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 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 struct rt6key rt6i_prefsrc; 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 #define for_each_fib6_node_rt_rcu(fn) \ 195 for (rt = rcu_dereference((fn)->leaf); rt; \ 196 rt = rcu_dereference(rt->fib6_next)) 197 198 #define for_each_fib6_walker_rt(w) \ 199 for (rt = (w)->leaf; rt; \ 200 rt = rcu_dereference_protected(rt->fib6_next, 1)) 201 202 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst) 203 { 204 return ((struct rt6_info *)dst)->rt6i_idev; 205 } 206 207 static inline void fib6_clean_expires(struct fib6_info *f6i) 208 { 209 f6i->fib6_flags &= ~RTF_EXPIRES; 210 f6i->expires = 0; 211 } 212 213 static inline void fib6_set_expires(struct fib6_info *f6i, 214 unsigned long expires) 215 { 216 f6i->expires = expires; 217 f6i->fib6_flags |= RTF_EXPIRES; 218 } 219 220 static inline bool fib6_check_expired(const struct fib6_info *f6i) 221 { 222 if (f6i->fib6_flags & RTF_EXPIRES) 223 return time_after(jiffies, f6i->expires); 224 return false; 225 } 226 227 /* Function to safely get fn->sernum for passed in rt 228 * and store result in passed in cookie. 229 * Return true if we can get cookie safely 230 * Return false if not 231 */ 232 static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i, 233 u32 *cookie) 234 { 235 struct fib6_node *fn; 236 bool status = false; 237 238 fn = rcu_dereference(f6i->fib6_node); 239 240 if (fn) { 241 *cookie = fn->fn_sernum; 242 /* pairs with smp_wmb() in fib6_update_sernum_upto_root() */ 243 smp_rmb(); 244 status = true; 245 } 246 247 return status; 248 } 249 250 static inline u32 rt6_get_cookie(const struct rt6_info *rt) 251 { 252 struct fib6_info *from; 253 u32 cookie = 0; 254 255 rcu_read_lock(); 256 257 from = rcu_dereference(rt->from); 258 if (from && (rt->rt6i_flags & RTF_PCPU || 259 unlikely(!list_empty(&rt->rt6i_uncached)))) 260 fib6_get_cookie_safe(from, &cookie); 261 262 rcu_read_unlock(); 263 264 return cookie; 265 } 266 267 static inline void ip6_rt_put(struct rt6_info *rt) 268 { 269 /* dst_release() accepts a NULL parameter. 270 * We rely on dst being first structure in struct rt6_info 271 */ 272 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0); 273 dst_release(&rt->dst); 274 } 275 276 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags); 277 void fib6_info_destroy_rcu(struct rcu_head *head); 278 279 static inline void fib6_info_hold(struct fib6_info *f6i) 280 { 281 atomic_inc(&f6i->fib6_ref); 282 } 283 284 static inline bool fib6_info_hold_safe(struct fib6_info *f6i) 285 { 286 return atomic_inc_not_zero(&f6i->fib6_ref); 287 } 288 289 static inline void fib6_info_release(struct fib6_info *f6i) 290 { 291 if (f6i && atomic_dec_and_test(&f6i->fib6_ref)) 292 call_rcu(&f6i->rcu, fib6_info_destroy_rcu); 293 } 294 295 enum fib6_walk_state { 296 #ifdef CONFIG_IPV6_SUBTREES 297 FWS_S, 298 #endif 299 FWS_L, 300 FWS_R, 301 FWS_C, 302 FWS_U 303 }; 304 305 struct fib6_walker { 306 struct list_head lh; 307 struct fib6_node *root, *node; 308 struct fib6_info *leaf; 309 enum fib6_walk_state state; 310 unsigned int skip; 311 unsigned int count; 312 int (*func)(struct fib6_walker *); 313 void *args; 314 }; 315 316 struct rt6_statistics { 317 __u32 fib_nodes; /* all fib6 nodes */ 318 __u32 fib_route_nodes; /* intermediate nodes */ 319 __u32 fib_rt_entries; /* rt entries in fib table */ 320 __u32 fib_rt_cache; /* cached rt entries in exception table */ 321 __u32 fib_discarded_routes; /* total number of routes delete */ 322 323 /* The following stats are not protected by any lock */ 324 atomic_t fib_rt_alloc; /* total number of routes alloced */ 325 atomic_t fib_rt_uncache; /* rt entries in uncached list */ 326 }; 327 328 #define RTN_TL_ROOT 0x0001 329 #define RTN_ROOT 0x0002 /* tree root node */ 330 #define RTN_RTINFO 0x0004 /* node with valid routing info */ 331 332 /* 333 * priority levels (or metrics) 334 * 335 */ 336 337 338 struct fib6_table { 339 struct hlist_node tb6_hlist; 340 u32 tb6_id; 341 spinlock_t tb6_lock; 342 struct fib6_node tb6_root; 343 struct inet_peer_base tb6_peers; 344 unsigned int flags; 345 unsigned int fib_seq; 346 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0) 347 }; 348 349 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC 350 #define RT6_TABLE_MAIN RT_TABLE_MAIN 351 #define RT6_TABLE_DFLT RT6_TABLE_MAIN 352 #define RT6_TABLE_INFO RT6_TABLE_MAIN 353 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN 354 355 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 356 #define FIB6_TABLE_MIN 1 357 #define FIB6_TABLE_MAX RT_TABLE_MAX 358 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL 359 #else 360 #define FIB6_TABLE_MIN RT_TABLE_MAIN 361 #define FIB6_TABLE_MAX FIB6_TABLE_MIN 362 