1 /* 2 * Linux INET6 implementation 3 * 4 * Authors: 5 * Pedro Roque <roque@di.fc.ul.pt> 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 10 * 2 of the License, or (at your option) any later version. 11 */ 12 13 #ifndef _IP6_FIB_H 14 #define _IP6_FIB_H 15 16 #include <linux/ipv6_route.h> 17 #include <linux/rtnetlink.h> 18 #include <linux/spinlock.h> 19 #include <linux/notifier.h> 20 #include <net/dst.h> 21 #include <net/flow.h> 22 #include <net/ip_fib.h> 23 #include <net/netlink.h> 24 #include <net/inetpeer.h> 25 #include <net/fib_notifier.h> 26 27 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 28 #define FIB6_TABLE_HASHSZ 256 29 #else 30 #define FIB6_TABLE_HASHSZ 1 31 #endif 32 33 #define RT6_DEBUG 2 34 35 #if RT6_DEBUG >= 3 36 #define RT6_TRACE(x...) pr_debug(x) 37 #else 38 #define RT6_TRACE(x...) do { ; } while (0) 39 #endif 40 41 struct rt6_info; 42 struct fib6_info; 43 44 struct fib6_config { 45 u32 fc_table; 46 u32 fc_metric; 47 int fc_dst_len; 48 int fc_src_len; 49 int fc_ifindex; 50 u32 fc_flags; 51 u32 fc_protocol; 52 u16 fc_type; /* only 8 bits are used */ 53 u16 fc_delete_all_nh : 1, 54 fc_ignore_dev_down:1, 55 __unused : 14; 56 57 struct in6_addr fc_dst; 58 struct in6_addr fc_src; 59 struct in6_addr fc_prefsrc; 60 struct in6_addr fc_gateway; 61 62 unsigned long fc_expires; 63 struct nlattr *fc_mx; 64 int fc_mx_len; 65 int fc_mp_len; 66 struct nlattr *fc_mp; 67 68 struct nl_info fc_nlinfo; 69 struct nlattr *fc_encap; 70 u16 fc_encap_type; 71 }; 72 73 struct fib6_node { 74 struct fib6_node __rcu *parent; 75 struct fib6_node __rcu *left; 76 struct fib6_node __rcu *right; 77 #ifdef CONFIG_IPV6_SUBTREES 78 struct fib6_node __rcu *subtree; 79 #endif 80 struct fib6_info __rcu *leaf; 81 82 __u16 fn_bit; /* bit key */ 83 __u16 fn_flags; 84 int fn_sernum; 85 struct fib6_info __rcu *rr_ptr; 86 struct rcu_head rcu; 87 }; 88 89 struct fib6_gc_args { 90 int timeout; 91 int more; 92 }; 93 94 #ifndef CONFIG_IPV6_SUBTREES 95 #define FIB6_SUBTREE(fn) NULL 96 #else 97 #define FIB6_SUBTREE(fn) (rcu_dereference_protected((fn)->subtree, 1)) 98 #endif 99 100 /* 101 * routing information 102 * 103 */ 104 105 struct rt6key { 106 struct in6_addr addr; 107 int plen; 108 }; 109 110 struct fib6_table; 111 112 struct rt6_exception_bucket { 113 struct hlist_head chain; 114 int depth; 115 }; 116 117 struct rt6_exception { 118 struct hlist_node hlist; 119 struct rt6_info *rt6i; 120 unsigned long stamp; 121 struct rcu_head rcu; 122 }; 123 124 #define FIB6_EXCEPTION_BUCKET_SIZE_SHIFT 10 125 #define FIB6_EXCEPTION_BUCKET_SIZE (1 << FIB6_EXCEPTION_BUCKET_SIZE_SHIFT) 126 #define FIB6_MAX_DEPTH 5 127 128 struct fib6_nh { 129 struct fib_nh_common nh_common; 130 131 #ifdef CONFIG_IPV6_ROUTER_PREF 132 unsigned long last_probe; 133 #endif 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 struct list_head fib6_siblings; 147 unsigned int fib6_nsiblings; 148 149 atomic_t fib6_ref; 150 unsigned long expires; 151 struct dst_metrics *fib6_metrics; 152 #define fib6_pmtu fib6_metrics->metrics[RTAX_MTU-1] 153 154 struct rt6key fib6_dst; 155 u32 fib6_flags; 156 struct rt6key fib6_src; 157 struct rt6key fib6_prefsrc; 158 159 struct rt6_info * __percpu *rt6i_pcpu; 160 struct rt6_exception_bucket __rcu *rt6i_exception_bucket; 161 162 u32 fib6_metric; 163 u8 fib6_protocol; 164 u8 fib6_type; 165 u8 exception_bucket_flushed:1, 166 should_flush:1, 167 dst_nocount:1, 168 dst_nopolicy:1, 169 dst_host:1, 170 unused:3; 171 172 struct fib6_nh fib6_nh; 173 struct rcu_head