm_dst_len)) { 5985 NL_SET_ERR_MSG_MOD(extack, "rtm_src_len and rtm_dst_len must be 128 for IPv6"); 5986 return -EINVAL; 5987 } 5988 5989 for (i = 0; i <= RTA_MAX; i++) { 5990 if (!tb[i]) 5991 continue; 5992 5993 switch (i) { 5994 case RTA_SRC: 5995 case RTA_DST: 5996 case RTA_IIF: 5997 case RTA_OIF: 5998 case RTA_MARK: 5999 case RTA_UID: 6000 case RTA_SPORT: 6001 case RTA_DPORT: 6002 case RTA_IP_PROTO: 6003 break; 6004 default: 6005 NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request"); 6006 return -EINVAL; 6007 } 6008 } 6009 6010 return 0; 6011 } 6012 6013 static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, 6014 struct netlink_ext_ack *extack) 6015 { 6016 struct net *net = sock_net(in_skb->sk); 6017 struct nlattr *tb[RTA_MAX+1]; 6018 int err, iif = 0, oif = 0; 6019 struct fib6_info *from; 6020 struct dst_entry *dst; 6021 struct rt6_info *rt; 6022 struct sk_buff *skb; 6023 struct rtmsg *rtm; 6024 struct flowi6 fl6 = {}; 6025 bool fibmatch; 6026 6027 err = inet6_rtm_valid_getroute_req(in_skb, nlh, tb, extack); 6028 if (err < 0) 6029 goto errout; 6030 6031 err = -EINVAL; 6032 rtm = nlmsg_data(nlh); 6033 fl6.flowlabel = ip6_make_flowinfo(rtm->rtm_tos, 0); 6034 fibmatch = !!(rtm->rtm_flags & RTM_F_FIB_MATCH); 6035 6036 if (tb[RTA_SRC]) { 6037 if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr)) 6038 goto errout; 6039 6040 fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]); 6041 } 6042 6043 if (tb[RTA_DST]) { 6044 if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr)) 6045 goto errout; 6046 6047 fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]); 6048 } 6049 6050 if (tb[RTA_IIF]) 6051 iif = nla_get_u32(tb[RTA_IIF]); 6052 6053 if (tb[RTA_OIF]) 6054 oif = nla_get_u32(tb[RTA_OIF]); 6055 6056 if (tb[RTA_MARK]) 6057 fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]); 6058 6059 if (tb[RTA_UID]) 6060 fl6.flowi6_uid = make_kuid(current_user_ns(), 6061 nla_get_u32(tb[RTA_UID])); 6062 else 6063 fl6.flowi6_uid = iif ? INVALID_UID : current_uid(); 6064 6065 if (tb[RTA_SPORT]) 6066 fl6.fl6_sport = nla_get_be16(tb[RTA_SPORT]); 6067 6068 if (tb[RTA_DPORT]) 6069 fl6.fl6_dport = nla_get_be16(tb[RTA_DPORT]); 6070 6071 if (tb[RTA_IP_PROTO]) { 6072 err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], 6073 &fl6.flowi6_proto, AF_INET6, 6074 extack); 6075 if (err) 6076 goto errout; 6077 } 6078 6079 if (iif) { 6080 struct net_device *dev; 6081 int flags = 0; 6082 6083 rcu_read_lock(); 6084 6085 dev = dev_get_by_index_rcu(net, iif); 6086 if (!dev) { 6087 rcu_read_unlock(); 6088 err = -ENODEV; 6089 goto errout; 6090 } 6091 6092 fl6.flowi6_iif = iif; 6093 6094 if (!ipv6_addr_any(&fl6.saddr)) 6095 flags |= RT6_LOOKUP_F_HAS_SADDR; 6096 6097 dst = ip6_route_input_lookup(net, dev, &fl6, NULL, flags); 6098 6099 rcu_read_unlock(); 6100 } else { 6101 fl6.flowi6_oif = oif; 6102 6103 dst = ip6_route_output(net, NULL, &fl6); 6104 } 6105 6106 6107 rt = container_of(dst, struct rt6_info, dst); 6108 if (rt->dst.error) { 6109 err = rt->dst.error; 6110 ip6_rt_put(rt); 6111 goto errout; 6112 } 6113 6114 if (rt == net->ipv6.ip6_null_entry) { 6115 err = rt->dst.error; 6116 ip6_rt_put(rt); 6117 goto errout; 6118 } 6119 6120 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); 6121 if (!skb) { 6122 ip6_rt_put(rt); 6123 err = -ENOBUFS; 6124 goto errout; 6125 } 6126 6127 skb_dst_set(skb, &rt->dst); 6128 6129 rcu_read_lock(); 6130 