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