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 unused:3; 196 197 struct rcu_head rcu; 198 struct nexthop *nh; 199 struct fib6_nh fib6_nh[0]; 200 }; 201 202 struct rt6_info { 203 struct dst_entry dst; 204 struct fib6_info __rcu *from; 205 206 struct rt6key rt6i_dst; 207 struct rt6key rt6i_src; 208 struct in6_addr rt6i_gateway; 209 struct inet6_dev *rt6i_idev; 210 u32 rt6i_flags; 211 212 struct list_head rt6i_uncached; 213 struct uncached_list *rt6i_uncached_list; 214 215 /* more non-fragment space at head required */ 216 unsigned short rt6i_nfheader_len; 217 }; 218 219 struct fib6_result { 220 struct fib6_nh *nh; 221 struct fib6_info *f6i; 222 u32 fib6_flags; 223 u8 fib6_type; 224 struct rt6_info *rt6; 225 }; 226 227 #define for_each_fib6_node_rt_rcu(fn) \ 228 for (rt = rcu_dereference((fn)->leaf); rt; \ 229 rt = rcu_dereference(rt->fib6_next)) 230 231 #define for_each_fib6_walker_rt(w) \ 232 for (rt = (w)->leaf; rt; \ 233 rt = rcu_dereference_protected(rt->fib6_next, 1)) 234 235 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst) 236 { 237 return ((struct rt6_info *)dst)->rt6i_idev; 238 } 239 240 static inline bool fib6_requires_src(const struct fib6_info *rt) 241 { 242 return rt->fib6_src.plen > 0; 243 } 244 245 static inline void fib6_clean_expires(struct fib6_info *f6i) 246 { 247 f6i->fib6_flags &= ~RTF_EXPIRES; 248 f6i->expires = 0; 249 } 250 251 static inline void fib6_set_expires(struct fib6_info *f6i, 252 unsigned long expires) 253 { 254 f6i->expires = expires; 255 f6i->fib6_flags |= RTF_EXPIRES; 256 } 257 258 static inline bool fib6_check_expired(const struct fib6_info *f6i) 259 { 260 if (f6i->fib6_flags & RTF_EXPIRES) 261 return time_after(jiffies, f6i->expires); 262 return false; 263 } 264 265 /* Function to safely get fn->sernum for passed in rt 266 * and store result in passed in cookie. 267 * Return true if we can get cookie safely 268 * Return false if not 269 */ 270 static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i, 271 u32 *cookie) 272 { 273 struct fib6_node *fn; 274 bool status = false; 275 276 fn = rcu_dereference(f6i->fib6_node); 277 278 if (fn) { 279 *cookie = fn->fn_sernum; 280 /* pairs with smp_wmb() in fib6_update_sernum_upto_root() */ 281 smp_rmb(); 282 status = true; 283 } 284 285 return status; 286 } 287 288 static inline u32 rt6_get_cookie(const struct rt6_info *rt) 289 { 290 struct fib6_info *from; 291 u32 cookie = 0; 292 293 rcu_read_lock(); 294 295 from = rcu_dereference(rt->from); 296 if (from) 297 fib6_get_cookie_safe(from, &cookie); 298 299 rcu_read_unlock(); 300 301 return cookie; 302 } 303 304 static inline void ip6_rt_put(struct rt6_info *rt) 305 { 306 /* dst_release() accepts a NULL parameter. 307 * We rely on dst being first structure in struct rt6_info 308 */ 309 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0); 310 dst_release(&rt->dst); 311 } 312 313 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh); 314 void fib6_info_destroy_rcu(struct rcu_head *head); 315 316 static inline void fib6_info_hold(struct fib6_info *f6i) 317 { 318 refcount_inc(&f6i->fib6_ref); 319 } 320 321 static inline bool fib6_info_hold_safe(struct fib6_info *f6i) 322 { 323 return refcount_inc_not_zero(&f6i->fib6_ref); 324 } 325 326 static inline void fib6_info_release(struct fib6_info *f6i) 327 { 328 if (f6i && refcount_dec_and_test(&f6i->fib6_ref)) 329 call_rcu(&f6i->rcu, fib6_info_destroy_rcu); 330 } 331 332 enum fib6_walk_state { 333 #ifdef CONFIG_IPV6_SUBTREES 334 FWS_S, 335 #endif 336 FWS_L, 337 FWS_R, 338 FWS_C, 339 FWS_U 340 }; 341 342 struct fib6_walker { 343 struct list_head lh; 344 struct fib6_node *root, *node; 345 struct fib6_info *leaf; 346 enum fib6_walk_state state; 347 unsigned int skip; 348 unsigned int count; 349 unsigned int skip_in_node; 350 int (*func)(struct fib6_walker *); 351 void *args; 352 }; 353 354 struct rt6_statistics { 355 __u32 fib_nodes; /* all fib6 nodes */ 356 __u32 fib_route_nodes; /* intermediate nodes */ 357 __u32 fib_rt_entries; /* rt entries in fib table */ 358 __u32 fib_rt_cache; /* cached rt entries in exception table */ 359 __u32 fib_discarded_routes; /* total number of routes delete */ 360 361 /* The following stats are not protected by any lock */ 362 atomic_t fib_rt_alloc; /* total number of routes alloced */ 363 atomic_t fib_rt_uncache; /* rt entries in uncached list */ 364 }; 365 366 #define RTN_TL_ROOT 0x0001 367 #define RTN_ROOT 0x0002 /* tree root node */ 368 #define RTN_RTINFO 0x0004 /* node with valid routing info */ 369 370 /* 371 * priority levels (or metrics) 372 * 373 */ 374 375 376 struct fib6_table { 377 struct hlist_node tb6_hlist; 378 u32 tb6_id; 379 spinlock_t tb6_lock; 380 struct fib6_node tb6_root; 381 struct inet_peer_base tb6_peers; 382 unsigned int flags; 383 unsigned int fib_seq; 384 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0) 385 }; 386 387 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC 388 #define RT6_TABLE_MAIN RT_TABLE_MAIN 389 #define RT6_TABLE_DFLT RT6_TABLE_MAIN 390 #define RT6_TABLE_INFO