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