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 struct rt6_info; 34 struct fib6_info; 35 36 struct fib6_config { 37 u32 fc_table; 38 u32 fc_metric; 39 int fc_dst_len; 40 int fc_src_len; 41 int fc_ifindex; 42 u32 fc_flags; 43 u32 fc_protocol; 44 u16 fc_type; /* only 8 bits are used */ 45 u16 fc_delete_all_nh : 1, 46 fc_ignore_dev_down:1, 47 __unused : 14; 48 u32 fc_nh_id; 49 50 struct in6_addr fc_dst; 51 struct in6_addr fc_src; 52 struct in6_addr fc_prefsrc; 53 struct in6_addr fc_gateway; 54 55 unsigned long fc_expires; 56 struct nlattr *fc_mx; 57 int fc_mx_len; 58 int fc_mp_len; 59 struct nlattr *fc_mp; 60 61 struct nl_info fc_nlinfo; 62 struct nlattr *fc_encap; 63 u16 fc_encap_type; 64 bool fc_is_fdb; 65 }; 66 67 struct fib6_node { 68 struct fib6_node __rcu *parent; 69 struct fib6_node __rcu *left; 70 struct fib6_node __rcu *right; 71 #ifdef CONFIG_IPV6_SUBTREES 72 struct fib6_node __rcu *subtree; 73 #endif 74 struct fib6_info __rcu *leaf; 75 76 __u16 fn_bit; /* bit key */ 77 __u16 fn_flags; 78 int fn_sernum; 79 struct fib6_info __rcu *rr_ptr; 80 struct rcu_head rcu; 81 }; 82 83 struct fib6_gc_args { 84 int timeout; 85 int more; 86 }; 87 88 #ifndef CONFIG_IPV6_SUBTREES 89 #define FIB6_SUBTREE(fn) NULL 90 91 static inline bool fib6_routes_require_src(const struct net *net) 92 { 93 return false; 94 } 95 96 static inline void fib6_routes_require_src_inc(struct net *net) {} 97 static inline void fib6_routes_require_src_dec(struct net *net) {} 98 99 #else 100 101 static inline bool fib6_routes_require_src(const struct net *net) 102 { 103 return net->ipv6.fib6_routes_require_src > 0; 104 } 105 106 static inline void fib6_routes_require_src_inc(struct net *net) 107 { 108 net->ipv6.fib6_routes_require_src++; 109 } 110 111 static inline void fib6_routes_require_src_dec(struct net *net) 112 { 113 net->ipv6.fib6_routes_require_src--; 114 } 115 116 #define FIB6_SUBTREE(fn) (rcu_dereference_protected((fn)->subtree, 1)) 117 #endif 118 119 /* 120 * routing information 121 * 122 */ 123 124 struct rt6key { 125 struct in6_addr addr; 126 int plen; 127 }; 128 129 struct fib6_table; 130 131 struct rt6_exception_bucket { 132 struct hlist_head chain; 133 int depth; 134 }; 135 136 struct rt6_exception { 137 struct hlist_node hlist; 138 struct rt6_info *rt6i; 139 unsigned long stamp; 140 struct rcu_head rcu; 141 }; 142 143 #define FIB6_EXCEPTION_BUCKET_SIZE_SHIFT 10 144 #define FIB6_EXCEPTION_BUCKET_SIZE (1 << FIB6_EXCEPTION_BUCKET_SIZE_SHIFT) 145 #define FIB6_MAX_DEPTH 5 146 147 struct fib6_nh { 148 struct fib_nh_common nh_common; 149 150 #ifdef CONFIG_IPV6_ROUTER_PREF 151 unsigned long last_probe; 152 #endif 153 154 struct rt6_info * __percpu *rt6i_pcpu; 155 struct rt6_exception_bucket __rcu *rt6i_exception_bucket; 156 }; 157 158 struct fib6_info { 159 struct fib6_table *fib6_table; 160 struct fib6_info __rcu *fib6_next; 161 struct fib6_node __rcu *fib6_node; 162 163 /* Multipath routes: 164 * siblings is a list of fib6_info that have the same metric/weight, 165 * destination, but not the same gateway. nsiblings is just a cache 166 * to speed up lookup. 