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 refcount_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 fib6_destroying:1, 171 unused:2; 172 173 struct fib6_nh fib6_nh; 174 struct rcu_head rcu; 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 && (rt->rt6i_flags & RTF_PCPU || 267 unlikely(!list_empty(&rt->rt6i_uncached)))) 268 fib6_get_cookie_safe(from, &cookie); 269 270 rcu_read_unlock(); 271 272 return cookie; 273 } 274 275 static inline void ip6_rt_put(struct rt6_info *rt) 276 { 277 /* dst_release() accepts a NULL parameter. 278 * We rely on dst being first structure in struct rt6_info 279 */ 280 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0); 281 dst_release(&rt->dst); 282 } 283 284 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags); 285 void fib6_info_destroy_rcu(struct rcu_head *head); 286 287 static inline void fib6_info_hold(struct fib6_info *f6i) 288 { 289 refcount_inc(&f6i->fib6_ref); 290 } 291 292 static inline bool fib6_info_hold_safe(struct fib6_info *f6i) 293 { 294 return refcount_inc_not_zero(&f6i->fib6_ref); 295 } 296 297 static inline void fib6_info_release(struct fib6_info *f6i) 298 { 299 if (f6i && refcount_dec_and_test(&f6i->fib6_ref)) 300 call_rcu(&f6i->rcu, fib6_info_destroy_rcu); 301 } 302 303 enum fib6_walk_state { 304 #ifdef CONFIG_IPV6_SUBTREES 305 FWS_S, 306 #endif 307 FWS_L, 308 FWS_R, 309 FWS_C, 310 FWS_U 311 }; 312 313 struct fib6_walker { 314 struct list_head lh; 315 struct fib6_node *root, *node; 316 struct fib6_info *leaf; 317 enum fib6_walk_state state; 318 unsigned int skip; 319 unsigned int count; 320 int (*func)(struct fib6_walker *); 321 void *args; 322 }; 323 324 struct rt6_statistics { 325 __u32 fib_nodes; /* all fib6 nodes */ 326 __u32 fib_route_nodes; /* intermediate nodes */ 327 __u32 fib_rt_entries; /* rt entries in fib table */ 328 __u32 fib_rt_cache; /* cached rt entries in exception table */ 329 __u32 fib_discarded_routes; /* total number of routes delete */ 330 331 /* The following stats are not protected by any lock */ 332 atomic_t fib_rt_alloc; /* total number of routes alloced */ 333 atomic_t fib_rt_uncache; /* rt entries in uncached list */ 334 }; 335 336 #define RTN_TL_ROOT 0x0001 337 #define RTN_ROOT 0x0002 /* tree root node */ 338 #define RTN_RTINFO 0x0004 /* node with valid routing info */ 339 340 /* 341 * priority levels (or metrics) 342 * 343 */ 344 345 346 struct fib6_table { 347 struct hlist_node tb6_hlist; 348 u32 tb6_id; 349 spinlock_t tb6_lock; 350 struct fib6_node tb6_root; 351 struct inet_peer_base tb6_peers; 352 unsigned int flags; 353 unsigned int fib_seq; 354 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0) 355 }; 356 357 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC 358 #define RT6_TABLE_MAIN RT_TABLE_MAIN 359 #define RT6_TABLE_DFLT RT6_TABLE_MAIN 360 #define RT6_TABLE_INFO RT6_TABLE_MAIN 361 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN 362 363 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 364 #define FIB6_TABLE_MIN 1 365 #define FIB6_TABLE_MAX RT_TABLE_MAX 366 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL 367 #else 368 #define FIB6_TABLE_MIN RT_TABLE_MAIN 369 #define FIB6_TABLE_MAX FIB6_TABLE_MIN 370 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN 371 #endif 372 373 typedef struct rt6_info *(*pol_lookup_t)(struct net *, 374 struct fib6_table *, 375 struct flowi6 *, 376 const struct sk_buff *, int); 377 378 struct fib6_entry_notifier_info { 379 struct fib_notifier_info info; /* must be first */ 380 struct fib6_info *rt; 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 static inline struct net_device *fib6_info_nh_dev(const struct fib6_info *f6i) 446 { 447 return f6i->fib6_nh.fib_nh_dev; 448 } 449 450 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh, 451 struct fib6_config *cfg, gfp_t gfp_flags, 452 struct netlink_ext_ack *extack); 453 void fib6_nh_release(struct fib6_nh *fib6_nh); 454 455 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info, 456 unsigned int flags); 457 458 void fib6_run_gc(unsigned long expires, struct net *net, bool force); 459 460 void fib6_gc_cleanup(void); 461 462 int fib6_init(void); 463 464 struct ipv6_route_iter { 465 struct seq_net_private p; 466 struct fib6_walker w; 467 loff_t skip; 468 struct fib6_table *tbl; 469 int sernum; 470 }; 471 472 extern const struct seq_operations ipv6_route_seq_ops; 473 474 int call_fib6_notifier(struct notifier_block *nb, struct net *net, 475 enum fib_event_type event_type, 476 struct fib_notifier_info *info); 477 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type, 478 struct fib_notifier_info *info); 479 480 int __net_init fib6_notifier_init(struct net *net); 481 void __net_exit fib6_notifier_exit(struct net *net); 482 483 unsigned int fib6_tables_seq_read(struct net *net); 484 int fib6_tables_dump(struct net *net, struct notifier_block *nb); 485 486 void fib6_update_sernum(struct net *net, struct fib6_info *rt); 487 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt); 488 489 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val); 490 static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric) 491 { 492 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric)); 493 } 494 495 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 496 int fib6_rules_init(void); 497 void fib6_rules_cleanup(void); 498 bool fib6_rule_default(const struct fib_rule *rule); 499 int fib6_rules_dump(struct net *net, struct notifier_block *nb); 500 unsigned int fib6_rules_seq_read(struct net *net); 501 502 static inline bool fib6_rules_early_flow_dissect(struct net *net, 503 struct sk_buff *skb, 504 struct flowi6 *fl6, 505 struct flow_keys *flkeys) 506 { 507 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 508 509 if (!net->ipv6.fib6_rules_require_fldissect) 510 return false; 511 512 skb_flow_dissect_flow_keys(skb, flkeys, flag); 513 fl6->fl6_sport = flkeys->ports.src; 514 fl6->fl6_dport = flkeys->ports.dst; 515 fl6->flowi6_proto = flkeys->basic.ip_proto; 516 517 return true; 518 } 519 #else 520 static inline int fib6_rules_init(void) 521 { 522 return 0; 523 } 524 static inline void fib6_rules_cleanup(void) 525 { 526 return ; 527 } 528 static inline bool fib6_rule_default(const struct fib_rule *rule) 529 { 530 return true; 531 } 532 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb) 533 { 534 return 0; 535 } 536 static inline unsigned int fib6_rules_seq_read(struct net *net) 537 { 538 return 0; 539 } 540 static inline bool fib6_rules_early_flow_dissect(struct net *net, 541 struct sk_buff *skb, 542 struct flowi6 *fl6, 543 struct flow_keys *flkeys) 544 { 545 return false; 546 } 547 #endif 548 #endif 549