from = rcu_dereference(rt->from); 6131 if (from) { 6132 if (fibmatch) 6133 err = rt6_fill_node(net, skb, from, NULL, NULL, NULL, 6134 iif, RTM_NEWROUTE, 6135 NETLINK_CB(in_skb).portid, 6136 nlh->nlmsg_seq, 0); 6137 else 6138 err = rt6_fill_node(net, skb, from, dst, &fl6.daddr, 6139 &fl6.saddr, iif, RTM_NEWROUTE, 6140 NETLINK_CB(in_skb).portid, 6141 nlh->nlmsg_seq, 0); 6142 } else { 6143 err = -ENETUNREACH; 6144 } 6145 rcu_read_unlock(); 6146 6147 if (err < 0) { 6148 kfree_skb(skb); 6149 goto errout; 6150 } 6151 6152 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); 6153 errout: 6154 return err; 6155 } 6156 6157 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info, 6158 unsigned int nlm_flags) 6159 { 6160 struct sk_buff *skb; 6161 struct net *net = info->nl_net; 6162 u32 seq; 6163 int err; 6164 6165 err = -ENOBUFS; 6166 seq = info->nlh ? info->nlh->nlmsg_seq : 0; 6167 6168 skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any()); 6169 if (!skb) 6170 goto errout; 6171 6172 err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0, 6173 event, info->portid, seq, nlm_flags); 6174 if (err < 0) { 6175 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */ 6176 WARN_ON(err == -EMSGSIZE); 6177 kfree_skb(skb); 6178 goto errout; 6179 } 6180 rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE, 6181 info->nlh, gfp_any()); 6182 return; 6183 errout: 6184 if (err < 0) 6185 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err); 6186 } 6187 6188 void fib6_rt_update(struct net *net, struct fib6_info *rt, 6189 struct nl_info *info) 6190 { 6191 u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; 6192 struct sk_buff *skb; 6193 int err = -ENOBUFS; 6194 6195 skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any()); 6196 if (!skb) 6197 goto errout; 6198 6199 err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0, 6200 RTM_NEWROUTE, info->portid, seq, NLM_F_REPLACE); 6201 if (err < 0) { 6202 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */ 6203 WARN_ON(err == -EMSGSIZE); 6204 kfree_skb(skb); 6205 goto errout; 6206 } 6207 rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE, 6208 info->nlh, gfp_any()); 6209 return; 6210 errout: 6211 if (err < 0) 6212 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err); 6213 } 6214 6215 void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i, 6216 bool offload, bool trap, bool offload_failed) 6217 { 6218 struct sk_buff *skb; 6219 int err; 6220 6221 if (READ_ONCE(f6i->offload) == offload && 6222 READ_ONCE(f6i->trap) == trap && 6223 READ_ONCE(f6i->offload_failed) == offload_failed) 6224 return; 6225 6226 WRITE_ONCE(f6i->offload, offload); 6227 WRITE_ONCE(f6i->trap, trap); 6228 6229 /* 2 means send notifications only if offload_failed was changed. */ 6230 if (net->ipv6.sysctl.fib_notify_on_flag_change == 2 && 6231 READ_ONCE(f6i->offload_failed) == offload_failed) 6232 return; 6233 6234 WRITE_ONCE(f6i->offload_failed, offload_failed); 6235 6236 if (!rcu_access_pointer(f6i->fib6_node)) 6237 /* The route was removed from the tree, do not send 6238 * notification. 