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 dst_host:1, 194 fib6_destroying:1, 195 offload:1, 196 trap:1, 197 unused:1; 198 199 struct rcu_head rcu; 200 struct nexthop *nh; 201 struct fib6_nh fib6_nh[0]; 202 }; 203 204 struct rt6_info { 205 struct dst_entry dst; 206 struct fib6_info __rcu *from; 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 struct list_head rt6i_uncached; 215 struct uncached_list *rt6i_uncached_list; 216 217 /* more non-fragment space at head required */ 218 unsigned short rt6i_nfheader_len; 219 }; 220 221 struct fib6_result { 222 struct fib6_nh *nh; 223 struct fib6_info *f6i; 224 u32 fib6_flags; 225 u8 fib6_type; 226 struct rt6_info *rt6; 227 }; 228 229 #define for_each_fib6_node_rt_rcu(fn) \ 230 for (rt = rcu_dereference((fn)->leaf); rt; \ 231 rt = rcu_dereference(rt->fib6_next)) 232 233 #define for_each_fib6_walker_rt(w) \ 234 for (rt = (w)->leaf; rt; \ 235 rt = rcu_dereference_protected(rt->fib6_next, 1)) 236 237 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst) 238 { 239 return ((struct rt6_info *)dst)->rt6i_idev; 240 } 241 242 static inline bool fib6_requires_src(const struct fib6_info *rt) 243 { 244 return rt->fib6_src.plen > 0; 245 } 246 247 static inline void fib6_clean_expires(struct fib6_info *f6i) 248 { 249 f6i->fib6_flags &= ~RTF_EXPIRES; 250 f6i->expires = 0; 251 } 252 253 static inline void fib6_set_expires(struct fib6_info *f6i, 254 unsigned long expires) 255 { 256 f6i->expires = expires; 257 f6i->fib6_flags |= RTF_EXPIRES; 258 } 259 260 static inline bool fib6_check_expired(const struct fib6_info *f6i) 261 { 262 if (f6i->fib6_flags & RTF_EXPIRES) 263 return time_after(jiffies, f6i->expires); 264 return false; 265 } 266 267 /* Function to safely get fn->sernum for passed in rt 268 * and store result in passed in cookie. 269 * Return true if we can get cookie safely 270 * Return false if not 271 */ 272 static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i, 273 u32 *cookie) 274 { 275 struct fib6_node *fn; 276 bool status = false; 277 278 fn = rcu_dereference(f6i->fib6_node); 279 280 if (fn) { 281 *cookie = fn->fn_sernum; 282 /* pairs with smp_wmb() in fib6_update_sernum_upto_root() */ 283 smp_rmb(); 284 status = true; 285 } 286 287 return status; 288 } 289 290 static inline u32 rt6_get_cookie(const struct rt6_info *rt) 291 { 292 struct fib6_info *from; 293 u32 cookie = 0; 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 static inline void fib6_info_hw_flags_set(struct fib6_info *f6i, bool offload, 335 bool trap) 336 { 337 f6i->offload = offload; 338 f6i->trap = trap; 339 } 340 341 enum fib6_walk_state { 342 #ifdef CONFIG_IPV6_SUBTREES 343 FWS_S, 344 #endif 345 FWS_L, 346 FWS_R, 347 FWS_C, 348 FWS_U 349 }; 350 351 struct fib6_walker { 352 struct list_head lh; 353 struct fib6_node *root, *node; 354 struct fib6_info *leaf; 355 enum fib6_walk_state state; 356 unsigned int skip; 357 unsigned int count; 358 unsigned int skip_in_node; 359 int (*func)(struct fib6_walker *); 360 void *args; 361 }; 362 363 struct rt6_statistics { 364 __u32 fib_nodes; /* all fib6 nodes */ 365 __u32 fib_route_nodes; /* intermediate nodes */ 366 __u32 fib_rt_entries; /* rt entries in fib table */ 367 __u32 fib_rt_cache; /* cached rt entries in exception table */ 368 __u32 fib_discarded_routes; /* total number of routes delete */ 369 370 /* The following stats are not protected by any lock */ 371 atomic_t fib_rt_alloc; /* total number of routes alloced */ 372 atomic_t fib_rt_uncache; /* rt entries in uncached list */ 373 }; 374 375 #define RTN_TL_ROOT 0x0001 376 #define RTN_ROOT 0x0002 /* tree root node */ 377 #define RTN_RTINFO 0x0004 /* node with valid routing info */ 378 379 /* 380 * priority levels (or metrics) 381 * 382 */ 383 384 385 struct fib6_table { 386 struct hlist_node tb6_hlist; 387 u32 tb6_id; 388 spinlock_t tb6_lock; 389 struct fib6_node tb6_root; 390 struct inet_peer_base tb6_peers; 391 unsigned int flags; 392 unsigned int fib_seq; 393 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0) 394 }; 395 396 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC 397 #define RT6_TABLE_MAIN RT_TABLE_MAIN 398 #define RT6_TABLE_DFLT RT6_TABLE_MAIN 399 #define RT6_TABLE_INFO RT6_TABLE_MAIN 400 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN 401 402 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 403 #define FIB6_TABLE_MIN 1 404 #define FIB6_TABLE_MAX RT_TABLE_MAX 405 