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 }; 69 70 struct fib6_node { 71 struct fib6_node __rcu *parent; 72 struct fib6_node __rcu *left; 73 struct fib6_node __rcu *right; 74 #ifdef CONFIG_IPV6_SUBTREES 75 struct fib6_node __rcu *subtree; 76 #endif 77 struct fib6_info __rcu *leaf; 78 79 __u16 fn_bit; /* bit key */ 80 __u16 fn_flags; 81 int fn_sernum; 82 struct fib6_info __rcu *rr_ptr; 83 struct rcu_head rcu; 84 }; 85 86 struct fib6_gc_args { 87 int timeout; 88 int more; 89 }; 90 91 #ifndef CONFIG_IPV6_SUBTREES 92 #define FIB6_SUBTREE(fn) NULL 93 94 static inline bool fib6_routes_require_src(const struct net *net) 95 { 96 return false; 97 } 98 99 static inline void fib6_routes_require_src_inc(struct net *net) {} 100 static inline void fib6_routes_require_src_dec(struct net *net) {} 101 102 #else 103 104 static inline bool fib6_routes_require_src(const struct net *net) 105 { 106 return net->ipv6.fib6_routes_require_src > 0; 107 } 108 109 static inline void fib6_routes_require_src_inc(struct net *net) 110 { 111 net->ipv6.fib6_routes_require_src++; 112 } 113 114 static inline void fib6_routes_require_src_dec(struct net *net) 115 { 116 net->ipv6.fib6_routes_require_src--; 117 } 118 119 #define FIB6_SUBTREE(fn) (rcu_dereference_protected((fn)->subtree, 1)) 120 #endif 121 122 /* 123 * routing information 124 * 125 */ 126 127 struct rt6key { 128 struct in6_addr addr; 129 int plen; 130 }; 131 132 struct fib6_table; 133 134 struct rt6_exception_bucket { 135 struct hlist_head chain; 136 int depth; 137 }; 138 139 struct rt6_exception { 140 struct hlist_node hlist; 141 struct rt6_info *rt6i; 142 unsigned long stamp; 143 struct rcu_head rcu; 144 }; 145 146 #define FIB6_EXCEPTION_BUCKET_SIZE_SHIFT 10 147 #define FIB6_EXCEPTION_BUCKET_SIZE (1 << FIB6_EXCEPTION_BUCKET_SIZE_SHIFT) 148 #define FIB6_MAX_DEPTH 5 149 150 struct fib6_nh { 151 struct fib_nh_common nh_common; 152 153 #ifdef CONFIG_IPV6_ROUTER_PREF 154 unsigned long last_probe; 155 #endif 156 157 struct rt6_info * __percpu *rt6i_pcpu; 158 struct rt6_exception_bucket __rcu *rt6i_exception_bucket; 159 }; 160 161 struct fib6_info { 162 struct fib6_table *fib6_table; 163 struct fib6_info __rcu *fib6_next; 164 struct fib6_node __rcu *fib6_node; 165 166 /* Multipath routes: 167 * siblings is a list of fib6_info that have the the same metric/weight, 168 * destination, but not the same gateway. nsiblings is just a cache 169 * to speed up lookup. 170 */ 171 union { 172 struct list_head fib6_siblings; 173 struct list_head nh_list; 174 }; 175 unsigned int fib6_nsiblings; 176 177 refcount_t fib6_ref; 178 unsigned long expires; 179 struct dst_metrics *fib6_metrics; 180 #define fib6_pmtu fib6_metrics->metrics[RTAX_MTU-1] 181 182 struct rt6key fib6_dst; 183 u32 fib6_flags; 184 struct rt6key fib6_src; 185 struct rt6key fib6_prefsrc; 186 187 u32 fib6_metric; 188 u8 fib6_protocol; 189 u8 fib6_type; 190 u8 should_flush:1, 191 dst_nocount:1, 192 dst_nopolicy:1, 193 fib6_destroying:1, 194 offload:1, 195 trap:1, 196 unused:2; 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; 206 207 struct rt6key rt6i_dst; 208 struct rt6key rt6i_src; 209 struct in6_addr rt6i_gateway; 210 struct inet6_dev *rt6i_idev; 211 u32 rt6i_flags; 212 213 struct list_head rt6i_uncached; 214 struct uncached_list *rt6i_uncached_list; 215 216 /* more non-fragment space at head required */ 217 