6239 */ 6240 return; 6241 6242 if (!net->ipv6.sysctl.fib_notify_on_flag_change) 6243 return; 6244 6245 skb = nlmsg_new(rt6_nlmsg_size(f6i), GFP_KERNEL); 6246 if (!skb) { 6247 err = -ENOBUFS; 6248 goto errout; 6249 } 6250 6251 err = rt6_fill_node(net, skb, f6i, NULL, NULL, NULL, 0, RTM_NEWROUTE, 0, 6252 0, 0); 6253 if (err < 0) { 6254 /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */ 6255 WARN_ON(err == -EMSGSIZE); 6256 kfree_skb(skb); 6257 goto errout; 6258 } 6259 6260 rtnl_notify(skb, net, 0, RTNLGRP_IPV6_ROUTE, NULL, GFP_KERNEL); 6261 return; 6262 6263 errout: 6264 rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err); 6265 } 6266 EXPORT_SYMBOL(fib6_info_hw_flags_set); 6267 6268 static int ip6_route_dev_notify(struct notifier_block *this, 6269 unsigned long event, void *ptr) 6270 { 6271 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 6272 struct net *net = dev_net(dev); 6273 6274 if (!(dev->flags & IFF_LOOPBACK)) 6275 return NOTIFY_OK; 6276 6277 if (event == NETDEV_REGISTER) { 6278 net->ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = dev; 6279 net->ipv6.ip6_null_entry->dst.dev = dev; 6280 net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev); 6281 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 6282 net->ipv6.ip6_prohibit_entry->dst.dev = dev; 6283 net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev); 6284 net->ipv6.ip6_blk_hole_entry->dst.dev = dev; 6285 net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev); 6286 #endif 6287 } else if (event == NETDEV_UNREGISTER && 6288 dev->reg_state != NETREG_UNREGISTERED) { 6289 /* NETDEV_UNREGISTER could be fired for multiple times by 6290 * netdev_wait_allrefs(). Make sure we only call this once. 6291 */ 6292 in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev); 6293 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 6294 in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev); 6295 in6_dev_put_clear(&net->ipv6.ip6_blk_hole_entry->rt6i_idev); 6296 #endif 6297 } 6298 6299 return NOTIFY_OK; 6300 } 6301 6302 /* 6303 * /proc 6304 */ 6305 6306 #ifdef CONFIG_PROC_FS 6307 static int rt6_stats_seq_show(struct seq_file *seq, void *v) 6308 { 6309 struct net *net = (struct net *)seq->private; 6310 seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n", 6311 net->ipv6.rt6_stats->fib_nodes, 6312 net->ipv6.rt6_stats->fib_route_nodes, 6313 atomic_read(&net->ipv6.rt6_stats->fib_rt_alloc), 6314 net->ipv6.rt6_stats->fib_rt_entries, 6315 net->ipv6.rt6_stats->fib_rt_cache, 6316 dst_entries_get_slow(&net->ipv6.ip6_dst_ops), 6317 net->ipv6.rt6_stats->fib_discarded_routes); 6318 6319 return 0; 6320 } 6321 #endif /* CONFIG_PROC_FS */ 6322 6323 #ifdef CONFIG_SYSCTL 6324 6325 static int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write, 6326 void *buffer, size_t *lenp, loff_t *ppos) 6327 { 6328 struct net *net; 6329 int delay; 6330 int ret; 6331 if (!write) 6332 return -EINVAL; 6333 6334 net = (struct net *)ctl->extra1; 6335 delay = net->ipv6.sysctl.flush_delay; 6336 ret = proc_dointvec(ctl, write, buffer, lenp, ppos); 6337 if (ret) 6338 return ret; 6339 6340 fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0); 6341 return 0; 6342 } 6343 6344 static struct ctl_table ipv6_route_table_template[] = { 6345 { 6346 .procname = "max_size", 6347 .data = &init_net.ipv6.sysctl.ip6_rt_max_size, 6348 .maxlen = sizeof(int), 6349 .mode = 0644, 6350 .proc_handler = proc_dointvec, 6351 }, 6352 { 6353 .procname = "gc_thresh", 6354 .data = &ip6_dst_ops_template.gc_thresh, 6355 .maxlen = sizeof(int), 6356 .mode = 0644, 6357 .proc_handler = proc_dointvec, 6358 }, 6359 { 6360 .procname = "flush", 6361 .data = &init_net.ipv6.sysctl.flush_delay, 6362 .maxlen = sizeof(int), 