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL 406 #else 407 #define FIB6_TABLE_MIN RT_TABLE_MAIN 408 #define FIB6_TABLE_MAX FIB6_TABLE_MIN 409 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN 410 #endif 411 412 typedef struct rt6_info *(*pol_lookup_t)(struct net *, 413 struct fib6_table *, 414 struct flowi6 *, 415 const struct sk_buff *, int); 416 417 struct fib6_entry_notifier_info { 418 struct fib_notifier_info info; /* must be first */ 419 struct fib6_info *rt; 420 unsigned int nsiblings; 421 }; 422 423 /* 424 * exported functions 425 */ 426 427 struct fib6_table *fib6_get_table(struct net *net, u32 id); 428 struct fib6_table *fib6_new_table(struct net *net, u32 id); 429 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 430 const struct sk_buff *skb, 431 int flags, pol_lookup_t lookup); 432 433 /* called with rcu lock held; can return error pointer 434 * caller needs to select path 435 */ 436 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, 437 struct fib6_result *res, int flags); 438 439 /* called with rcu lock held; caller needs to select path */ 440 int fib6_table_lookup(struct net *net, struct fib6_table *table, 441 int oif, struct flowi6 *fl6, struct fib6_result *res, 442 int strict); 443 444 void fib6_select_path(const struct net *net, struct fib6_result *res, 445 struct flowi6 *fl6, int oif, bool have_oif_match, 446 const struct sk_buff *skb, int strict); 447 struct fib6_node *fib6_node_lookup(struct fib6_node *root, 448 const struct in6_addr *daddr, 449 const struct in6_addr *saddr); 450 451 struct fib6_node *fib6_locate(struct fib6_node *root, 452 const struct in6_addr *daddr, int dst_len, 453 const struct in6_addr *saddr, int src_len, 454 bool exact_match); 455 456 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg), 457 void *arg); 458 void fib6_clean_all_skip_notify(struct net *net, 459 int (*func)(struct fib6_info *, void *arg), 460 void *arg); 461 462 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 463 struct nl_info *info, struct netlink_ext_ack *extack); 464 int fib6_del(struct fib6_info *rt, struct nl_info *info); 465 466 static inline 467 void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr) 468 { 469 const struct fib6_info *from; 470 471 rcu_read_lock(); 472 473 from = rcu_dereference(rt->from); 474 if (from) { 475 *addr = from->fib6_prefsrc.addr; 476 } else { 477 struct in6_addr in6_zero = {}; 478 479 *addr = in6_zero; 480 } 481 482 rcu_read_unlock(); 483 } 484 485 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh, 486 struct fib6_config *cfg, gfp_t gfp_flags, 487 struct netlink_ext_ack *extack); 488 void fib6_nh_release(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 } 543 544 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 545 static inline bool fib6_has_custom_rules(const struct net *net) 546 { 547 return net->ipv6.fib6_has_custom_rules; 548 } 549 550 int fib6_rules_init(void); 551 void fib6_rules_cleanup(void); 552 bool fib6_rule_default(const struct fib_rule *rule); 553 int fib6_rules_dump(struct net *net, struct notifier_block *nb, 554 struct netlink_ext_ack *extack); 555 unsigned int fib6_rules_seq_read(struct net *net); 556 557 static inline bool fib6_rules_early_flow_dissect(struct net *net, 558 struct sk_buff *skb, 559 struct flowi6 *fl6, 560 struct flow_keys *flkeys) 561 { 562 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 563 564 if (!net->ipv6.fib6_rules_require_fldissect) 565 return false; 566 567 skb_flow_dissect_flow_keys(skb, flkeys, flag); 568 fl6->fl6_sport = flkeys->ports.src; 569 fl6->fl6_dport = flkeys->ports.dst; 570 fl6->flowi6_proto = flkeys->basic.ip_proto; 571 572 return true; 573 } 574 #else 575 static inline bool fib6_has_custom_rules(const struct net *net) 576 { 577 return false; 578 } 579 static inline int fib6_rules_init(void) 580 { 581 return 0; 582 } 583 static inline void fib6_rules_cleanup(void) 584 { 585 return ; 586 } 587 static inline bool fib6_rule_default(const struct fib_rule *rule) 588 { 589 return true; 590 } 591 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb, 592 struct netlink_ext_ack *extack) 593 { 594 return 0; 595 } 596 static inline unsigned int fib6_rules_seq_read(struct net *net) 597 { 598 return 0; 599 } 600 static inline bool fib6_rules_early_flow_dissect(struct net *net, 601 struct sk_buff *skb, 602 struct flowi6 *fl6, 603 struct flow_keys *flkeys) 604 { 605 return false; 606 } 607 #endif 608 #endif 609