167 */ 168 union { 169 struct list_head fib6_siblings; 170 struct list_head nh_list; 171 }; 172 unsigned int fib6_nsiblings; 173 174 refcount_t fib6_ref; 175 unsigned long expires; 176 struct dst_metrics *fib6_metrics; 177 #define fib6_pmtu fib6_metrics->metrics[RTAX_MTU-1] 178 179 struct rt6key fib6_dst; 180 u32 fib6_flags; 181 struct rt6key fib6_src; 182 struct rt6key fib6_prefsrc; 183 184 u32 fib6_metric; 185 u8 fib6_protocol; 186 u8 fib6_type; 187 188 u8 offload; 189 u8 trap; 190 u8 offload_failed; 191 192 u8 should_flush:1, 193 dst_nocount:1, 194 dst_nopolicy:1, 195 fib6_destroying:1, 196 unused:4; 197 198 struct rcu_head rcu; 199 struct nexthop *nh; 200 struct fib6_nh fib6_nh[]; 201 }; 202 203 struct rt6_info { 204 struct dst_entry dst; 205 struct fib6_info __rcu *from; 206 int sernum; 207 208 struct rt6key rt6i_dst; 209 struct rt6key rt6i_src; 210 struct in6_addr rt6i_gateway; 211 struct inet6_dev *rt6i_idev; 212 u32 rt6i_flags; 213 214 /* more non-fragment space at head required */ 215 unsigned short rt6i_nfheader_len; 216 }; 217 218 struct fib6_result { 219 struct fib6_nh *nh; 220 struct fib6_info *f6i; 221 u32 fib6_flags; 222 u8 fib6_type; 223 struct rt6_info *rt6; 224 }; 225 226 #define for_each_fib6_node_rt_rcu(fn) \ 227 for (rt = rcu_dereference((fn)->leaf); rt; \ 228 rt = rcu_dereference(rt->fib6_next)) 229 230 #define for_each_fib6_walker_rt(w) \ 231 for (rt = (w)->leaf; rt; \ 232 rt = rcu_dereference_protected(rt->fib6_next, 1)) 233 234 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst) 235 { 236 return ((struct rt6_info *)dst)->rt6i_idev; 237 } 238 239 static inline bool fib6_requires_src(const struct fib6_info *rt) 240 { 241 return rt->fib6_src.plen > 0; 242 } 243 244 static inline void fib6_clean_expires(struct fib6_info *f6i) 245 { 246 f6i->fib6_flags &= ~RTF_EXPIRES; 247 f6i->expires = 0; 248 } 249 250 static inline void fib6_set_expires(struct fib6_info *f6i, 251 unsigned long expires) 252 { 253 f6i->expires = expires; 254 f6i->fib6_flags |= RTF_EXPIRES; 255 } 256 257 static inline bool fib6_check_expired(const struct fib6_info *f6i) 258 { 259 if (f6i->fib6_flags & RTF_EXPIRES) 260 return time_after(jiffies, f6i->expires); 261 return false; 262 } 263 264 /* Function to safely get fn->fn_sernum for passed in rt 265 * and store result in passed in cookie. 266 * Return true if we can get cookie safely 267 * Return false if not 268 */ 269 static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i, 270 u32 *cookie) 271 { 272 struct fib6_node *fn; 273 bool status = false; 274 275 fn = rcu_dereference(f6i->fib6_node); 276 277 if (fn) { 278 *cookie = READ_ONCE(fn->fn_sernum); 279 /* pairs with smp_wmb() in __fib6_update_sernum_upto_root() */ 280 smp_rmb(); 281 status = true; 282 } 283 284 return status; 285 } 286 287 static inline u32 rt6_get_cookie(const struct rt6_info *rt) 288 { 289 struct fib6_info *from; 290 u32 cookie = 0; 291 292 if (rt->sernum) 293 return rt->sernum; 294 295 rcu_read_lock(); 296 297 from = rcu_dereference(rt->from); 298 if (from) 299 fib6_get_cookie_safe(from, &cookie); 300 301 rcu_read_unlock(); 302 303 return cookie; 304 } 305 306 static inline void ip6_rt_put(struct rt6_info *rt) 307 { 308 /* dst_release() accepts a NULL parameter. 