1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 */ 8 9 #ifndef _IP6_FIB_H 10 #define _IP6_FIB_H 11 12 #include <linux/ipv6_route.h> 13 #include <linux/rtnetlink.h> 14 #include <linux/spinlock.h> 15 #include <linux/notifier.h> 16 #include <net/dst.h> 17 #include <net/flow.h> 18 #include <net/ip_fib.h> 19 #include <net/netlink.h> 20 #include <net/inetpeer.h> 21 #include <net/fib_notifier.h> 22 #include <linux/indirect_call_wrapper.h> 23 #include <uapi/linux/bpf.h> 24 25 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 26 #define FIB6_TABLE_HASHSZ 256 27 #else 28 #define FIB6_TABLE_HASHSZ 1 29 #endif 30 31 #define RT6_DEBUG 2 32 33 #if RT6_DEBUG >= 3 34 #define RT6_TRACE(x...) pr_debug(x) 35 #else 36 #define RT6_TRACE(x...) do { ; } while (0) 37 #endif 38 39 struct rt6_info; 40 struct fib6_info; 41 42 struct fib6_config { 43 u32 fc_table; 44 u32 fc_metric; 45 int fc_dst_len; 46 int fc_src_len; 47 int fc_ifindex; 48 u32 fc_flags; 49 u32 fc_protocol; 50 u16 fc_type; /* only 8 bits are used */ 51 u16 fc_delete_all_nh : 1, 52 fc_ignore_dev_down:1, 53 __unused : 14; 54 u32 fc_nh_id; 55 56 struct in6_addr fc_dst; 57 struct in6_addr fc_src; 58 struct in6_addr fc_prefsrc; 59 struct in6_addr fc_gateway; 60 61 unsigned long fc_expires; 62 struct nlattr *fc_mx; 63 int fc_mx_len; 64 int fc_mp_len; 65 struct nlattr *fc_mp; 66 67 struct nl_info fc_nlinfo; 68 struct nlattr *fc_encap; 69 u16 fc_encap_type; 70 bool fc_is_fdb; 71 }; 72 73 struct fib6_node { 74 struct fib6_node __rcu *parent; 75 struct fib6_node __rcu *left; 76 struct fib6_node __rcu *right; 77 #ifdef CONFIG_IPV6_SUBTREES 78 struct fib6_node __rcu *subtree; 79 #endif 80 struct fib6_info __rcu *leaf; 81 82 __u16 fn_bit; /* bit key */ 83 __u16 fn_flags; 84 int fn_sernum; 85 struct fib6_info __rcu *rr_ptr; 86 struct rcu_head rcu; 87 }; 88 89 struct fib6_gc_args { 90 int timeout; 91 int more; 92 }; 93 94 #ifndef CONFIG_IPV6_SUBTREES 95 #define FIB6_SUBTREE(fn) NULL 96 97 static inline bool fib6_routes_require_src(const struct net *net) 98 { 99 return false; 100 } 101 102 static inline void fib6_routes_require_src_inc(struct net *net) {} 103 static inline void fib6_routes_require_src_dec(struct net *net) {} 104 105 #else 106 107 static inline bool fib6_routes_require_src(const struct net *net) 108 { 109 return net->ipv6.fib6_routes_require_src > 0; 110 } 111 112 static inline void fib6_routes_require_src_inc(struct net *net) 113 { 114 net->ipv6.fib6_routes_require_src++; 115 } 116 117 static inline void fib6_routes_require_src_dec(struct net *net) 118 { 119 net->ipv6.fib6_routes_require_src--; 120 } 121 122 #define FIB6_SUBTREE(fn) (rcu_dereference_protected((fn)->subtree, 1)) 123 #endif 124 125 /* 126 * routing information 127 * 128 */ 129 130 struct rt6key { 131 struct in6_addr addr; 132 int plen; 133 }; 134 135 struct fib6_table; 136 137 struct rt6_exception_bucket { 138 struct hlist_head chain; 139 int depth; 140 }; 141 142 struct rt6_exception { 143 struct hlist_node hlist; 144 struct rt6_info *rt6i; 145 unsigned long stamp; 146 struct rcu_head rcu; 147 }; 148 149 #define FIB6_EXCEPTION_BUCKET_SIZE_SHIFT 10 150 #define FIB6_EXCEPTION_BUCKET_SIZE (1 << FIB6_EXCEPTION_BUCKET_SIZE_SHIFT) 151 #define FIB6_MAX_DEPTH 5 152 153 struct fib6_nh { 154 struct fib_nh_common nh_common; 155 156 #ifdef CONFIG_IPV6_ROUTER_PREF 157 unsigned long last_probe; 158 #endif 159 160 struct rt6_info * __percpu *rt6i_pcpu; 161 struct rt6_exception_bucket __rcu *rt6i_exception_bucket; 162 }; 163 164 struct fib6_info { 165 struct fib6_table *fib6_table; 166 struct fib6_info __rcu *fib6_next; 167 struct fib6_node __rcu *fib6_node; 168 169 /* Multipath routes: 170 * siblings is a list of fib6_info that have the same metric/weight, 171 * destination, but not the same gateway. nsiblings is just a cache 172 * to speed up lookup. 