RT6_TABLE_MAIN 391 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN 392 393 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 394 #define FIB6_TABLE_MIN 1 395 #define FIB6_TABLE_MAX RT_TABLE_MAX 396 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL 397 #else 398 #define FIB6_TABLE_MIN RT_TABLE_MAIN 399 #define FIB6_TABLE_MAX FIB6_TABLE_MIN 400 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN 401 #endif 402 403 typedef struct rt6_info *(*pol_lookup_t)(struct net *, 404 struct fib6_table *, 405 struct flowi6 *, 406 const struct sk_buff *, int); 407 408 struct fib6_entry_notifier_info { 409 struct fib_notifier_info info; /* must be first */ 410 struct fib6_info *rt; 411 unsigned int nsiblings; 412 }; 413 414 /* 415 * exported functions 416 */ 417 418 struct fib6_table *fib6_get_table(struct net *net, u32 id); 419 struct fib6_table *fib6_new_table(struct net *net, u32 id); 420 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 421 const struct sk_buff *skb, 422 int flags, pol_lookup_t lookup); 423 424 /* called with rcu lock held; can return error pointer 425 * caller needs to select path 426 */ 427 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, 428 struct fib6_result *res, int flags); 429 430 /* called with rcu lock held; caller needs to select path */ 431 int fib6_table_lookup(struct net *net, struct fib6_table *table, 432 int oif, struct flowi6 *fl6, struct fib6_result *res, 433 int strict); 434 435 void fib6_select_path(const struct net *net, struct fib6_result *res, 436 struct flowi6 *fl6, int oif, bool have_oif_match, 437 const struct sk_buff *skb, int strict); 438 struct fib6_node *fib6_node_lookup(struct fib6_node *root, 439 const struct in6_addr *daddr, 440 const struct in6_addr *saddr); 441 442 struct fib6_node *fib6_locate(struct fib6_node *root, 443 const struct in6_addr *daddr, int dst_len, 444 const struct in6_addr *saddr, int src_len, 445 bool exact_match); 446 447 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg), 448 void *arg); 449 void fib6_clean_all_skip_notify(struct net *net, 450 int (*func)(struct fib6_info *, void *arg), 451 void *arg); 452 453 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 454 struct nl_info *info, struct netlink_ext_ack *extack); 455 int fib6_del(struct fib6_info *rt, struct nl_info *info); 456 457 static inline 458 void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr) 459 { 460 const struct fib6_info *from; 461 462 rcu_read_lock(); 463 464 from = rcu_dereference(rt->from); 465 if (from) { 466 *addr = from->fib6_prefsrc.addr; 467 } else { 468 struct in6_addr in6_zero = {}; 469 470 *addr = in6_zero; 471 } 472 473 rcu_read_unlock(); 474 } 475 476 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh, 477 struct fib6_config *cfg, gfp_t gfp_flags, 478 struct netlink_ext_ack *extack); 479 void fib6_nh_release(struct fib6_nh *fib6_nh); 480 481 int call_fib6_entry_notifiers(struct net *net, 482 enum fib_event_type event_type, 483 struct fib6_info *rt, 484 struct netlink_ext_ack *extack); 485 int call_fib6_multipath_entry_notifiers(struct net *net, 486 enum fib_event_type event_type, 487 struct fib6_info *rt, 488 unsigned int nsiblings, 489 struct netlink_ext_ack *extack); 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 } 533 534 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 535 static inline bool fib6_has_custom_rules(const struct net *net) 536 { 537 return net->ipv6.fib6_has_custom_rules; 538 } 539 540 int fib6_rules_init(void); 541 void fib6_rules_cleanup(void); 542 bool fib6_rule_default(const struct fib_rule *rule); 543 int fib6_rules_dump(struct net *net, struct notifier_block *nb, 544 struct netlink_ext_ack *extack); 545 unsigned int fib6_rules_seq_read(struct net *net); 546 547 static inline bool fib6_rules_early_flow_dissect(struct net *net, 548 struct sk_buff *skb, 549 struct flowi6 *fl6, 550 struct flow_keys *flkeys) 551 { 552 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 553 554 if (!net->ipv6.fib6_rules_require_fldissect) 555 return false; 556 557 skb_flow_dissect_flow_keys(skb, flkeys, flag); 558 fl6->fl6_sport = flkeys->ports.src; 559 fl6->fl6_dport = flkeys->ports.dst; 560 fl6->flowi6_proto = flkeys->basic.ip_proto; 561 562 return true; 563 } 564 #else 565 static inline bool fib6_has_custom_rules(const struct net *net) 566 { 567 return false; 568 } 569 static inline int fib6_rules_init(void) 570 { 571 return 0; 572 } 573 static inline void fib6_rules_cleanup(void) 574 { 575 return ; 576 } 577 static inline bool fib6_rule_default(const struct fib_rule *rule) 578 { 579 return true; 580 } 581 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb, 582 struct netlink_ext_ack *extack) 583 { 584 return 0; 585 } 586 static inline unsigned int fib6_rules_seq_read(struct net *net) 587 { 588 return 0; 589 } 590 static inline bool fib6_rules_early_flow_dissect(struct net *net, 591 struct sk_buff *skb, 592 struct flowi6 *fl6, 593 struct flow_keys *flkeys) 594 { 595 return false; 596 } 597 #endif 598 #endif 599