unsigned short rt6i_nfheader_len; 218 }; 219 220 struct fib6_result { 221 struct fib6_nh *nh; 222 struct fib6_info *f6i; 223 u32 fib6_flags; 224 u8 fib6_type; 225 struct rt6_info *rt6; 226 }; 227 228 #define for_each_fib6_node_rt_rcu(fn) \ 229 for (rt = rcu_dereference((fn)->leaf); rt; \ 230 rt = rcu_dereference(rt->fib6_next)) 231 232 #define for_each_fib6_walker_rt(w) \ 233 for (rt = (w)->leaf; rt; \ 234 rt = rcu_dereference_protected(rt->fib6_next, 1)) 235 236 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst) 237 { 238 return ((struct rt6_info *)dst)->rt6i_idev; 239 } 240 241 static inline bool fib6_requires_src(const struct fib6_info *rt) 242 { 243 return rt->fib6_src.plen > 0; 244 } 245 246 static inline void fib6_clean_expires(struct fib6_info *f6i) 247 { 248 f6i->fib6_flags &= ~RTF_EXPIRES; 249 f6i->expires = 0; 250 } 251 252 static inline void fib6_set_expires(struct fib6_info *f6i, 253 unsigned long expires) 254 { 255 f6i->expires = expires; 256 f6i->fib6_flags |= RTF_EXPIRES; 257 } 258 259 static inline bool fib6_check_expired(const struct fib6_info *f6i) 260 { 261 if (f6i->fib6_flags & RTF_EXPIRES) 262 return time_after(jiffies, f6i->expires); 263 return false; 264 } 265 266 /* Function to safely get fn->sernum for passed in rt 267 * and store result in passed in cookie. 268 * Return true if we can get cookie safely 269 * Return false if not 270 */ 271 static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i, 272 u32 *cookie) 273 { 274 struct fib6_node *fn; 275 bool status = false; 276 277 fn = rcu_dereference(f6i->fib6_node); 278 279 if (fn) { 280 *cookie = fn->fn_sernum; 281 /* pairs with smp_wmb() in fib6_update_sernum_upto_root() */ 282 smp_rmb(); 283 status = true; 284 } 285 286 return status; 287 } 288 289 static inline u32 rt6_get_cookie(const struct rt6_info *rt) 290 { 291 struct fib6_info *from; 292 u32 cookie = 0; 293 294 rcu_read_lock(); 295 296 from = rcu_dereference(rt->from); 297 if (from) 298 fib6_get_cookie_safe(from, &cookie); 299 300 rcu_read_unlock(); 301 302 return cookie; 303 } 304 305 static inline void ip6_rt_put(struct rt6_info *rt) 306 { 307 /* dst_release() accepts a NULL parameter. 308 * We rely on dst being first structure in struct rt6_info 309 */ 310 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0); 311 dst_release(&rt->dst); 312 } 313 314 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh); 315 void fib6_info_destroy_rcu(struct rcu_head *head); 316 317 static inline void fib6_info_hold(struct fib6_info *f6i) 318 { 319 refcount_inc(&f6i->fib6_ref); 320 } 321 322 static inline bool fib6_info_hold_safe(struct fib6_info *f6i) 323 { 324 return refcount_inc_not_zero(&f6i->fib6_ref); 325 } 326 327 static inline void fib6_info_release(struct fib6_info *f6i) 328 { 329 if (f6i && refcount_dec_and_test(&f6i->fib6_ref)) 330 call_rcu(&f6i->rcu, fib6_info_destroy_rcu); 331 } 332 333 static inline void fib6_info_hw_flags_set(struct fib6_info *f6i, bool offload, 334 bool trap) 335 { 336 f6i->offload = offload; 337 f6i->trap = trap; 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); 488 489 int call_fib6_entry_notifiers(struct net *net, 490 enum fib_event_type event_type, 491 struct fib6_info *rt, 492 struct netlink_ext_ack *extack); 493 int call_fib6_multipath_entry_notifiers(struct net *net, 494 enum fib_event_type event_type, 495 struct fib6_info *rt, 496 unsigned int nsiblings, 497 struct netlink_ext_ack *extack); 498 int call_fib6_entry_notifiers_replace(struct net *net, struct fib6_info *rt); 499 void fib6_rt_update(struct net *net, struct fib6_info *rt, 500 struct nl_info *info); 501 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info, 502 unsigned int flags); 503 504 void fib6_run_gc(unsigned long expires, struct net *net, bool force); 505 506 void fib6_gc_cleanup(void); 507 508 int fib6_init(void); 509 510 struct ipv6_route_iter { 511 struct seq_net_private p; 512 struct fib6_walker w; 513 loff_t skip; 514 struct fib6_table *tbl; 515 int sernum; 516 }; 517 518 extern const struct seq_operations ipv6_route_seq_ops; 519 520 int call_fib6_notifier(struct notifier_block *nb, 521 enum fib_event_type event_type, 522 struct fib_notifier_info *info); 523 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type, 524 struct fib_notifier_info *info); 525 526 int __net_init fib6_notifier_init(struct net *net); 527 void __net_exit fib6_notifier_exit(struct net *net); 528 529 unsigned int fib6_tables_seq_read(struct net *net); 530 int fib6_tables_dump(struct net *net, struct notifier_block *nb, 531 struct netlink_ext_ack *extack); 532 533 void fib6_update_sernum(struct net *net, struct fib6_info *rt); 534 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt); 535 void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i); 536 537 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val); 538 static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric) 539 { 540 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric)); 541 } 542 543 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 544 static inline bool fib6_has_custom_rules(const struct net *net) 545 { 546 return net->ipv6.fib6_has_custom_rules; 547 } 548 549 int fib6_rules_init(void); 550 void fib6_rules_cleanup(void); 551 bool fib6_rule_default(const struct fib_rule *rule); 552 int fib6_rules_dump(struct net *net, struct notifier_block *nb, 553 struct netlink_ext_ack *extack); 554 unsigned int fib6_rules_seq_read(struct net *net); 555 556 static inline bool fib6_rules_early_flow_dissect(struct net *net, 557 struct sk_buff *skb, 558 struct flowi6 *fl6, 559 struct flow_keys *flkeys) 560 { 561 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 562 563 if (!net->ipv6.fib6_rules_require_fldissect) 564 return false; 565 566 skb_flow_dissect_flow_keys(skb, flkeys, flag); 567 fl6->fl6_sport = flkeys->ports.src; 568 fl6->fl6_dport = flkeys->ports.dst; 569 fl6->flowi6_proto = flkeys->basic.ip_proto; 570 571 return true; 572 } 573 #else 574 static inline bool fib6_has_custom_rules(const struct net *net) 575 { 576 return false; 577 } 578 static inline int fib6_rules_init(void) 579 { 580 return 0; 581 } 582 static inline void fib6_rules_cleanup(void) 583 { 584 return ; 585 } 586 static inline bool fib6_rule_default(const struct fib_rule *rule) 587 { 588 return true; 589 } 590 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb, 591 struct netlink_ext_ack *extack) 592 { 593 return 0; 594 } 595 static inline unsigned int fib6_rules_seq_read(struct net *net) 596 { 597 return 0; 598 } 599 static inline bool fib6_rules_early_flow_dissect(struct net *net, 600 struct sk_buff *skb, 601 struct flowi6 *fl6, 602 struct flow_keys *flkeys) 603 { 604 return false; 605 } 606 #endif 607 #endif 608