173 */ 174 union { 175 struct list_head fib6_siblings; 176 struct list_head nh_list; 177 }; 178 unsigned int fib6_nsiblings; 179 180 refcount_t fib6_ref; 181 unsigned long expires; 182 struct dst_metrics *fib6_metrics; 183 #define fib6_pmtu fib6_metrics->metrics[RTAX_MTU-1] 184 185 struct rt6key fib6_dst; 186 u32 fib6_flags; 187 struct rt6key fib6_src; 188 struct rt6key fib6_prefsrc; 189 190 u32 fib6_metric; 191 u8 fib6_protocol; 192 u8 fib6_type; 193 u8 should_flush:1, 194 dst_nocount:1, 195 dst_nopolicy:1, 196 fib6_destroying:1, 197 offload:1, 198 trap:1, 199 offload_failed:1, 200 unused:1; 201 202 struct rcu_head rcu; 203 struct nexthop *nh; 204 struct fib6_nh fib6_nh[]; 205 }; 206 207 struct rt6_info { 208 struct dst_entry dst; 209 struct fib6_info __rcu *from; 210 int sernum; 211 212 struct rt6key rt6i_dst; 213 struct rt6key rt6i_src; 214 struct in6_addr rt6i_gateway; 215 struct inet6_dev *rt6i_idev; 216 u32 rt6i_flags; 217 218 struct list_head rt6i_uncached; 219 struct uncached_list *rt6i_uncached_list; 220 221 /* more non-fragment space at head required */ 222 unsigned short rt6i_nfheader_len; 223 }; 224 225 struct fib6_result { 226 struct fib6_nh *nh; 227 struct fib6_info *f6i; 228 u32 fib6_flags; 229 u8 fib6_type; 230 struct rt6_info *rt6; 231 }; 232 233 #define for_each_fib6_node_rt_rcu(fn) \ 234 for (rt = rcu_dereference((fn)->leaf); rt; \ 235 rt = rcu_dereference(rt->fib6_next)) 236 237 #define for_each_fib6_walker_rt(w) \ 238 for (rt = (w)->leaf; rt; \ 239 rt = rcu_dereference_protected(rt->fib6_next, 1)) 240 241 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst) 242 { 243 return ((struct rt6_info *)dst)->rt6i_idev; 244 } 245 246 static inline bool fib6_requires_src(const struct fib6_info *rt) 247 { 248 return rt->fib6_src.plen > 0; 249 } 250 251 static inline void fib6_clean_expires(struct fib6_info *f6i) 252 { 253 f6i->fib6_flags &= ~RTF_EXPIRES; 254 f6i->expires = 0; 255 } 256 257 static inline void fib6_set_expires(struct fib6_info *f6i, 258 unsigned long expires) 259 { 260 f6i->expires = expires; 261 f6i->fib6_flags |= RTF_EXPIRES; 262 } 263 264 static inline bool fib6_check_expired(const struct fib6_info *f6i) 265 { 266 if (f6i->fib6_flags & RTF_EXPIRES) 267 return time_after(jiffies, f6i->expires); 268 return false; 269 } 270 271 /* Function to safely get fn->fn_sernum for passed in rt 272 * and store result in passed in cookie. 273 * Return true if we can get cookie safely 274 * Return false if not 275 */ 276 static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i, 277 u32 *cookie) 278 { 279 struct fib6_node *fn; 280 bool status = false; 281 282 fn = rcu_dereference(f6i->fib6_node); 283 284 if (fn) { 285 *cookie = fn->fn_sernum; 286 /* pairs with smp_wmb() in __fib6_update_sernum_upto_root() */ 287 smp_rmb(); 288 status = true; 289 } 290 291 return status; 292 } 293 294 static inline u32 rt6_get_cookie(const struct rt6_info *rt) 295 { 296 struct fib6_info *from; 297 u32 cookie = 0; 298 299 if (rt->sernum) 300 return rt->sernum; 301 302 rcu_read_lock(); 303 304 from = rcu_dereference(rt->from); 305 if (from) 306 fib6_get_cookie_safe(from, &cookie); 307 308 rcu_read_unlock(); 309 310 return cookie; 311 } 312 313 static inline void ip6_rt_put(struct rt6_info *rt) 314 { 315 /* dst_release() accepts a NULL parameter. 