rcu; 174 }; 175 176 struct rt6_info { 177 struct dst_entry dst; 178 struct fib6_info __rcu *from; 179 180 struct rt6key rt6i_dst; 181 struct rt6key rt6i_src; 182 struct in6_addr rt6i_gateway; 183 struct inet6_dev *rt6i_idev; 184 u32 rt6i_flags; 185 186 struct list_head rt6i_uncached; 187 struct uncached_list *rt6i_uncached_list; 188 189 /* more non-fragment space at head required */ 190 unsigned short rt6i_nfheader_len; 191 }; 192 193 #define for_each_fib6_node_rt_rcu(fn) \ 194 for (rt = rcu_dereference((fn)->leaf); rt; \ 195 rt = rcu_dereference(rt->fib6_next)) 196 197 #define for_each_fib6_walker_rt(w) \ 198 for (rt = (w)->leaf; rt; \ 199 rt = rcu_dereference_protected(rt->fib6_next, 1)) 200 201 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst) 202 { 203 return ((struct rt6_info *)dst)->rt6i_idev; 204 } 205 206 static inline void fib6_clean_expires(struct fib6_info *f6i) 207 { 208 f6i->fib6_flags &= ~RTF_EXPIRES; 209 f6i->expires = 0; 210 } 211 212 static inline void fib6_set_expires(struct fib6_info *f6i, 213 unsigned long expires) 214 { 215 f6i->expires = expires; 216 f6i->fib6_flags |= RTF_EXPIRES; 217 } 218 219 static inline bool fib6_check_expired(const struct fib6_info *f6i) 220 { 221 if (f6i->fib6_flags & RTF_EXPIRES) 222 return time_after(jiffies, f6i->expires); 223 return false; 224 } 225 226 /* Function to safely get fn->sernum for passed in rt 227 * and store result in passed in cookie. 228 * Return true if we can get cookie safely 229 * Return false if not 230 */ 231 static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i, 232 u32 *cookie) 233 { 234 struct fib6_node *fn; 235 bool status = false; 236 237 fn = rcu_dereference(f6i->fib6_node); 238 239 if (fn) { 240 *cookie = fn->fn_sernum; 241 /* pairs with smp_wmb() in fib6_update_sernum_upto_root() */ 242 smp_rmb(); 243 status = true; 244 } 245 246 return status; 247 } 248 249 static inline u32 rt6_get_cookie(const struct rt6_info *rt) 250 { 251 struct fib6_info *from; 252 u32 cookie = 0; 253 254 rcu_read_lock(); 255 256 from = rcu_dereference(rt->from); 257 if (from && (rt->rt6i_flags & RTF_PCPU || 258 unlikely(!list_empty(&rt->rt6i_uncached)))) 259 fib6_get_cookie_safe(from, &cookie); 260 261 rcu_read_unlock(); 262 263 return cookie; 264 } 265 266 static inline void ip6_rt_put(struct rt6_info *rt) 267 { 268 /* dst_release() accepts a NULL parameter. 269 * We rely on dst being first structure in struct rt6_info 270 */ 271 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0); 272 dst_release(&rt->dst); 273 } 274 275 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags); 276 void fib6_info_destroy_rcu(struct rcu_head *head); 277 278 static inline void fib6_info_hold(struct fib6_info *f6i) 279 { 280 atomic_inc(&f6i->fib6_ref); 281 } 282 283 static inline bool fib6_info_hold_safe(struct fib6_info *f6i) 284 { 285 return atomic_inc_not_zero(&f6i->fib6_ref); 286 } 287 288 static inline void fib6_info_release(struct fib6_info *f6i) 289 { 290 if (f6i && atomic_dec_and_test(&f6i->fib6_ref)) 291 call_rcu(&f6i->rcu, fib6_info_destroy_rcu); 292 } 293 294 enum fib6_walk_state { 295 #ifdef CONFIG_IPV6_SUBTREES 296 FWS_S, 297 #endif 298 FWS_L, 299 FWS_R, 300 FWS_C, 301 FWS_U 302 }; 303 304 struct fib6_walker { 305 struct list_head lh; 306 struct fib6_node *root, *node; 307 struct fib6_info *leaf; 308 enum fib6_walk_state state; 309 unsigned int skip; 310 unsigned int count; 311 int (*func)(struct fib6_walker *); 312 void *args; 313 }; 314 315 struct rt6_statistics { 