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN 363 #endif 364 365 typedef struct rt6_info *(*pol_lookup_t)(struct net *, 366 struct fib6_table *, 367 struct flowi6 *, 368 const struct sk_buff *, int); 369 370 struct fib6_entry_notifier_info { 371 struct fib_notifier_info info; /* must be first */ 372 struct fib6_info *rt; 373 }; 374 375 /* 376 * exported functions 377 */ 378 379 struct fib6_table *fib6_get_table(struct net *net, u32 id); 380 struct fib6_table *fib6_new_table(struct net *net, u32 id); 381 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 382 const struct sk_buff *skb, 383 int flags, pol_lookup_t lookup); 384 385 /* called with rcu lock held; can return error pointer 386 * caller needs to select path 387 */ 388 struct fib6_info *fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, 389 int flags); 390 391 /* called with rcu lock held; caller needs to select path */ 392 struct fib6_info *fib6_table_lookup(struct net *net, struct fib6_table *table, 393 int oif, struct flowi6 *fl6, int strict); 394 395 struct fib6_info *fib6_multipath_select(const struct net *net, 396 struct fib6_info *match, 397 struct flowi6 *fl6, int oif, 398 const struct sk_buff *skb, int strict); 399 400 struct fib6_node *fib6_node_lookup(struct fib6_node *root, 401 const struct in6_addr *daddr, 402 const struct in6_addr *saddr); 403 404 struct fib6_node *fib6_locate(struct fib6_node *root, 405 const struct in6_addr *daddr, int dst_len, 406 const struct in6_addr *saddr, int src_len, 407 bool exact_match); 408 409 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg), 410 void *arg); 411 412 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 413 struct nl_info *info, struct netlink_ext_ack *extack); 414 int fib6_del(struct fib6_info *rt, struct nl_info *info); 415 416 static inline struct net_device *fib6_info_nh_dev(const struct fib6_info *f6i) 417 { 418 return f6i->fib6_nh.nh_dev; 419 } 420 421 static inline 422 struct lwtunnel_state *fib6_info_nh_lwt(const struct fib6_info *f6i) 423 { 424 return f6i->fib6_nh.nh_lwtstate; 425 } 426 427 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info, 428 unsigned int flags); 429 430 void fib6_run_gc(unsigned long expires, struct net *net, bool force); 431 432 void fib6_gc_cleanup(void); 433 434 int fib6_init(void); 435 436 struct ipv6_route_iter { 437 struct seq_net_private p; 438 struct fib6_walker w; 439 loff_t skip; 440 struct fib6_table *tbl; 441 int sernum; 442 }; 443 444 extern const struct seq_operations ipv6_route_seq_ops; 445 446 int call_fib6_notifier(struct notifier_block *nb, struct net *net, 447 enum fib_event_type event_type, 448 struct fib_notifier_info *info); 449 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type, 450 struct fib_notifier_info *info); 451 452 int __net_init fib6_notifier_init(struct net *net); 453 void __net_exit fib6_notifier_exit(struct net *net); 454 455 unsigned int fib6_tables_seq_read(struct net *net); 456 int fib6_tables_dump(struct net *net, struct notifier_block *nb); 457 458 void fib6_update_sernum(struct net *net, struct fib6_info *rt); 459 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt); 460 461 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val); 462 static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric) 463 { 464 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric)); 465 } 466 467 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 468 int fib6_rules_init(void); 469 void fib6_rules_cleanup(void); 470 bool fib6_rule_default(const struct fib_rule *rule); 471 int fib6_rules_dump(struct net *net, struct notifier_block *nb); 472 unsigned int fib6_rules_seq_read(struct net *net); 473 474 static inline bool fib6_rules_early_flow_dissect(struct net *net, 475 struct sk_buff *skb, 476 struct flowi6 *fl6, 477 struct flow_keys *flkeys) 478 { 479 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 480 481 if (!net->ipv6.fib6_rules_require_fldissect) 482 return false; 483 484 skb_flow_dissect_flow_keys(skb, flkeys, flag); 485 fl6->fl6_sport = flkeys->ports.src; 486 fl6->fl6_dport = flkeys->ports.dst; 487 fl6->flowi6_proto = flkeys->basic.ip_proto; 488 489 return true; 490 } 491 #else 492 static inline int fib6_rules_init(void) 493 { 494 return 0; 495 } 496 static inline void fib6_rules_cleanup(void) 497 { 498 return ; 499 } 500 static inline bool fib6_rule_default(const struct fib_rule *rule) 501 { 502 return true; 503 } 504 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb) 505 { 506 return 0; 507 } 508 static inline unsigned int fib6_rules_seq_read(struct net *net) 509 { 510 return 0; 511 } 512 static inline bool fib6_rules_early_flow_dissect(struct net *net, 513 struct sk_buff *skb, 514 struct flowi6 *fl6, 515 struct flow_keys *flkeys) 516 { 517 return false; 518 } 519 #endif 520 #endif 521