316 * We rely on dst being first structure in struct rt6_info 317 */ 318 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0); 319 dst_release(&rt->dst); 320 } 321 322 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh); 323 void fib6_info_destroy_rcu(struct rcu_head *head); 324 325 static inline void fib6_info_hold(struct fib6_info *f6i) 326 { 327 refcount_inc(&f6i->fib6_ref); 328 } 329 330 static inline bool fib6_info_hold_safe(struct fib6_info *f6i) 331 { 332 return refcount_inc_not_zero(&f6i->fib6_ref); 333 } 334 335 static inline void fib6_info_release(struct fib6_info *f6i) 336 { 337 if (f6i && refcount_dec_and_test(&f6i->fib6_ref)) 338 call_rcu(&f6i->rcu, fib6_info_destroy_rcu); 339 } 340 341 enum fib6_walk_state { 342 #ifdef CONFIG_IPV6_SUBTREES 343 FWS_S, 344 #endif 345 FWS_L, 346 FWS_R, 347 FWS_C, 348 FWS_U 349 }; 350 351 struct fib6_walker { 352 struct list_head lh; 353 struct fib6_node *root, *node; 354 struct fib6_info *leaf; 355 enum fib6_walk_state state; 356 unsigned int skip; 357 unsigned int count; 358 unsigned int skip_in_node; 359 int (*func)(struct fib6_walker *); 360 void *args; 361 }; 362 363 struct rt6_statistics { 364 __u32 fib_nodes; /* all fib6 nodes */ 365 __u32 fib_route_nodes; /* intermediate nodes */ 366 __u32 fib_rt_entries; /* rt entries in fib table */ 367 __u32 fib_rt_cache; /* cached rt entries in exception table */ 368 __u32 fib_discarded_routes; /* total number of routes delete */ 369 370 /* The following stats are not protected by any lock */ 371 atomic_t fib_rt_alloc; /* total number of routes alloced */ 372 atomic_t fib_rt_uncache; /* rt entries in uncached list */ 373 }; 374 375 #define RTN_TL_ROOT 0x0001 376 #define RTN_ROOT 0x0002 /* tree root node */ 377 #define RTN_RTINFO 0x0004 /* node with valid routing info */ 378 379 /* 380 * priority levels (or metrics) 381 * 382 */ 383 384 385 struct fib6_table { 386 struct hlist_node tb6_hlist; 387 u32 tb6_id; 388 spinlock_t tb6_lock; 389 struct fib6_node tb6_root; 390 struct inet_peer_base tb6_peers; 391 unsigned int flags; 392 unsigned int fib_seq; 393 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0) 394 }; 395 396 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC 397 #define RT6_TABLE_MAIN RT_TABLE_MAIN 398 #define RT6_TABLE_DFLT RT6_TABLE_MAIN 399 #define RT6_TABLE_INFO RT6_TABLE_MAIN 400 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN 401 402 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 403 #define FIB6_TABLE_MIN 1 404 #define FIB6_TABLE_MAX RT_TABLE_MAX 405 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL 406 #else 407 #define FIB6_TABLE_MIN RT_TABLE_MAIN 408 #define FIB6_TABLE_MAX FIB6_TABLE_MIN 409 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN 410 #endif 411 412 typedef struct rt6_info *(*pol_lookup_t)(struct net *, 413 struct fib6_table *, 414 struct flowi6 *, 415 const struct sk_buff *, int); 416 417 struct fib6_entry_notifier_info { 418 struct fib_notifier_info info; /* must be first */ 419 struct fib6_info *rt; 420 unsigned int nsiblings; 421 }; 422 423 /* 424 * exported functions 425 */ 426 427 struct fib6_table *fib6_get_table(struct net *net, u32 id); 428 struct fib6_table *fib6_new_table(struct net *net, u32 id); 429 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 430 const struct sk_buff *skb, 431 int flags, pol_lookup_t