6363 .mode = 0200, 6364 .proc_handler = ipv6_sysctl_rtcache_flush 6365 }, 6366 { 6367 .procname = "gc_min_interval", 6368 .data = &init_net.ipv6.sysctl.ip6_rt_gc_min_interval, 6369 .maxlen = sizeof(int), 6370 .mode = 0644, 6371 .proc_handler = proc_dointvec_jiffies, 6372 }, 6373 { 6374 .procname = "gc_timeout", 6375 .data = &init_net.ipv6.sysctl.ip6_rt_gc_timeout, 6376 .maxlen = sizeof(int), 6377 .mode = 0644, 6378 .proc_handler = proc_dointvec_jiffies, 6379 }, 6380 { 6381 .procname = "gc_interval", 6382 .data = &init_net.ipv6.sysctl.ip6_rt_gc_interval, 6383 .maxlen = sizeof(int), 6384 .mode = 0644, 6385 .proc_handler = proc_dointvec_jiffies, 6386 }, 6387 { 6388 .procname = "gc_elasticity", 6389 .data = &init_net.ipv6.sysctl.ip6_rt_gc_elasticity, 6390 .maxlen = sizeof(int), 6391 .mode = 0644, 6392 .proc_handler = proc_dointvec, 6393 }, 6394 { 6395 .procname = "mtu_expires", 6396 .data = &init_net.ipv6.sysctl.ip6_rt_mtu_expires, 6397 .maxlen = sizeof(int), 6398 .mode = 0644, 6399 .proc_handler = proc_dointvec_jiffies, 6400 }, 6401 { 6402 .procname = "min_adv_mss", 6403 .data = &init_net.ipv6.sysctl.ip6_rt_min_advmss, 6404 .maxlen = sizeof(int), 6405 .mode = 0644, 6406 .proc_handler = proc_dointvec, 6407 }, 6408 { 6409 .procname = "gc_min_interval_ms", 6410 .data = &init_net.ipv6.sysctl.ip6_rt_gc_min_interval, 6411 .maxlen = sizeof(int), 6412 .mode = 0644, 6413 .proc_handler = proc_dointvec_ms_jiffies, 6414 }, 6415 { 6416 .procname = "skip_notify_on_dev_down", 6417 .data = &init_net.ipv6.sysctl.skip_notify_on_dev_down, 6418 .maxlen = sizeof(u8), 6419 .mode = 0644, 6420 .proc_handler = proc_dou8vec_minmax, 6421 .extra1 = SYSCTL_ZERO, 6422 .extra2 = SYSCTL_ONE, 6423 }, 6424 { } 6425 }; 6426 6427 struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net) 6428 { 6429 struct ctl_table *table; 6430 6431 table = kmemdup(ipv6_route_table_template, 6432 sizeof(ipv6_route_table_template), 6433 GFP_KERNEL); 6434 6435 if (table) { 6436 table[0].data = &net->ipv6.sysctl.ip6_rt_max_size; 6437 table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh; 6438 table[2].data = &net->ipv6.sysctl.flush_delay; 6439 table[2].extra1 = net; 6440 table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval; 6441 table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout; 6442 table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval; 6443 table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity; 6444 table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires; 6445 table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss; 6446 table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval; 6447 table[10].data = &net->ipv6.sysctl.skip_notify_on_dev_down; 6448 6449 /* Don't export sysctls to unprivileged users */ 6450 if (net->user_ns != &init_user_ns) 6451 table[1].procname = NULL; 6452 } 6453 6454 return table; 6455 } 6456 6457 size_t ipv6_route_sysctl_table_size(struct net *net) 6458 { 6459 /* Don't export sysctls to unprivileged users */ 6460 if (net->user_ns != &init_user_ns) 6461 return 1; 6462 6463 return ARRAY_SIZE(ipv6_route_table_template); 6464 } 6465 #endif 6466 6467 static int __net_init ip6_route_net_init(struct net *net) 6468 { 6469 int ret = -ENOMEM; 6470 6471 memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template, 6472 sizeof(net->ipv6.ip6_dst_ops)); 6473 6474 if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0) 