316 __u32 fib_nodes; /* all fib6 nodes */ 317 __u32 fib_route_nodes; /* intermediate nodes */ 318 __u32 fib_rt_entries; /* rt entries in fib table */ 319 __u32 fib_rt_cache; /* cached rt entries in exception table */ 320 __u32 fib_discarded_routes; /* total number of routes delete */ 321 322 /* The following stats are not protected by any lock */ 323 atomic_t fib_rt_alloc; /* total number of routes alloced */ 324 atomic_t fib_rt_uncache; /* rt entries in uncached list */ 325 }; 326 327 #define RTN_TL_ROOT 0x0001 328 #define RTN_ROOT 0x0002 /* tree root node */ 329 #define RTN_RTINFO 0x0004 /* node with valid routing info */ 330 331 /* 332 * priority levels (or metrics) 333 * 334 */ 335 336 337 struct fib6_table { 338 struct hlist_node tb6_hlist; 339 u32 tb6_id; 340 spinlock_t tb6_lock; 341 struct fib6_node tb6_root; 342 struct inet_peer_base tb6_peers; 343 unsigned int flags; 344 unsigned int fib_seq; 345 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0) 346 }; 347 348 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC 349 #define RT6_TABLE_MAIN RT_TABLE_MAIN 350 #define RT6_TABLE_DFLT RT6_TABLE_MAIN 351 #define RT6_TABLE_INFO RT6_TABLE_MAIN 352 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN 353 354 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 355 #define FIB6_TABLE_MIN 1 356 #define FIB6_TABLE_MAX RT_TABLE_MAX 357 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL 358 #else 359 #define FIB6_TABLE_MIN RT_TABLE_MAIN 360 #define FIB6_TABLE_MAX FIB6_TABLE_MIN 361 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN 362 #endif 363 364 typedef struct rt6_info *(*pol_lookup_t)(struct net *, 365 struct fib6_table *, 366 struct flowi6 *, 367 const struct sk_buff *, int); 368 369 struct fib6_entry_notifier_info { 370 struct fib_notifier_info info; /* must be first */ 371 struct fib6_info *rt; 372 }; 373 374 /* 375 * exported functions 376 */ 377 378 struct fib6_table *fib6_get_table(struct net *net, u32 id); 379 struct fib6_table *fib6_new_table(struct net *net, u32 id); 380 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 381 const struct sk_buff *skb, 382 int flags, pol_lookup_t lookup); 383 384 /* called with rcu lock held; can return error pointer 385 * caller needs to select path 386 */ 387 struct fib6_info *fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, 388 int flags); 389 390 /* called with rcu lock held; caller needs to select path */ 391 struct fib6_info *fib6_table_lookup(struct net *net, struct fib6_table *table, 392 int oif, struct flowi6 *fl6, int strict); 393 394 struct fib6_info *fib6_multipath_select(const struct net *net, 395 struct fib6_info *match, 396 struct flowi6 *fl6, int oif, 397 const struct sk_buff *skb, int strict); 398 399 struct fib6_node *fib6_node_lookup(struct fib6_node *root, 400 const struct in6_addr *daddr, 401 const struct in6_addr *saddr); 402 403 struct fib6_node *fib6_locate(struct fib6_node *root, 404 const struct in6_addr *daddr, int dst_len, 405 const struct in6_addr *saddr, int src_len, 406 bool exact_match); 407 408 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg), 409 void *arg); 410 void fib6_clean_all_skip_notify(struct net *net, 411 int (*func)(struct fib6_info *, void *arg), 412 void *arg); 413 414 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 415 struct nl_info *info, struct netlink_ext_ack *extack); 416 int fib6_del(struct fib6_info *rt, struct nl_info *info); 417 418 static inline 419 void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr) 