lookup); 432 433 /* called with rcu lock held; can return error pointer 434 * caller needs to select path 435 */ 436 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, 437 struct fib6_result *res, int flags); 438 439 /* called with rcu lock held; caller needs to select path */ 440 int fib6_table_lookup(struct net *net, struct fib6_table *table, 441 int oif, struct flowi6 *fl6, struct fib6_result *res, 442 int strict); 443 444 void fib6_select_path(const struct net *net, struct fib6_result *res, 445 struct flowi6 *fl6, int oif, bool have_oif_match, 446 const struct sk_buff *skb, int strict); 447 struct fib6_node *fib6_node_lookup(struct fib6_node *root, 448 const struct in6_addr *daddr, 449 const struct in6_addr *saddr); 450 451 struct fib6_node *fib6_locate(struct fib6_node *root, 452 const struct in6_addr *daddr, int dst_len, 453 const struct in6_addr *saddr, int src_len, 454 bool exact_match); 455 456 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg), 457 void *arg); 458 void fib6_clean_all_skip_notify(struct net *net, 459 int (*func)(struct fib6_info *, void *arg), 460 void *arg); 461 462 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 463 struct nl_info *info, struct netlink_ext_ack *extack); 464 int fib6_del(struct fib6_info *rt, struct nl_info *info); 465 466 static inline 467 void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr) 468 { 469 const struct fib6_info *from; 470 471 rcu_read_lock(); 472 473 from = rcu_dereference(rt->from); 474 if (from) { 475 *addr = from->fib6_prefsrc.addr; 476 } else { 477 struct in6_addr in6_zero = {}; 478 479 *addr = in6_zero; 480 } 481 482 rcu_read_unlock(); 483 } 484 485 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh, 486 struct fib6_config *cfg, gfp_t gfp_flags, 487 struct netlink_ext_ack *extack); 488 void fib6_nh_release(struct fib6_nh *fib6_nh); 489 void fib6_nh_release_dsts(struct fib6_nh *fib6_nh); 490 491 int call_fib6_entry_notifiers(struct net *net, 492 enum fib_event_type event_type, 493 struct fib6_info *rt, 494 struct netlink_ext_ack *extack); 495 int call_fib6_multipath_entry_notifiers(struct net *net, 496 enum fib_event_type event_type, 497 struct fib6_info *rt, 498 unsigned int nsiblings, 499 struct netlink_ext_ack *extack); 500 int call_fib6_entry_notifiers_replace(struct net *net, struct fib6_info *rt); 501 void fib6_rt_update(struct net *net, struct fib6_info *rt, 502 struct nl_info *info); 503 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info, 504 unsigned int flags); 505 506 void fib6_run_gc(unsigned long expires, struct net *net, bool force); 507 508 void fib6_gc_cleanup(void); 509 510 int fib6_init(void); 511 512 struct ipv6_route_iter { 513 struct seq_net_private p; 514 struct fib6_walker w; 515 loff_t skip; 516 struct fib6_table *tbl; 517 int sernum; 518 }; 519 520 extern const struct seq_operations ipv6_route_seq_ops; 521 522 int call_fib6_notifier(struct notifier_block *nb, 523 enum fib_event_type event_type, 524 struct fib_notifier_info *info); 525 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type, 526 struct fib_notifier_info *info); 527 528 int __net_init fib6_notifier_init(struct net *net); 529 void __net_exit fib6_notifier_exit(struct net *net); 530 531 unsigned int fib6_tables_seq_read(struct net *net); 532 int fib6_tables_dump(struct net *net, struct notifier_block *nb, 533 struct netlink_ext_ack *extack); 534 535 void fib6_update_sernum(struct net *net, struct fib6_info *rt); 536 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt); 