309 * We rely on dst being first structure in struct rt6_info 310 */ 311 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0); 312 dst_release(&rt->dst); 313 } 314 315 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh); 316 void fib6_info_destroy_rcu(struct rcu_head *head); 317 318 static inline void fib6_info_hold(struct fib6_info *f6i) 319 { 320 refcount_inc(&f6i->fib6_ref); 321 } 322 323 static inline bool fib6_info_hold_safe(struct fib6_info *f6i) 324 { 325 return refcount_inc_not_zero(&f6i->fib6_ref); 326 } 327 328 static inline void fib6_info_release(struct fib6_info *f6i) 329 { 330 if (f6i && refcount_dec_and_test(&f6i->fib6_ref)) 331 call_rcu(&f6i->rcu, fib6_info_destroy_rcu); 332 } 333 334 enum fib6_walk_state { 335 #ifdef CONFIG_IPV6_SUBTREES 336 FWS_S, 337 #endif 338 FWS_L, 339 FWS_R, 340 FWS_C, 341 FWS_U 342 }; 343 344 struct fib6_walker { 345 struct list_head lh; 346 struct fib6_node *root, *node; 347 struct fib6_info *leaf; 348 enum fib6_walk_state state; 349 unsigned int skip; 350 unsigned int count; 351 unsigned int skip_in_node; 352 int (*func)(struct fib6_walker *); 353 void *args; 354 }; 355 356 struct rt6_statistics { 357 __u32 fib_nodes; /* all fib6 nodes */ 358 __u32 fib_route_nodes; /* intermediate nodes */ 359 __u32 fib_rt_entries; /* rt entries in fib table */ 360 __u32 fib_rt_cache; /* cached rt entries in exception table */ 361 __u32 fib_discarded_routes; /* total number of routes delete */ 362 363 /* The following stat is not protected by any lock */ 364 atomic_t fib_rt_alloc; /* total number of routes alloced */ 365 }; 366 367 #define RTN_TL_ROOT 0x0001 368 #define RTN_ROOT 0x0002 /* tree root node */ 369 #define RTN_RTINFO 0x0004 /* node with valid routing info */ 370 371 /* 372 * priority levels (or metrics) 373 * 374 */ 375 376 377 struct fib6_table { 378 struct hlist_node tb6_hlist; 379 u32 tb6_id; 380 spinlock_t tb6_lock; 381 struct fib6_node tb6_root; 382 struct inet_peer_base tb6_peers; 383 unsigned int flags; 384 unsigned int fib_seq; 385 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0) 386 }; 387 388 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC 389 #define RT6_TABLE_MAIN RT_TABLE_MAIN 390 #define RT6_TABLE_DFLT RT6_TABLE_MAIN 391 #define RT6_TABLE_INFO RT6_TABLE_MAIN 392 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN 393 394 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 395 #define FIB6_TABLE_MIN 1 396 #define FIB6_TABLE_MAX RT_TABLE_MAX 397 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL 398 #else 399 #define FIB6_TABLE_MIN RT_TABLE_MAIN 400 #define FIB6_TABLE_MAX FIB6_TABLE_MIN 401 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN 402 #endif 403 404 typedef struct rt6_info *(*pol_lookup_t)(struct net *, 405 struct fib6_table *, 406 struct flowi6 *, 407 const struct sk_buff *, int); 408 409 struct fib6_entry_notifier_info { 410 struct fib_notifier_info info; /* must be first */ 411 struct fib6_info *rt; 412 unsigned int nsiblings; 413 }; 414 415 /* 416 * exported functions 417 */ 418 419 struct fib6_table *fib6_get_table(struct net *net, u32 id); 420 struct fib6_table *fib6_new_table(struct net *net, u32 id); 421 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 422 const struct sk_buff *skb, 423 int flags, pol_lookup_t lookup); 424 425 /* called with rcu lock held; can return error pointer 426 * caller needs to select path 427 */ 428 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, 429 struct fib6_result *res, int flags); 430 431 /* called with rcu lock held; caller needs to select path */ 432 int