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 struct fib6_result { 194 struct fib6_nh *nh; 195 struct fib6_info *f6i; 196 u32 fib6_flags; 197 u8 fib6_type; 198 }; 199 200 #define for_each_fib6_node_rt_rcu(fn) \ 201 for (rt = rcu_dereference((fn)->leaf); rt; \ 202 rt = rcu_dereference(rt->fib6_next)) 203 204 #define for_each_fib6_walker_rt(w) \ 205 for (rt = (w)->leaf; rt; \ 206 rt = rcu_dereference_protected(rt->fib6_next, 1)) 207 208 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst) 209 { 210 return ((struct rt6_info *)dst)->rt6i_idev; 211 } 212 213 static inline void fib6_clean_expires(struct fib6_info *f6i) 214 { 215 f6i->fib6_flags &= ~RTF_EXPIRES; 216 f6i->expires = 0; 217 } 218 219 static inline void fib6_set_expires(struct fib6_info *f6i, 220 unsigned long expires) 221 { 222 f6i->expires = expires; 223 f6i->fib6_flags |= RTF_EXPIRES; 224 } 225 226 static inline bool fib6_check_expired(const struct fib6_info *f6i) 227 { 228 if (f6i->fib6_flags & RTF_EXPIRES) 229 return time_after(jiffies, f6i->expires); 230 return false; 231 } 232 233 /* Function to safely get fn->sernum for passed in rt 234 * and store result in passed in cookie. 235 * Return true if we can get cookie safely 236 * Return false if not 237 */ 238 static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i, 239 u32 *cookie) 240 { 241 struct fib6_node *fn; 242 bool status = false; 243 244 fn = rcu_dereference(f6i->fib6_node); 245 246 if (fn) { 247 *cookie = fn->fn_sernum; 248 /* pairs with smp_wmb() in fib6_update_sernum_upto_root() */ 249 smp_rmb(); 250 status = true; 251 } 252 253 return status; 254 } 255 256 static inline u32 rt6_get_cookie(const struct rt6_info *rt) 257 { 258 struct fib6_info *from; 259 u32 cookie = 0; 260 261 rcu_read_lock(); 262 263 from = rcu_dereference(rt->from); 264 if (from && (rt->rt6i_flags & RTF_PCPU || 265 unlikely(!list_empty(&rt->rt6i_uncached)))) 266 fib6_get_cookie_safe(from, &cookie); 267 268 rcu_read_unlock(); 269 270 return cookie; 271 } 272 273 static inline void ip6_rt_put(struct rt6_info *rt) 274 { 275 /* dst_release() accepts a NULL parameter. 276 * We rely on dst being first structure in struct rt6_info 277 */ 278 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0); 279 dst_release(&rt->dst); 280 } 281 282 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags); 283 void fib6_info_destroy_rcu(struct rcu_head *head); 284 285 static inline void fib6_info_hold(struct fib6_info *f6i) 286 { 287 atomic_inc(&f6i->fib6_ref); 288 } 289 290 static inline bool fib6_info_hold_safe(struct fib6_info *f6i) 291 { 292 return atomic_inc_not_zero(&f6i->fib6_ref); 293 } 294 295 static inline void fib6_info_release(struct fib6_info *f6i) 296 { 297 if (f6i && atomic_dec_and_test(&f6i->fib6_ref)) 298 call_rcu(&f6i->rcu, fib6_info_destroy_rcu); 299 } 300 301 enum fib6_walk_state { 302 #ifdef CONFIG_IPV6_SUBTREES 303 FWS_S, 304 #endif 305 FWS_L, 306 FWS_R, 307 FWS_C, 308 FWS_U 309 }; 310 311 struct fib6_walker { 312 struct list_head lh; 313 struct fib6_node *root, *node; 314 struct fib6_info *leaf; 315 enum fib6_walk_state state; 316 unsigned int skip; 317 unsigned int count; 318 int (*func)(struct fib6_walker *); 319 void *args; 320 }; 321 322 struct rt6_statistics { 323 __u32 fib_nodes; /* all fib6 nodes */ 324 __u32 fib_route_nodes; /* intermediate nodes */ 325 __u32 fib_rt_entries; /* rt entries in fib table */ 326 __u32 fib_rt_cache; /* cached rt entries in exception table */ 327 __u32 fib_discarded_routes; /* total number of routes delete */ 328 329 /* The following stats are not protected by any lock */ 330 atomic_t fib_rt_alloc; /* total number of routes alloced */ 331 atomic_t fib_rt_uncache; /* rt entries in uncached list */ 332 }; 333 334 #define RTN_TL_ROOT 0x0001 335 #define RTN_ROOT 0x0002 /* tree root node */ 336 #define RTN_RTINFO 0x0004 /* node with valid routing info */ 337 338 /* 339 * priority levels (or metrics) 340 * 341 */ 342 343 344 struct fib6_table { 345 struct hlist_node tb6_hlist; 346 u32 tb6_id; 347 spinlock_t tb6_lock; 348 struct fib6_node tb6_root; 349 struct inet_peer_base tb6_peers; 350 unsigned int flags; 351 unsigned int fib_seq; 352 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0) 353 }; 354 355 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC 356 #define RT6_TABLE_MAIN RT_TABLE_MAIN 357 #define RT6_TABLE_DFLT RT6_TABLE_MAIN 358 #define RT6_TABLE_INFO RT6_TABLE_MAIN 359 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN 360 361 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 362 #define FIB6_TABLE_MIN 1 363 #define FIB6_TABLE_MAX RT_TABLE_MAX 364 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL 365 #else 366 #define FIB6_TABLE_MIN RT_TABLE_MAIN 367 #define FIB6_TABLE_MAX FIB6_TABLE_MIN 368 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN 369 #endif 370 371 typedef struct rt6_info *(*pol_lookup_t)(struct net *, 372 struct fib6_table *, 373 struct flowi6 *, 374 const struct sk_buff *, int); 375 376 struct fib6_entry_notifier_info { 377 struct fib_notifier_info info; /* must be first */ 378 struct fib6_info *rt; 379 }; 380 381 /* 382 * exported functions 383 */ 384 385 struct fib6_table *fib6_get_table(struct net *net, u32 id); 386 struct fib6_table *fib6_new_table(struct net *net, u32 id); 387 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 388 const struct sk_buff *skb, 389 int flags, pol_lookup_t lookup); 390 391 /* called with rcu lock held; can return error pointer 392 * caller needs to select path 393 */ 394 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, 395 struct fib6_result *res, int flags); 396 397 /* called with rcu lock held; caller needs to select path */ 398 int fib6_table_lookup(struct net *net, struct fib6_table *table, 399 int oif, struct flowi6 *fl6, struct fib6_result *res, 400 int strict); 401 402 void fib6_select_path(const struct net *net, struct fib6_result *res, 403 struct flowi6 *fl6, int oif, bool have_oif_match, 404 const struct sk_buff *skb, int strict); 405 struct fib6_node *fib6_node_lookup(struct fib6_node *root, 406 const struct in6_addr *daddr, 407 const struct in6_addr *saddr); 408 409 struct fib6_node *fib6_locate(struct fib6_node *root, 410 const struct in6_addr *daddr, int dst_len, 411 const struct in6_addr *saddr, int src_len, 412 bool exact_match); 413 414 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg), 415 void *arg); 416 void fib6_clean_all_skip_notify(struct net *net, 417 int (*func)(struct fib6_info *, void *arg), 418 void *arg); 419 420 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 421 struct nl_info *info, struct netlink_ext_ack *extack); 422 int fib6_del(struct fib6_info *rt, struct nl_info *info); 423 424 static inline 425 void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr) 426 { 427 const struct fib6_info *from; 428 429 rcu_read_lock(); 430 431 from = rcu_dereference(rt->from); 432 if (from) { 433 *addr = from->fib6_prefsrc.addr; 434 } else { 435 struct in6_addr in6_zero = {}; 436 437 *addr = in6_zero; 438 } 439 440 rcu_read_unlock(); 441 } 442 443 static inline struct net_device *fib6_info_nh_dev(const struct fib6_info *f6i) 444 { 445 return f6i->fib6_nh.fib_nh_dev; 446 } 447 448 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh, 449 struct fib6_config *cfg, gfp_t gfp_flags, 450 struct netlink_ext_ack *extack); 451 void fib6_nh_release(struct fib6_nh *fib6_nh); 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