420 { 421 const struct fib6_info *from; 422 423 rcu_read_lock(); 424 425 from = rcu_dereference(rt->from); 426 if (from) { 427 *addr = from->fib6_prefsrc.addr; 428 } else { 429 struct in6_addr in6_zero = {}; 430 431 *addr = in6_zero; 432 } 433 434 rcu_read_unlock(); 435 } 436 437 static inline struct net_device *fib6_info_nh_dev(const struct fib6_info *f6i) 438 { 439 return f6i->fib6_nh.fib_nh_dev; 440 } 441 442 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh, 443 struct fib6_config *cfg, gfp_t gfp_flags, 444 struct netlink_ext_ack *extack); 445 void fib6_nh_release(struct fib6_nh *fib6_nh); 446 447 static inline 448 struct lwtunnel_state *fib6_info_nh_lwt(const struct fib6_info *f6i) 449 { 450 return f6i->fib6_nh.fib_nh_lws; 451 } 452 453 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info, 454 unsigned int flags); 455 456 void fib6_run_gc(unsigned long expires, struct net *net, bool force); 457 458 void fib6_gc_cleanup(void); 459 460 int fib6_init(void); 461 462 struct ipv6_route_iter { 463 struct seq_net_private p; 464 struct fib6_walker w; 465 loff_t skip; 466 struct fib6_table *tbl; 467 int sernum; 468 }; 469 470 extern const struct seq_operations ipv6_route_seq_ops; 471 472 int call_fib6_notifier(struct notifier_block *nb, struct net *net, 473 enum fib_event_type event_type, 474 struct fib_notifier_info *info); 475 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type, 476 struct fib_notifier_info *info); 477 478 int __net_init fib6_notifier_init(struct net *net); 479 void __net_exit fib6_notifier_exit(struct net *net); 480 481 unsigned int fib6_tables_seq_read(struct net *net); 482 int fib6_tables_dump(struct net *net, struct notifier_block *nb); 483 484 void fib6_update_sernum(struct net *net, struct fib6_info *rt); 485 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt); 486 487 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val); 488 static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric) 489 { 490 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric)); 491 } 492 493 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 494 int fib6_rules_init(void); 495 void fib6_rules_cleanup(void); 496 bool fib6_rule_default(const struct fib_rule *rule); 497 int fib6_rules_dump(struct net *net, struct notifier_block *nb); 498 unsigned int fib6_rules_seq_read(struct net *net); 499 500 static inline bool fib6_rules_early_flow_dissect(struct net *net, 501 struct sk_buff *skb, 502 struct flowi6 *fl6, 503 struct flow_keys *flkeys) 504 { 505 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 506 507 if (!net->ipv6.fib6_rules_require_fldissect) 508 return false; 509 510 skb_flow_dissect_flow_keys(skb, flkeys, flag); 511 fl6->fl6_sport = flkeys->ports.src; 512 fl6->fl6_dport = flkeys->ports.dst; 513 fl6->flowi6_proto = flkeys->basic.ip_proto; 514 515 return true; 516 } 517 #else 518 static inline int fib6_rules_init(void) 519 { 520 return 0; 521 } 522 static inline void fib6_rules_cleanup(void) 523 { 524 return ; 525 } 526 static inline bool fib6_rule_default(const struct fib_rule *rule) 527 { 528 return true; 529 } 530 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb) 531 { 532 return 0; 533 } 534 static inline unsigned int fib6_rules_seq_read(struct net *net) 535 { 536 return 0; 537 } 538 static inline bool fib6_rules_early_flow_dissect(struct net *net, 539 struct sk_buff *skb, 540 struct flowi6 *fl6, 541 struct flow_keys *flkeys) 542 { 543 return false; 544 } 545 #endif 546 #endif 547