fib6_table_lookup(struct net *net, struct fib6_table *table, 433 int oif, struct flowi6 *fl6, struct fib6_result *res, 434 int strict); 435 436 void fib6_select_path(const struct net *net, struct fib6_result *res, 437 struct flowi6 *fl6, int oif, bool have_oif_match, 438 const struct sk_buff *skb, int strict); 439 struct fib6_node *fib6_node_lookup(struct fib6_node *root, 440 const struct in6_addr *daddr, 441 const struct in6_addr *saddr); 442 443 struct fib6_node *fib6_locate(struct fib6_node *root, 444 const struct in6_addr *daddr, int dst_len, 445 const struct in6_addr *saddr, int src_len, 446 bool exact_match); 447 448 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg), 449 void *arg); 450 void fib6_clean_all_skip_notify(struct net *net, 451 int (*func)(struct fib6_info *, void *arg), 452 void *arg); 453 454 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 455 struct nl_info *info, struct netlink_ext_ack *extack); 456 int fib6_del(struct fib6_info *rt, struct nl_info *info); 457 458 static inline 459 void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr) 460 { 461 const struct fib6_info *from; 462 463 rcu_read_lock(); 464 465 from = rcu_dereference(rt->from); 466 if (from) 467 *addr = from->fib6_prefsrc.addr; 468 else 469 *addr = in6addr_any; 470 471 rcu_read_unlock(); 472 } 473 474 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh, 475 struct fib6_config *cfg, gfp_t gfp_flags, 476 struct netlink_ext_ack *extack); 477 void fib6_nh_release(struct fib6_nh *fib6_nh); 478 void fib6_nh_release_dsts(struct fib6_nh *fib6_nh); 479 480 int call_fib6_entry_notifiers(struct net *net, 481 enum fib_event_type event_type, 482 struct fib6_info *rt, 483 struct netlink_ext_ack *extack); 484 int call_fib6_multipath_entry_notifiers(struct net *net, 485 enum fib_event_type event_type, 486 struct fib6_info *rt, 487 unsigned int nsiblings, 488 struct netlink_ext_ack *extack); 489 int call_fib6_entry_notifiers_replace(struct net *net, struct fib6_info *rt); 490 void fib6_rt_update(struct net *net, struct fib6_info *rt, 491 struct nl_info *info); 492 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info, 493 unsigned int flags); 494 495 void fib6_run_gc(unsigned long expires, struct net *net, bool force); 496 497 void fib6_gc_cleanup(void); 498 499 int fib6_init(void); 500 501 struct ipv6_route_iter { 502 struct seq_net_private p; 503 struct fib6_walker w; 504 loff_t skip; 505 struct fib6_table *tbl; 506 int sernum; 507 }; 508 509 extern const struct seq_operations ipv6_route_seq_ops; 510 511 int call_fib6_notifier(struct notifier_block *nb, 512 enum fib_event_type event_type, 513 struct fib_notifier_info *info); 514 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type, 515 struct fib_notifier_info *info); 516 517 int __net_init fib6_notifier_init(struct net *net); 518 void __net_exit fib6_notifier_exit(struct net *net); 519 520 unsigned int fib6_tables_seq_read(struct net *net); 521 int fib6_tables_dump(struct net *net, struct notifier_block *nb, 522 struct netlink_ext_ack *extack); 523 524 void fib6_update_sernum(struct net *net, struct fib6_info *rt); 525 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt); 526 void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i); 527 528 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val); 