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 }; 174 175 struct rt6_info { 176 struct dst_entry dst; 177 struct fib6_info __rcu *from; 178 179 struct rt6key rt6i_dst; 180 struct rt6key rt6i_src; 181 struct in6_addr rt6i_gateway; 182 struct inet6_dev *rt6i_idev; 183 u32 rt6i_flags; 184 struct rt6key rt6i_prefsrc; 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(struct fib6_info *f6i); 277 278 static inline void fib6_info_hold(struct fib6_info *f6i) 279 { 280 atomic_inc(&f6i->fib6_ref); 281 } 282 283 static inline void fib6_info_release(struct fib6_info *f6i) 284 { 285 if (f6i && atomic_dec_and_test(&f6i->fib6_ref)) 286 fib6_info_destroy(f6i); 287 } 288 289 enum fib6_walk_state { 290 #ifdef CONFIG_IPV6_SUBTREES 291 FWS_S, 292 #endif 293 FWS_L, 294 FWS_R, 295 FWS_C, 296 FWS_U 297 }; 298 299 struct fib6_walker { 300 struct list_head lh; 301 struct fib6_node *root, *node; 302 struct fib6_info *leaf; 303 enum fib6_walk_state state; 304 unsigned int skip; 305 unsigned int count; 306 int (*func)(struct fib6_walker *); 307 void *args; 308 }; 309 310 struct rt6_statistics { 311 __u32 fib_nodes; /* all fib6 nodes */ 312 __u32 fib_route_nodes; /* intermediate nodes */ 313 __u32 fib_rt_entries; /* rt entries in fib table */ 314 __u32 fib_rt_cache; /* cached rt entries in exception table */ 315 __u32 fib_discarded_routes; /* total number of routes delete */ 316 317 /* The following stats are not protected by any lock */ 318 atomic_t fib_rt_alloc; /* total number of routes alloced */ 319 atomic_t fib_rt_uncache; /* rt entries in uncached list */ 320 }; 321 322 #define RTN_TL_ROOT 0x0001 323 #define RTN_ROOT 0x0002 /* tree root node */ 324 #define RTN_RTINFO 0x0004 /* node with valid routing info */ 325 326 /* 327 * priority levels (or metrics) 328 * 329 */ 330 331 332 struct fib6_table { 333 struct hlist_node tb6_hlist; 334 u32 tb6_id; 335 spinlock_t tb6_lock; 336 struct fib6_node tb6_root; 337 struct inet_peer_base tb6_peers; 338 unsigned int flags; 339 unsigned int fib_seq; 340 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0) 341 }; 342 343 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC 344 #define RT6_TABLE_MAIN RT_TABLE_MAIN 345 #define RT6_TABLE_DFLT RT6_TABLE_MAIN 346 #define RT6_TABLE_INFO RT6_TABLE_MAIN 347 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN 348 349 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 350 #define FIB6_TABLE_MIN 1 351 #define FIB6_TABLE_MAX RT_TABLE_MAX 352 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL 353 #else 354 #define FIB6_TABLE_MIN RT_TABLE_MAIN 355 #define FIB6_TABLE_MAX FIB6_TABLE_MIN 356 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN 357 #endif 358 359 typedef struct rt6_info *(*pol_lookup_t)(struct net *, 360 struct fib6_table *, 361 struct flowi6 *, 362 const struct sk_buff *, int); 363 364 struct fib6_entry_notifier_info { 365 struct fib_notifier_info info; /* must be first */ 366 struct fib6_info *rt; 367 }; 368 369 /* 370 * exported functions 371 */ 372 373 struct fib6_table *fib6_get_table(struct net *net, u32 id); 374 struct fib6_table *fib6_new_table(struct net *net, u32 id); 375 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 376 const struct sk_buff *skb, 377 int flags, pol_lookup_t lookup); 378 379 /* called with rcu lock held; can return error pointer 380 * caller needs to select path 381 */ 382 struct fib6_info *fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, 383 int flags); 384 385 /* called with rcu lock held; caller needs to select path */ 386 struct fib6_info *fib6_table_lookup(struct net *net, struct fib6_table *table, 387 int oif, struct flowi6 *fl6, int strict); 388 389 struct fib6_info *fib6_multipath_select(const struct net *net, 390 struct fib6_info *match, 391 struct flowi6 *fl6, int oif, 392 const struct sk_buff *skb, int strict); 393 394 struct fib6_node *fib6_node_lookup(struct fib6_node *root, 395 const struct in6_addr *daddr, 396 const struct in6_addr *saddr); 397 398 struct fib6_node *fib6_locate(struct fib6_node *root, 399 const struct in6_addr *daddr, int dst_len, 400 const struct in6_addr *saddr, int src_len, 401 bool exact_match); 402 403 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg), 404 void *arg); 405 406 int fib6_add(struct fib6_node *root, struct fib6_info *rt, 407 struct nl_info *info, struct netlink_ext_ack *extack); 408 int fib6_del(struct fib6_info *rt, struct nl_info *info); 409 410 static inline struct net_device *fib6_info_nh_dev(const struct fib6_info *f6i) 411 { 412 return f6i->fib6_nh.nh_dev; 413 } 414 415 static inline 416 struct lwtunnel_state *fib6_info_nh_lwt(const struct fib6_info *f6i) 417 { 418 return f6i->fib6_nh.nh_lwtstate; 419 } 420 421 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info, 422 unsigned int flags); 423 424 void fib6_run_gc(unsigned long expires, struct net *net, bool force); 425 426 void fib6_gc_cleanup(void); 427 428 int fib6_init(void); 429 430 struct ipv6_route_iter { 431 struct seq_net_private p; 432 struct fib6_walker w; 433 loff_t skip; 434 struct fib6_table *tbl; 435 int sernum; 436 }; 437 438 extern const struct seq_operations ipv6_route_seq_ops; 439 440 int call_fib6_notifier(struct notifier_block *nb, struct net *net, 441 enum fib_event_type event_type, 442 struct fib_notifier_info *info); 443 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type, 444 struct fib_notifier_info *info); 445 446 int __net_init fib6_notifier_init(struct net *net); 447 void __net_exit fib6_notifier_exit(struct net *net); 448 449 unsigned int fib6_tables_seq_read(struct net *net); 450 int fib6_tables_dump(struct net *net, struct notifier_block *nb); 451 452 void fib6_update_sernum(struct net *net, struct fib6_info *rt); 453 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt); 454 455 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val); 456 static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric) 457 { 458 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric)); 459 } 460 461 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 462 int fib6_rules_init(void); 463 void fib6_rules_cleanup(void); 464 bool fib6_rule_default(const struct fib_rule *rule); 465 int fib6_rules_dump(struct net *net, struct notifier_block *nb); 466 unsigned int fib6_rules_seq_read(struct net *net); 467 468 static inline bool fib6_rules_early_flow_dissect(struct net *net, 469 struct sk_buff *skb, 470 struct flowi6 *fl6, 471 struct flow_keys *flkeys) 472 { 473 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 474 475 if (!net->ipv6.fib6_rules_require_fldissect) 476 return false; 477 478 skb_flow_dissect_flow_keys(skb, flkeys, flag); 479 fl6->fl6_sport = flkeys->ports.src; 480 fl6->fl6_dport = flkeys->ports.dst; 481 fl6->flowi6_proto = flkeys->basic.ip_proto; 482 483 return true; 484 } 485 #else 486 static inline int fib6_rules_init(void) 487 { 488 return 0; 489 } 490 static inline void fib6_rules_cleanup(void) 491 { 492 return ; 493 } 494 static inline bool fib6_rule_default(const struct fib_rule *rule) 495 { 496 return true; 497 } 498 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb) 499 { 500 return 0; 501 } 502 static inline unsigned int fib6_rules_seq_read(struct net *net) 503 { 504 return 0; 505 } 506 static inline bool fib6_rules_early_flow_dissect(struct net *net, 507 struct sk_buff *skb, 508 struct flowi6 *fl6, 509 struct flow_keys *flkeys) 510 { 511 return false; 512 } 513 #endif 514 #endif 515