537 void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i); 538 539 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val); 540 static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric) 541 { 542 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric)); 543 } 544 void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i, 545 bool offload, bool trap, bool offload_failed); 546 547 #if IS_BUILTIN(CONFIG_IPV6) && defined(CONFIG_BPF_SYSCALL) 548 struct bpf_iter__ipv6_route { 549 __bpf_md_ptr(struct bpf_iter_meta *, meta); 550 __bpf_md_ptr(struct fib6_info *, rt); 551 }; 552 #endif 553 554 INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_output(struct net *net, 555 struct fib6_table *table, 556 struct flowi6 *fl6, 557 const struct sk_buff *skb, 558 int flags)); 559 INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_input(struct net *net, 560 struct fib6_table *table, 561 struct flowi6 *fl6, 562 const struct sk_buff *skb, 563 int flags)); 564 INDIRECT_CALLABLE_DECLARE(struct rt6_info *__ip6_route_redirect(struct net *net, 565 struct fib6_table *table, 566 struct flowi6 *fl6, 567 const struct sk_buff *skb, 568 int flags)); 569 INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_lookup(struct net *net, 570 struct fib6_table *table, 571 struct flowi6 *fl6, 572 const struct sk_buff *skb, 573 int flags)); 574 static inline struct rt6_info *pol_lookup_func(pol_lookup_t lookup, 575 struct net *net, 576 struct fib6_table *table, 577 struct flowi6 *fl6, 578 const struct sk_buff *skb, 579 int flags) 580 { 581 return INDIRECT_CALL_4(lookup, 582 ip6_pol_route_output, 583 ip6_pol_route_input, 584 ip6_pol_route_lookup, 585 __ip6_route_redirect, 586 net, table, fl6, skb, flags); 587 } 588 589 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 590 static inline bool fib6_has_custom_rules(const struct net *net) 591 { 592 return net->ipv6.fib6_has_custom_rules; 593 } 594 595 int fib6_rules_init(void); 596 void fib6_rules_cleanup(void); 597 bool fib6_rule_default(const struct fib_rule *rule); 598 int fib6_rules_dump(struct net *net, struct notifier_block *nb, 599 struct netlink_ext_ack *extack); 600 unsigned int fib6_rules_seq_read(struct net *net); 601 602 static inline bool fib6_rules_early_flow_dissect(struct net *net, 603 struct sk_buff *skb, 604 struct flowi6 *fl6, 605 struct flow_keys *flkeys) 606 { 607 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 608 609 if (!net->ipv6.fib6_rules_require_fldissect) 610 return false; 611 612 skb_flow_dissect_flow_keys(skb, flkeys, flag); 613 fl6->fl6_sport = flkeys->ports.src; 614 fl6->fl6_dport = flkeys->ports.dst; 615 fl6->flowi6_proto = flkeys->basic.ip_proto; 616 617 return true; 618 } 619 #else 620 static inline bool fib6_has_custom_rules(const struct net *net) 621 { 622 return false; 623 } 624 static inline int fib6_rules_init(void) 625 { 626 return 0; 627 } 628 static inline void fib6_rules_cleanup(void) 629 { 630 return ; 631 } 632 static inline bool fib6_rule_default(const struct fib_rule *rule) 633 { 634 return true; 635 } 636 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb, 637 struct netlink_ext_ack *extack) 638 { 639 return 0; 640 } 641 static inline unsigned int fib6_rules_seq_read(struct net *net) 642 { 643 return 0; 644 } 645 static inline bool fib6_rules_early_flow_dissect(struct net *net, 646 struct sk_buff *skb, 647 struct flowi6 *fl6, 648 struct flow_keys *flkeys) 649 { 650 return false; 651 } 652 #endif 653 #endif 654