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 39struct rt6_info; 40struct fib6_info; 41 42struct 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 73struct 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 89struct fib6_gc_args { 90 int timeout; 91 int more; 92}; 93 94#ifndef CONFIG_IPV6_SUBTREES 95#define FIB6_SUBTREE(fn) NULL 96 97static inline bool fib6_routes_require_src(const struct net *net) 98{ 99 return false; 100} 101 102static inline void fib6_routes_require_src_inc(struct net *net) {} 103static inline void fib6_routes_require_src_dec(struct net *net) {} 104 105#else 106 107static inline bool fib6_routes_require_src(const struct net *net) 108{ 109 return net->ipv6.fib6_routes_require_src > 0; 110} 111 112static inline void fib6_routes_require_src_inc(struct net *net) 113{ 114 net->ipv6.fib6_routes_require_src++; 115} 116 117static 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 130struct rt6key { 131 struct in6_addr addr; 132 int plen; 133}; 134 135struct fib6_table; 136 137struct rt6_exception_bucket { 138 struct hlist_head chain; 139 int depth; 140}; 141 142struct 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 153struct 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 164struct 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; 193 194 u8 offload; 195 u8 trap; 196 u8 offload_failed; 197 198 u8 should_flush:1, 199 dst_nocount:1, 200 dst_nopolicy:1, 201 fib6_destroying:1, 202 unused:4; 203 204 struct rcu_head rcu; 205 struct nexthop *nh; 206 struct fib6_nh fib6_nh[]; 207}; 208 209struct rt6_info { 210 struct dst_entry dst; 211 struct fib6_info __rcu *from; 212 int sernum; 213 214 struct rt6key rt6i_dst; 215 struct rt6key rt6i_src; 216 struct in6_addr rt6i_gateway; 217 struct inet6_dev *rt6i_idev; 218 u32 rt6i_flags; 219 220 /* more non-fragment space at head required */ 221 unsigned short rt6i_nfheader_len; 222}; 223 224struct 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 240static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst) 241{ 242 return ((struct rt6_info *)dst)->rt6i_idev; 243} 244 245static inline bool fib6_requires_src(const struct fib6_info *rt) 246{ 247 return rt->fib6_src.plen > 0; 248} 249 250static inline void fib6_clean_expires(struct fib6_info *f6i) 251{ 252 f6i->fib6_flags &= ~RTF_EXPIRES; 253 f6i->expires = 0; 254} 255 256static 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 263static 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 */ 275static 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 = READ_ONCE(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 293static 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 312static 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 321struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh); 322void fib6_info_destroy_rcu(struct rcu_head *head); 323 324static inline void fib6_info_hold(struct fib6_info *f6i) 325{ 326 refcount_inc(&f6i->fib6_ref); 327} 328 329static inline bool fib6_info_hold_safe(struct fib6_info *f6i) 330{ 331 return refcount_inc_not_zero(&f6i->fib6_ref); 332} 333 334static 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 340enum 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 350struct 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 362struct 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 stat is not protected by any lock */ 370 atomic_t fib_rt_alloc; /* total number of routes alloced */ 371}; 372 373#define RTN_TL_ROOT 0x0001 374#define RTN_ROOT 0x0002 /* tree root node */ 375#define RTN_RTINFO 0x0004 /* node with valid routing info */ 376 377/* 378 * priority levels (or metrics) 379 * 380 */ 381 382 383struct fib6_table { 384 struct hlist_node tb6_hlist; 385 u32 tb6_id; 386 spinlock_t tb6_lock; 387 struct fib6_node tb6_root; 388 struct inet_peer_base tb6_peers; 389 unsigned int flags; 390 unsigned int fib_seq; 391#define RT6_TABLE_HAS_DFLT_ROUTER BIT(0) 392}; 393 394#define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC 395#define RT6_TABLE_MAIN RT_TABLE_MAIN 396#define RT6_TABLE_DFLT RT6_TABLE_MAIN 397#define RT6_TABLE_INFO RT6_TABLE_MAIN 398#define RT6_TABLE_PREFIX RT6_TABLE_MAIN 399 400#ifdef CONFIG_IPV6_MULTIPLE_TABLES 401#define FIB6_TABLE_MIN 1 402#define FIB6_TABLE_MAX RT_TABLE_MAX 403#define RT6_TABLE_LOCAL RT_TABLE_LOCAL 404#else 405#define FIB6_TABLE_MIN RT_TABLE_MAIN 406#define FIB6_TABLE_MAX FIB6_TABLE_MIN 407#define RT6_TABLE_LOCAL RT6_TABLE_MAIN 408#endif 409 410typedef struct rt6_info *(*pol_lookup_t)(struct net *, 411 struct fib6_table *, 412 struct flowi6 *, 413 const struct sk_buff *, int); 414 415struct fib6_entry_notifier_info { 416 struct fib_notifier_info info; /* must be first */ 417 struct fib6_info *rt; 418 unsigned int nsiblings; 419}; 420 421/* 422 * exported functions 423 */ 424 425struct fib6_table *fib6_get_table(struct net *net, u32 id); 426struct fib6_table *fib6_new_table(struct net *net, u32 id); 427struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 428 const struct sk_buff *skb, 429 int flags, pol_lookup_t lookup); 430 431/* called with rcu lock held; can return error pointer 432 * caller needs to select path 433 */ 434int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, 435 struct fib6_result *res, int flags); 436 437/* called with rcu lock held; caller needs to select path */ 438int fib6_table_lookup(struct net *net, struct fib6_table *table, 439 int oif, struct flowi6 *fl6, struct fib6_result *res, 440 int strict); 441 442void fib6_select_path(const struct net *net, struct fib6_result *res, 443 struct flowi6 *fl6, int oif, bool have_oif_match, 444 const struct sk_buff *skb, int strict); 445struct fib6_node *fib6_node_lookup(struct fib6_node *root, 446 const struct in6_addr *daddr, 447 const struct in6_addr *saddr); 448 449struct fib6_node *fib6_locate(struct fib6_node *root, 450 const struct in6_addr *daddr, int dst_len, 451 const struct in6_addr *saddr, int src_len, 452 bool exact_match); 453 454void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg), 455 void *arg); 456void fib6_clean_all_skip_notify(struct net *net, 457 int (*func)(struct fib6_info *, void *arg), 458 void *arg); 459 460int fib6_add(struct fib6_node *root, struct fib6_info *rt, 461 struct nl_info *info, struct netlink_ext_ack *extack); 462int fib6_del(struct fib6_info *rt, struct nl_info *info); 463 464static inline 465void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr) 466{ 467 const struct fib6_info *from; 468 469 rcu_read_lock(); 470 471 from = rcu_dereference(rt->from); 472 if (from) 473 *addr = from->fib6_prefsrc.addr; 474 else 475 *addr = in6addr_any; 476 477 rcu_read_unlock(); 478} 479 480int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh, 481 struct fib6_config *cfg, gfp_t gfp_flags, 482 struct netlink_ext_ack *extack); 483void fib6_nh_release(struct fib6_nh *fib6_nh); 484void fib6_nh_release_dsts(struct fib6_nh *fib6_nh); 485 486int call_fib6_entry_notifiers(struct net *net, 487 enum fib_event_type event_type, 488 struct fib6_info *rt, 489 struct netlink_ext_ack *extack); 490int call_fib6_multipath_entry_notifiers(struct net *net, 491 enum fib_event_type event_type, 492 struct fib6_info *rt, 493 unsigned int nsiblings, 494 struct netlink_ext_ack *extack); 495int call_fib6_entry_notifiers_replace(struct net *net, struct fib6_info *rt); 496void fib6_rt_update(struct net *net, struct fib6_info *rt, 497 struct nl_info *info); 498void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info, 499 unsigned int flags); 500 501void fib6_run_gc(unsigned long expires, struct net *net, bool force); 502 503void fib6_gc_cleanup(void); 504 505int fib6_init(void); 506 507struct ipv6_route_iter { 508 struct seq_net_private p; 509 struct fib6_walker w; 510 loff_t skip; 511 struct fib6_table *tbl; 512 int sernum; 513}; 514 515extern const struct seq_operations ipv6_route_seq_ops; 516 517int call_fib6_notifier(struct notifier_block *nb, 518 enum fib_event_type event_type, 519 struct fib_notifier_info *info); 520int