1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 */ 8 9 #ifndef _IP6_FIB_H 10 #define _IP6_FIB_H 11 12 #include <linux/ipv6_route.h> 13 #include <linux/rtnetlink.h> 14 #include <linux/spinlock.h> 15 #include <linux/notifier.h> 16 #include <net/dst.h> 17 #include <net/flow.h> 18 #include <net/ip_fib.h> 19 #include <net/netlink.h> 20 #include <net/inetpeer.h> 21 #include <net/fib_notifier.h> 22 23 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 24 #define FIB6_TABLE_HASHSZ 256 25 #else 26 #define FIB6_TABLE_HASHSZ 1 27 #endif 28 29 #define RT6_DEBUG 2 30 31 #if RT6_DEBUG >= 3 32 #define RT6_TRACE(x...) pr_debug(x) 33 #else 34 #define RT6_TRACE(x...) do { ; } while (0) 35 #endif 36 37 struct rt6_info; 38 struct fib6_info; 39 40 struct fib6_config { 41 u32 fc_table; 42 u32 fc_metric; 43 int fc_dst_len; 44 int fc_src_len; 45 int fc_ifindex; 46 u32 fc_flags; 47 u32 fc_protocol; 48 u16 fc_type; /* only 8 bits are used */ 49 u16 fc_delete_all_nh : 1, 50 fc_ignore_dev_down:1, 51 __unused : 14; 52 53 struct in6_addr fc_dst; 54 struct in6_addr fc_src; 55 struct in6_addr fc_prefsrc; 56 struct in6_addr fc_gateway; 57 58 unsigned long fc_expires; 59 struct nlattr *fc_mx; 60 int fc_mx_len; 61 int fc_mp_len; 62 struct nlattr *fc_mp; 63 64 struct nl_info fc_nlinfo; 65 struct nlattr *fc_encap; 66 u16 fc_encap_type; 67 }; 68 69 struct fib6_node { 70 struct fib6_node __rcu *parent; 71 struct fib6_node __rcu *left; 72 struct fib6_node __rcu *right; 73 #ifdef CONFIG_IPV6_SUBTREES 74 struct fib6_node __rcu *subtree; 75 #endif 76 struct fib6_info __rcu *leaf; 77 78 __u16 fn_bit; /* bit key */ 79 __u16 fn_flags; 80 int fn_sernum; 81 struct fib6_info __rcu *rr_ptr; 82 struct rcu_head rcu; 83 }; 84 85 struct fib6_gc_args { 86 int timeout; 87 int more; 88 }; 89 90 #ifndef CONFIG_IPV6_SUBTREES 91 #define FIB6_SUBTREE(fn) NULL 92 #else 93 #define FIB6_SUBTREE(fn) (rcu_dereference_protected((fn)->subtree, 1)) 94 #endif 95 96 /* 97 * routing information 98 * 99 */ 100 101 struct rt6key { 102 struct in6_addr addr; 103 int plen; 104 }; 105 106 struct fib6_table; 107 108 struct rt6_exception_bucket { 109 struct hlist_head chain; 110 int depth; 111 }; 112 113 struct rt6_exception { 114 struct hlist_node hlist; 115 struct rt6_info *rt6i; 116 unsigned long stamp; 117 struct rcu_head rcu; 118 }; 119 120 #define FIB6_EXCEPTION_BUCKET_SIZE_SHIFT 10 121 #define FIB6_EXCEPTION_BUCKET_SIZE (1 << FIB6_EXCEPTION_BUCKET_SIZE_SHIFT) 122 #define FIB6_MAX_DEPTH 5 123 124 struct fib6_nh { 125 struct fib_nh_common nh_common; 126 127 #ifdef CONFIG_IPV6_ROUTER_PREF 128 unsigned long last_probe; 129 #endif 130 }; 131 132 struct fib6_info { 133 struct fib6_table *fib6_table; 134 struct fib6_info __rcu *fib6_next; 135 struct fib6_node __rcu *fib6_node; 136 137 /* Multipath routes: 138 * siblings is a list of fib6_info that have the the same metric/weight, 139 * destination, but not the same gateway. nsiblings is just a cache 140 * to speed up lookup. 141 */ 142 struct list_head fib6_siblings; 143 unsigned int fib6_nsiblings; 144 145 refcount_t fib6_ref; 146 unsigned long expires; 147 struct dst_metrics *fib6_metrics; 148 #define fib6_pmtu fib6_metrics->metrics[RTAX_MTU-1] 149 150 struct rt6key fib6_dst; 151 u32 fib6_flags; 152 struct rt6key fib6_src; 153 struct rt6key fib6_prefsrc; 154 155 struct rt6_info * __percpu *rt6i_pcpu; 156 struct rt6_exception_bucket __rcu *rt6i_exception_bucket; 157 158 u32 fib6_metric; 159 u8 fib6_protocol; 160 u8 fib6_type; 161 u8 exception_bucket_flushed:1, 162 should_flush:1, 163 dst_nocount:1, 164 dst_nopolicy:1, 165 dst_host:1, 166 fib6_destroying:1, 167 unused:2; 168 169 struct