6475 goto out_ip6_dst_ops; 6476 6477 net->ipv6.fib6_null_entry = fib6_info_alloc(GFP_KERNEL, true); 6478 if (!net->ipv6.fib6_null_entry) 6479 goto out_ip6_dst_entries; 6480 memcpy(net->ipv6.fib6_null_entry, &fib6_null_entry_template, 6481 sizeof(*net->ipv6.fib6_null_entry)); 6482 6483 net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template, 6484 sizeof(*net->ipv6.ip6_null_entry), 6485 GFP_KERNEL); 6486 if (!net->ipv6.ip6_null_entry) 6487 goto out_fib6_null_entry; 6488 net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops; 6489 dst_init_metrics(&net->ipv6.ip6_null_entry->dst, 6490 ip6_template_metrics, true); 6491 INIT_LIST_HEAD(&net->ipv6.ip6_null_entry->dst.rt_uncached); 6492 6493 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 6494 net->ipv6.fib6_has_custom_rules = false; 6495 net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template, 6496 sizeof(*net->ipv6.ip6_prohibit_entry), 6497 GFP_KERNEL); 6498 if (!net->ipv6.ip6_prohibit_entry) 6499 goto out_ip6_null_entry; 6500 net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops; 6501 dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst, 6502 ip6_template_metrics, true); 6503 INIT_LIST_HEAD(&net->ipv6.ip6_prohibit_entry->dst.rt_uncached); 6504 6505 net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template, 6506 sizeof(*net->ipv6.ip6_blk_hole_entry), 6507 GFP_KERNEL); 6508 if (!net->ipv6.ip6_blk_hole_entry) 6509 goto out_ip6_prohibit_entry; 6510 net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops; 6511 dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst, 6512 ip6_template_metrics, true); 6513 INIT_LIST_HEAD(&net->ipv6.ip6_blk_hole_entry->dst.rt_uncached); 6514 #ifdef CONFIG_IPV6_SUBTREES 6515 net->ipv6.fib6_routes_require_src = 0; 6516 #endif 6517 #endif 6518 6519 net->ipv6.sysctl.flush_delay = 0; 6520 net->ipv6.sysctl.ip6_rt_max_size = INT_MAX; 6521 net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2; 6522 net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ; 6523 net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ; 6524 net->ipv6.sysctl.ip6_rt_gc_elasticity = 9; 6525 net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ; 6526 net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40; 6527 net->ipv6.sysctl.skip_notify_on_dev_down = 0; 6528 6529 atomic_set(&net->ipv6.ip6_rt_gc_expire, 30*HZ); 6530 6531 ret = 0; 6532 out: 6533 return ret; 6534 6535 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 6536 out_ip6_prohibit_entry: 6537 kfree(net->ipv6.ip6_prohibit_entry); 6538 out_ip6_null_entry: 6539 kfree(net->ipv6.ip6_null_entry); 6540 #endif 6541 out_fib6_null_entry: 6542 kfree(net->ipv6.fib6_null_entry); 6543 out_ip6_dst_entries: 6544 dst_entries_destroy(&net->ipv6.ip6_dst_ops); 6545 out_ip6_dst_ops: 6546 goto out; 6547 } 6548 6549 static void __net_exit ip6_route_net_exit(struct net *net) 6550 { 6551 kfree(net->ipv6.fib6_null_entry); 6552 kfree(net->ipv6.ip6_null_entry); 6553 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 6554 kfree(net->ipv6.ip6_prohibit_entry); 6555 kfree(net->ipv6.ip6_blk_hole_entry); 6556 #endif 6557 dst_entries_destroy(&net->ipv6.ip6_dst_ops); 6558 } 6559 6560 static int __net_init ip6_route_net_init_late(struct net *net) 6561 { 6562 #ifdef CONFIG_PROC_FS 6563 if (!proc_create_net("ipv6_route", 0, net->proc_net, 6564 &ipv6_route_seq_ops, 6565 sizeof(struct ipv6_route_iter))) 