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