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 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 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 if (rt->sernum) 296 return rt->sernum; 297 298 rcu_read_lock(); 299 300 from = rcu_dereference(rt->from); 301 if (from) 302 fib6_get_cookie_safe(from, &cookie); 303 304 rcu_read_unlock(); 305 306 return cookie; 307 } 308 309 static inline void ip6_rt_put(struct rt6_info *rt) 310 { 311 /* dst_release() accepts a NULL parameter. 312 * We rely on dst being first structure in struct rt6_info 313 */ 314 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0); 315 dst_release(&rt->dst); 316 } 317 318 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh); 319 void fib6_info_destroy_rcu(struct rcu_head *head); 320 321 static inline void fib6_info_hold(struct fib6_info *f6i) 322 { 323 refcount_inc(&f6i->fib6_ref); 324 } 325 326 static inline bool fib6_info_hold_safe(struct fib6_info *f6i) 327 { 328 return refcount_inc_not_zero(&f6i->fib6_ref); 329 } 330 331 static inline void fib6_info_release(struct fib6_info *f6i) 332 { 333 if (f6i && refcount_dec_and_test(&f6i->fib6_ref)) 334 call_rcu(&f6i->rcu, fib6_info_destroy_rcu); 335 } 336 337 static inline void fib6_info_hw_flags_set(struct fib6_info *f6i, bool offload, 338 bool trap) 339 { 340 f6i->offload = offload; 341 f6i->trap = trap; 342 } 343 344 enum fib6_walk_state { 345 #ifdef CONFIG_IPV6_SUBTREES 346 FWS_S, 347 #endif 348 FWS_L, 349 FWS_R, 350 FWS_C, 351 FWS_U 352 }; 353 354 struct fib6_walker { 355 struct list_head lh; 356 struct fib6_node *root, *node; 357 struct fib6_info *leaf; 358 enum fib6_walk_state state; 359 unsigned int skip; 360 unsigned int count; 361 unsigned int skip_in_node; 362 int (*func)(struct fib6_walker *); 363 void *args; 364 }; 365 366 struct rt6_statistics { 367 __u32 fib_nodes; /* all fib6 nodes */ 368 __u32 fib_route_nodes; /* intermediate nodes */ 369 __u32 fib_rt_entries; /* rt entries in fib table */ 370 __u32 fib_rt_cache; /* cached rt entries in exception table */ 371 __u32 fib_discarded_routes; /* total number of routes delete */ 372 373 /* The following stats are not protected by any lock */ 374 atomic_t fib_rt_alloc; /* total number of routes alloced */ 375 atomic_t fib_rt_uncache; /* rt entries in uncached list */ 376 }; 377 378 #define RTN_TL_ROOT 0x0001 379 #define RTN_ROOT 0x0002 /* tree root node */ 380 #define RTN_RTINFO 0x0004 /* node with valid routing info */ 381 382 /* 383 * priority levels (or metrics) 384 * 385 */ 386 387 388 struct fib6_table { 389 struct hlist_node tb6_hlist; 390 u32 tb6_id; 391 spinlock_t tb6_lock; 392 struct fib6_node tb6_root; 393 struct inet_peer_base tb6_peers; 394 unsigned int flags; 395 unsigned int fib_seq; 396 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0) 397 }; 398 399 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC 400 #define RT6_TABLE_MAIN RT_TABLE_MAIN 401 #define RT6_TABLE_DFLT RT6_TABLE_MAIN 402 #define RT6_TABLE_INFO RT6_TABLE_MAIN 403 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN 404 405 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 406 #define FIB6_TABLE_MIN 1 407 #define FIB6_TABLE_MAX RT_TABLE_MAX 408 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL 409 #else 410 #define FIB6_TABLE_MIN RT_TABLE_MAIN 411 #define FIB6_TABLE_MAX FIB6_TABLE_MIN 412 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN 413 #endif 414 415 typedef struct rt6_info *(*pol_lookup_t)(struct net *, 416 struct fib6_table *, 417 struct flowi6 *, 418 const struct sk_buff *, int); 419 420 struct fib6_entry_notifier_info { 421 struct fib_notifier_info info; /* must be first */ 422 struct fib6_info *rt; 423 unsigned int nsiblings; 424 }; 425 426 /* 427 * exported functions 428 */ 429 430 struct fib6_table *fib6_get_table(struct net *net, u32 id); 431 struct fib6_table *fib6_new_table(struct net *net, u32 id); 432 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 433 const struct sk_buff *skb, 434 int flags, pol_lookup_t lookup); 435 436 /* called with rcu lock held; can return error pointer 437 * caller needs to select path 438 */ 439 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, 440 struct fib6_result *res, int flags); 441 442 /* called with rcu lock held; caller needs to select path */ 443 int fib6_table_lookup(struct net *net, struct fib6_table *table, 444 int oif, struct flowi6 *fl6, struct fib6_result *res, 445 int strict); 446 447 void fib6_select_path(const struct net *net, struct fib6_result *res, 448 struct flowi6 *fl6, int oif, bool have_oif_match, 449 const struct sk_buff *skb, int strict); 450 struct fib6_node *fib6_node_lookup(struct fib6_node *root, 451 const struct in6_addr *daddr, 452 const struct in6_addr *saddr); 453 454 