6566 return -ENOMEM; 6567 6568 if (!proc_create_net_single("rt6_stats", 0444, net->proc_net, 6569 rt6_stats_seq_show, NULL)) { 6570 remove_proc_entry("ipv6_route", net->proc_net); 6571 return -ENOMEM; 6572 } 6573 #endif 6574 return 0; 6575 } 6576 6577 static void __net_exit ip6_route_net_exit_late(struct net *net) 6578 { 6579 #ifdef CONFIG_PROC_FS 6580 remove_proc_entry("ipv6_route", net->proc_net); 6581 remove_proc_entry("rt6_stats", net->proc_net); 6582 #endif 6583 } 6584 6585 static struct pernet_operations ip6_route_net_ops = { 6586 .init = ip6_route_net_init, 6587 .exit = ip6_route_net_exit, 6588 }; 6589 6590 static int __net_init ipv6_inetpeer_init(struct net *net) 6591 { 6592 struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); 6593 6594 if (!bp) 6595 return -ENOMEM; 6596 inet_peer_base_init(bp); 6597 net->ipv6.peers = bp; 6598 return 0; 6599 } 6600 6601 static void __net_exit ipv6_inetpeer_exit(struct net *net) 6602 { 6603 struct inet_peer_base *bp = net->ipv6.peers; 6604 6605 net->ipv6.peers = NULL; 6606 inetpeer_invalidate_tree(bp); 6607 kfree(bp); 6608 } 6609 6610 static struct pernet_operations ipv6_inetpeer_ops = { 6611 .init = ipv6_inetpeer_init, 6612 .exit = ipv6_inetpeer_exit, 6613 }; 6614 6615 static struct pernet_operations ip6_route_net_late_ops = { 6616 .init = ip6_route_net_init_late, 6617 .exit = ip6_route_net_exit_late, 6618 }; 6619 6620 static struct notifier_block ip6_route_dev_notifier = { 6621 .notifier_call = ip6_route_dev_notify, 6622 .priority = ADDRCONF_NOTIFY_PRIORITY - 10, 6623 }; 6624 6625 void __init ip6_route_init_special_entries(void) 6626 { 6627 /* Registering of the loopback is done before this portion of code, 6628 * the loopback reference in rt6_info will not be taken, do it 6629 * manually for init_net */ 6630 init_net.ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = init_net.loopback_dev; 6631 init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev; 6632 init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev); 6633 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 6634 init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev; 6635 init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev); 6636 init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev; 6637 init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev); 6638 #endif 6639 } 6640 6641 #if IS_BUILTIN(CONFIG_IPV6) 6642 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) 6643 DEFINE_BPF_ITER_FUNC(ipv6_route, struct bpf_iter_meta *meta, struct fib6_info *rt) 6644 6645 BTF_ID_LIST(btf_fib6_info_id) 6646 BTF_ID(struct, fib6_info) 6647 6648 static const struct bpf_iter_seq_info ipv6_route_seq_info = { 6649 .seq_ops = &ipv6_route_seq_ops, 6650 .init_seq_private = bpf_iter_init_seq_net, 6651 .fini_seq_private = bpf_iter_fini_seq_net, 6652 .seq_priv_size = sizeof(struct ipv6_route_iter), 6653 }; 6654 6655 static struct bpf_iter_reg ipv6_route_reg_info = { 6656 .target = "ipv6_route", 6657 .ctx_arg_info_size = 1, 6658 .ctx_arg_info = { 6659 { offsetof(struct bpf_iter__ipv6_route, rt), 6660 PTR_TO_BTF_ID_OR_NULL }, 6661 }, 6662 .seq_info = &ipv6_route_seq_info, 6663 }; 6664 6665 static int __init bpf_iter_register(void) 6666 { 6667 ipv6_route_reg_info.ctx_arg_info[0].btf_id = *btf_fib6_info_id; 6668 return bpf_iter_reg_target(&ipv6_route_reg_info); 6669 } 6670 6671 static void bpf_iter_unregister(void) 