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