struct fib6_node *fib6_locate(struct fib6_node *root, 455 const struct in6_addr *daddr, int dst_len, 456 const struct in6_addr *saddr, int src_len, 457 bool exact_match); 458 459 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg), 460 void *arg); 461 void fib6_clean_all_skip_notify(struct net *net, 462 int (*func)(struct fib6_info *, void *arg), 463 void *arg); 464 465 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 466 struct nl_info *info, struct netlink_ext_ack *extack); 467 int fib6_del(struct fib6_info *rt, struct nl_info *info); 468 469 static inline 470 void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr) 471 { 472 const struct fib6_info *from; 473 474 rcu_read_lock(); 475 476 from = rcu_dereference(rt->from); 477 if (from) { 478 *addr = from->fib6_prefsrc.addr; 479 } else { 480 struct in6_addr in6_zero = {}; 481 482 *addr = in6_zero; 483 } 484 485 rcu_read_unlock(); 486 } 487 488 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh, 489 struct fib6_config *cfg, gfp_t gfp_flags, 490 struct netlink_ext_ack *extack); 491 void fib6_nh_release(struct fib6_nh *fib6_nh); 492 493 int call_fib6_entry_notifiers(struct net *net, 494 enum fib_event_type event_type, 495 struct fib6_info *rt, 496 struct netlink_ext_ack *extack); 497 int call_fib6_multipath_entry_notifiers(struct net *net, 498 enum fib_event_type event_type, 499 struct fib6_info *rt, 500 unsigned int nsiblings, 501 struct netlink_ext_ack *extack); 502 int call_fib6_entry_notifiers_replace(struct net *net, struct fib6_info *rt); 503 void fib6_rt_update(struct net *net, struct fib6_info *rt, 504 struct nl_info *info); 505 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info, 506 unsigned int flags); 507 508 void fib6_run_gc(unsigned long expires, struct net *net, bool force); 509 510 void fib6_gc_cleanup(void); 511 512 int fib6_init(void); 513 514 struct ipv6_route_iter { 515 struct seq_net_private p; 516 struct fib6_walker w; 517 loff_t skip; 518 struct fib6_table *tbl; 519 int sernum; 520 }; 521 522 extern const struct seq_operations ipv6_route_seq_ops; 523 524 int call_fib6_notifier(struct notifier_block *nb, 525 enum fib_event_type event_type, 526 struct fib_notifier_info *info); 527 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type, 528 struct fib_notifier_info *info); 529 530 int __net_init fib6_notifier_init(struct net *net); 531 void __net_exit fib6_notifier_exit(struct net *net); 532 533 unsigned int fib6_tables_seq_read(struct net *net); 534 int fib6_tables_dump(struct net *net, struct notifier_block *nb, 535 struct netlink_ext_ack *extack); 536 537 void fib6_update_sernum(struct net *net, struct fib6_info *rt); 538 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt); 539 void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i); 540 541 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val); 542 static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric) 543 { 544 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric)); 545 } 546 547 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 548 static inline bool fib6_has_custom_rules(const struct net *net) 549 { 550 return net->ipv6.fib6_has_custom_rules; 551 } 552 553 int fib6_rules_init(void); 554 void fib6_rules_cleanup(void); 555 bool fib6_rule_default(const struct fib_rule *rule); 556 int fib6_rules_dump(struct net *net, struct notifier_block *nb, 557 struct netlink_ext_ack *extack); 558 unsigned int fib6_rules_seq_read(struct net *net); 559 560 static inline bool fib6_rules_early_flow_dissect(struct net *net, 561 struct sk_buff *skb, 562 struct flowi6 *fl6, 563 struct flow_keys *flkeys) 564 { 565 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 566 567 if (!net->ipv6.fib6_rules_require_fldissect) 568 return false; 569 570 skb_flow_dissect_flow_keys(skb, flkeys, flag); 571 fl6->fl6_sport = flkeys->ports.src; 572 fl6->fl6_dport = flkeys->ports.dst; 573 fl6->flowi6_proto = flkeys->basic.ip_proto; 574 575 return true; 576 } 577 #else 578 static inline bool fib6_has_custom_rules(const struct net *net) 579 { 580 return false; 581 } 582 static inline int fib6_rules_init(void) 583 { 584 return 0; 585 } 586 static inline void fib6_rules_cleanup(void) 587 { 588 return ; 589 } 590 static inline bool fib6_rule_default(const struct fib_rule *rule) 591 { 592 return true; 593 } 594 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb, 595 struct netlink_ext_ack *extack) 596 { 597 return 0; 598 } 599 static inline unsigned int fib6_rules_seq_read(struct net *net) 600 { 601 return 0; 602 } 603 static inline bool fib6_rules_early_flow_dissect(struct net *net, 604 struct sk_buff *skb, 605 struct flowi6 *fl6, 606 struct flow_keys *flkeys) 607 { 608 return false; 609 } 610 #endif 611 #endif 612