529 static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric) 530 { 531 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric)); 532 } 533 void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i, 534 bool offload, bool trap, bool offload_failed); 535 536 #if IS_BUILTIN(CONFIG_IPV6) && defined(CONFIG_BPF_SYSCALL) 537 struct bpf_iter__ipv6_route { 538 __bpf_md_ptr(struct bpf_iter_meta *, meta); 539 __bpf_md_ptr(struct fib6_info *, rt); 540 }; 541 #endif 542 543 INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_output(struct net *net, 544 struct fib6_table *table, 545 struct flowi6 *fl6, 546 const struct sk_buff *skb, 547 int flags)); 548 INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_input(struct net *net, 549 struct fib6_table *table, 550 struct flowi6 *fl6, 551 const struct sk_buff *skb, 552 int flags)); 553 INDIRECT_CALLABLE_DECLARE(struct rt6_info *__ip6_route_redirect(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_lookup(struct net *net, 559 struct fib6_table *table, 560 struct flowi6 *fl6, 561 const struct sk_buff *skb, 562 int flags)); 563 static inline struct rt6_info *pol_lookup_func(pol_lookup_t lookup, 564 struct net *net, 565 struct fib6_table *table, 566 struct flowi6 *fl6, 567 const struct sk_buff *skb, 568 int flags) 569 { 570 return INDIRECT_CALL_4(lookup, 571 ip6_pol_route_output, 572 ip6_pol_route_input, 573 ip6_pol_route_lookup, 574 __ip6_route_redirect, 575 net, table, fl6, skb, flags); 576 } 577 578 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 579 static inline bool fib6_has_custom_rules(const struct net *net) 580 { 581 return net->ipv6.fib6_has_custom_rules; 582 } 583 584 int fib6_rules_init(void); 585 void fib6_rules_cleanup(void); 586 bool fib6_rule_default(const struct fib_rule *rule); 587 int fib6_rules_dump(struct net *net, struct notifier_block *nb, 588 struct netlink_ext_ack *extack); 589 unsigned int fib6_rules_seq_read(struct net *net); 590 591 static inline bool fib6_rules_early_flow_dissect(struct net *net, 592 struct sk_buff *skb, 593 struct flowi6 *fl6, 594 struct flow_keys *flkeys) 595 { 596 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 597 598 if (!net->ipv6.fib6_rules_require_fldissect) 599 return false; 600 601 memset(flkeys, 0, sizeof(*flkeys)); 602 __skb_flow_dissect(net, skb, &flow_keys_dissector, 603 flkeys, NULL, 0, 0, 0, flag); 604 605 fl6->fl6_sport = flkeys->ports.src; 606 fl6->fl6_dport = flkeys->ports.dst; 607 fl6->flowi6_proto = flkeys->basic.ip_proto; 608 609 return true; 610 } 611 #else 612 static inline bool fib6_has_custom_rules(const struct net *net) 613 { 614 return false; 615 } 616 static inline int fib6_rules_init(void) 617 { 618 return 0; 619 } 620 static inline void fib6_rules_cleanup(void) 621 { 622 return ; 623 } 624 static inline bool fib6_rule_default(const struct fib_rule *rule) 625 { 626 return true; 627 } 628 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb, 629 struct netlink_ext_ack *extack) 630 { 631 return 0; 632 } 633 static inline unsigned int fib6_rules_seq_read(struct net *net) 634 { 635 return 0; 636 } 637 static inline bool fib6_rules_early_flow_dissect(struct net *net, 638 struct sk_buff *skb, 639 struct flowi6 *fl6, 640 struct flow_keys *flkeys) 641 { 642 return false; 643 } 644 #endif 645 #endif 646