call_fib6_notifiers(struct net *net, enum fib_event_type event_type, 521 struct fib_notifier_info *info); 522 523int __net_init fib6_notifier_init(struct net *net); 524void __net_exit fib6_notifier_exit(struct net *net); 525 526unsigned int fib6_tables_seq_read(struct net *net); 527int fib6_tables_dump(struct net *net, struct notifier_block *nb, 528 struct netlink_ext_ack *extack); 529 530void fib6_update_sernum(struct net *net, struct fib6_info *rt); 531void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt); 532void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i); 533 534void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val); 535static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric) 536{ 537 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric)); 538} 539void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i, 540 bool offload, bool trap, bool offload_failed); 541 542#if IS_BUILTIN(CONFIG_IPV6) && defined(CONFIG_BPF_SYSCALL) 543struct bpf_iter__ipv6_route { 544 __bpf_md_ptr(struct bpf_iter_meta *, meta); 545 __bpf_md_ptr(struct fib6_info *, rt); 546}; 547#endif 548 549INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_output(struct net *net, 550 struct fib6_table *table, 551 struct flowi6 *fl6, 552 const struct sk_buff *skb, 553 int flags)); 554INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_input(struct net *net, 555 struct fib6_table *table, 556 struct flowi6 *fl6, 557 const struct sk_buff *skb, 558 int flags)); 559INDIRECT_CALLABLE_DECLARE(struct rt6_info *__ip6_route_redirect(struct net *net, 560 struct fib6_table *table, 561 struct flowi6 *fl6, 562 const struct sk_buff *skb, 563 int flags)); 564INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_lookup(struct net *net, 565 struct fib6_table *table, 566 struct flowi6 *fl6, 567 const struct sk_buff *skb, 568 int flags)); 569static inline struct rt6_info *pol_lookup_func(pol_lookup_t lookup, 570 struct net *net, 571 struct fib6_table *table, 572 struct flowi6 *fl6, 573 const struct sk_buff *skb, 574 int flags) 575{ 576 return INDIRECT_CALL_4(lookup, 577 ip6_pol_route_output, 578 ip6_pol_route_input, 579 ip6_pol_route_lookup, 580 __ip6_route_redirect, 581 net, table, fl6, skb, flags); 582} 583 584#ifdef CONFIG_IPV6_MULTIPLE_TABLES 585static inline bool fib6_has_custom_rules(const struct net *net) 586{ 587 return net->ipv6.fib6_has_custom_rules; 588} 589 590int fib6_rules_init(void); 591void fib6_rules_cleanup(void); 592bool fib6_rule_default(const struct fib_rule *rule); 593int fib6_rules_dump(struct net *net, struct notifier_block *nb, 594 struct netlink_ext_ack *extack); 595unsigned int fib6_rules_seq_read(struct net *net); 596 597static inline bool fib6_rules_early_flow_dissect(struct net *net, 598 struct sk_buff *skb, 599 struct flowi6 *fl6, 600 struct flow_keys *flkeys) 601{ 602 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 603 604 if (!net->ipv6.fib6_rules_require_fldissect) 605 return false; 606 607 memset(flkeys, 0, sizeof(*flkeys)); 608 __skb_flow_dissect(net, skb, &flow_keys_dissector, 609 flkeys, NULL, 0, 0, 0, flag); 610 611 fl6->fl6_sport = flkeys->ports.src; 612 fl6->fl6_dport = flkeys->ports.dst; 613 fl6->flowi6_proto = flkeys->basic.ip_proto; 614 615 return true; 616} 617#else 618static inline bool fib6_has_custom_rules(const struct net *net) 619{ 620 return false; 621} 622static inline int fib6_rules_init(void) 623{ 624 return 0; 625} 626static inline void fib6_rules_cleanup(void) 627{ 628 return ; 629} 630static inline bool fib6_rule_default(const struct fib_rule *rule) 631{ 632 return true; 633} 634static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb, 635 struct netlink_ext_ack *extack) 636{ 637 return 0; 638} 639static inline unsigned int fib6_rules_seq_read(struct net *net) 640{ 641 return 0; 642} 643static inline bool fib6_rules_early_flow_dissect(struct net *net, 644 struct sk_buff *skb, 645 struct flowi6 *fl6, 646 struct flow_keys *flkeys) 647{ 648 return false; 649} 650#endif 651#endif 652