6672 { 6673 bpf_iter_unreg_target(&ipv6_route_reg_info); 6674 } 6675 #endif 6676 #endif 6677 6678 int __init ip6_route_init(void) 6679 { 6680 int ret; 6681 int cpu; 6682 6683 ret = -ENOMEM; 6684 ip6_dst_ops_template.kmem_cachep = 6685 kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0, 6686 SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL); 6687 if (!ip6_dst_ops_template.kmem_cachep) 6688 goto out; 6689 6690 ret = dst_entries_init(&ip6_dst_blackhole_ops); 6691 if (ret) 6692 goto out_kmem_cache; 6693 6694 ret = register_pernet_subsys(&ipv6_inetpeer_ops); 6695 if (ret) 6696 goto out_dst_entries; 6697 6698 ret = register_pernet_subsys(&ip6_route_net_ops); 6699 if (ret) 6700 goto out_register_inetpeer; 6701 6702 ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep; 6703 6704 ret = fib6_init(); 6705 if (ret) 6706 goto out_register_subsys; 6707 6708 ret = xfrm6_init(); 6709 if (ret) 6710 goto out_fib6_init; 6711 6712 ret = fib6_rules_init(); 6713 if (ret) 6714 goto xfrm6_init; 6715 6716 ret = register_pernet_subsys(&ip6_route_net_late_ops); 6717 if (ret) 6718 goto fib6_rules_init; 6719 6720 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_NEWROUTE, 6721 inet6_rtm_newroute, NULL, 0); 6722 if (ret < 0) 6723 goto out_register_late_subsys; 6724 6725 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_DELROUTE, 6726 inet6_rtm_delroute, NULL, 0); 6727 if (ret < 0) 6728 goto out_register_late_subsys; 6729 6730 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, 6731 inet6_rtm_getroute, NULL, 6732 RTNL_FLAG_DOIT_UNLOCKED); 6733 if (ret < 0) 6734 goto out_register_late_subsys; 6735 6736 ret = register_netdevice_notifier(&ip6_route_dev_notifier); 6737 if (ret) 6738 goto out_register_late_subsys; 6739 6740 #if IS_BUILTIN(CONFIG_IPV6) 6741 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) 6742 ret = bpf_iter_register(); 6743 if (ret) 6744 goto out_register_late_subsys; 6745 #endif 6746 #endif 6747 6748 for_each_possible_cpu(cpu) { 6749 struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu); 6750 6751 INIT_LIST_HEAD(&ul->head); 6752 INIT_LIST_HEAD(&ul->quarantine); 6753 spin_lock_init(&ul->lock); 6754 } 6755 6756 out: 6757 return ret; 6758 6759 out_register_late_subsys: 6760 rtnl_unregister_all(PF_INET6); 6761 unregister_pernet_subsys(&ip6_route_net_late_ops); 6762 fib6_rules_init: 6763 fib6_rules_cleanup(); 6764 xfrm6_init: 6765 xfrm6_fini(); 6766 out_fib6_init: 6767 fib6_gc_cleanup(); 6768 out_register_subsys: 6769 unregister_pernet_subsys(&ip6_route_net_ops); 6770 out_register_inetpeer: 6771 unregister_pernet_subsys(&ipv6_inetpeer_ops); 6772 out_dst_entries: 6773 dst_entries_destroy(&ip6_dst_blackhole_ops); 6774 out_kmem_cache: 6775 kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep); 6776 goto out; 6777 } 6778 6779 void ip6_route_cleanup(void) 6780 { 6781 #if IS_BUILTIN(CONFIG_IPV6) 6782 #if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) 6783 bpf_iter_unregister(); 6784 #endif 6785 #endif 6786 unregister_netdevice_notifier(&ip6_route_dev_notifier); 6787 unregister_pernet_subsys(&ip6_route_net_late_ops); 6788 fib6_rules_cleanup(); 6789 xfrm6_fini(); 6790 fib6_gc_cleanup(); 6791 unregister_pernet_subsys(&ipv6_inetpeer_ops); 6792 unregister_pernet_subsys(&ip6_route_net_ops); 6793 dst_entries_destroy(&ip6_dst_blackhole_ops); 6794 kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep); 6795 } 6796