fib6_nh fib6_nh; 170 struct rcu_head rcu; 171 }; 172 173 struct rt6_info { 174 struct dst_entry dst; 175 struct fib6_info __rcu *from; 176 177 struct rt6key rt6i_dst; 178 struct rt6key rt6i_src; 179 struct in6_addr rt6i_gateway; 180 struct inet6_dev *rt6i_idev; 181 u32 rt6i_flags; 182 183 struct list_head rt6i_uncached; 184 struct uncached_list *rt6i_uncached_list; 185 186 /* more non-fragment space at head required */ 187 unsigned short rt6i_nfheader_len; 188 }; 189 190 struct fib6_result { 191 struct fib6_nh *nh; 192 struct fib6_info *f6i; 193 u32 fib6_flags; 194 u8 fib6_type; 195 struct rt6_info *rt6; 196 }; 197 198 #define for_each_fib6_node_rt_rcu(fn) \ 199 for (rt = rcu_dereference((fn)->leaf); rt; \ 200 rt = rcu_dereference(rt->fib6_next)) 201 202 #define for_each_fib6_walker_rt(w) \ 203 for (rt = (w)->leaf; rt; \ 204 rt = rcu_dereference_protected(rt->fib6_next, 1)) 205 206 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst) 207 { 208 return ((struct rt6_info *)dst)->rt6i_idev; 209 } 210 211 static inline void fib6_clean_expires(struct fib6_info *f6i) 212 { 213 f6i->fib6_flags &= ~RTF_EXPIRES; 214 f6i->expires = 0; 215 } 216 217 static inline void fib6_set_expires(struct fib6_info *f6i, 218 unsigned long expires) 219 { 220 f6i->expires = expires; 221 f6i->fib6_flags |= RTF_EXPIRES; 222 } 223 224 static inline bool fib6_check_expired(const struct fib6_info *f6i) 225 { 226 if (f6i->fib6_flags & RTF_EXPIRES) 227 return time_after(jiffies, f6i->expires); 228 return false; 229 } 230 231 /* Function to safely get fn->sernum for passed in rt 232 * and store result in passed in cookie. 233 * Return true if we can get cookie safely 234 * Return false if not 235 */ 236 static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i, 237 u32 *cookie) 238 { 239 struct fib6_node *fn; 240 bool status = false; 241 242 fn = rcu_dereference(f6i->fib6_node); 243 244 if (fn) { 245 *cookie = fn->fn_sernum; 246 /* pairs with smp_wmb() in fib6_update_sernum_upto_root() */ 247 smp_rmb(); 248 status = true; 249 } 250 251 return status; 252 } 253 254 static inline u32 rt6_get_cookie(const struct rt6_info *rt) 255 { 256 struct fib6_info *from; 257 u32 cookie = 0; 258 259 rcu_read_lock(); 260 261 from = rcu_dereference(rt->from); 262 if (from && (rt->rt6i_flags & RTF_PCPU || 263 unlikely(!list_empty(&rt->rt6i_uncached)))) 264 fib6_get_cookie_safe(from, &cookie); 265 266 rcu_read_unlock(); 267 268 return cookie; 269 } 270 271 static inline void ip6_rt_put(struct rt6_info *rt) 272 { 273 /* dst_release() accepts a NULL parameter. 274 * We rely on dst being first structure in struct rt6_info 275 */ 276 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0); 277 dst_release(&rt->dst); 278 } 279 280 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags); 281 void fib6_info_destroy_rcu(struct rcu_head *head); 282 283 static inline void fib6_info_hold(struct fib6_info *f6i) 284 { 285 refcount_inc(&f6i->fib6_ref); 286 } 287 288 static inline bool fib6_info_hold_safe(struct fib6_info *f6i) 289 { 290 return refcount_inc_not_zero(&f6i->fib6_ref); 291 } 292 293 static inline void fib6_info_release(struct fib6_info *f6i) 294 { 295 if (f6i && refcount_dec_and_test(&f6i->fib6_ref)) 296 call_rcu(&f6i->rcu, fib6_info_destroy_rcu); 297 } 298 299 enum fib6_walk_state { 300 #ifdef CONFIG_IPV6_SUBTREES 301 FWS_S, 302 #endif 303 FWS_L, 304 FWS_R, 305 FWS_C, 306 FWS_U 307 }; 308 309 struct fib6_walker { 310 struct list_head lh; 311 struct fib6_node *root, *node; 312 struct fib6_info *leaf; 313 enum fib6_walk_state state; 314 unsigned int skip; 315 unsigned int count; 316 int (*func)(struct fib6_walker *); 317 void *args; 318 }; 319 320 struct rt6_statistics { 321 __u32 fib_nodes; /* all fib6 nodes */ 322 __u32 fib_route_nodes; /* intermediate nodes */ 323 __u32 fib_rt_entries; /* rt entries in fib table */ 324 __u32 fib_rt_cache; /* cached rt entries in exception table */ 325 __u32 fib_discarded_routes; /* total number of routes delete */ 326 327 /* The following stats are not protected by any lock */ 328 atomic_t fib_rt_alloc; /* total number of routes alloced */ 329 atomic_t fib_rt_uncache; /* rt entries in uncached list */ 330 }; 331 332 #define RTN_TL_ROOT 0x0001 333 #define RTN_ROOT 0x0002 /* tree root node */ 334 #define RTN_RTINFO 0x0004 /* node with valid routing info */ 335 336 /* 337 * priority levels (or metrics) 338 * 339 */ 340 341 342 struct fib6_table { 343 struct hlist_node tb6_hlist; 344 u32 tb6_id; 345 spinlock_t tb6_lock; 346 struct fib6_node tb6_root; 347 struct inet_peer_base tb6_peers; 348 unsigned int flags; 349 unsigned int fib_seq; 350 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0) 351 }; 352 353 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC 354 #define RT6_TABLE_MAIN RT_TABLE_MAIN 355 #define RT6_TABLE_DFLT RT6_TABLE_MAIN 356 #define RT6_TABLE_INFO RT6_TABLE_MAIN 357 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN 358 359 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 360 #define FIB6_TABLE_MIN 1 361 #define FIB6_TABLE_MAX RT_TABLE_MAX 362 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL 363 #else 364 #define FIB6_TABLE_MIN RT_TABLE_MAIN 365 #define FIB6_TABLE_MAX FIB6_TABLE_MIN 366 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN 367 #endif 368 369 typedef struct rt6_info *(*pol_lookup_t)(struct net *, 370 struct fib6_table *, 371 struct flowi6 *, 372 const struct sk_buff *, int); 373 374 struct fib6_entry_notifier_info { 375 struct fib_notifier_info info; /* must be first */ 376 struct fib6_info *rt; 377 }; 378 379 /* 380 * exported functions 381 */ 382 383 struct fib6_table *fib6_get_table(struct net *net, u32 id); 384 struct fib6_table *fib6_new_table(struct net *net, u32 id); 385 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 386 const struct sk_buff *skb, 387 int flags, pol_lookup_t lookup); 388 389 /* called with rcu lock held; can return error pointer 390 * caller needs to select path 391 */ 392 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6, 393 struct fib6_result *res, int flags); 394 395 /* called with rcu lock held; caller needs to select path */ 396 int fib6_table_lookup(struct net *net, struct fib6_table *table, 397 int oif, struct flowi6 *fl6, struct fib6_result *res, 398 int strict); 399 400 void fib6_select_path(const struct net *net, struct fib6_result *res, 401 struct flowi6 *fl6, int oif, bool have_oif_match, 402 const struct sk_buff *skb, int strict); 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.fib_nh_dev; 444 } 445 446 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh, 447 struct fib6_config *cfg, gfp_t gfp_flags, 448 struct netlink_ext_ack *extack); 449 void fib6_nh_release(struct fib6_nh *fib6_nh); 450 451 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info, 452 unsigned int flags); 453 454 void fib6_run_gc(unsigned long expires, struct net *net, bool force); 455 456 void fib6_gc_cleanup(void); 457 458 int fib6_init(void); 459 460 struct ipv6_route_iter { 461 struct seq_net_private p; 462 struct fib6_walker w; 463 loff_t skip; 464 struct fib6_table *tbl; 465 int sernum; 466 }; 467 468 extern const struct seq_operations ipv6_route_seq_ops; 469 470 int call_fib6_notifier(struct notifier_block *nb, struct net *net, 471 enum fib_event_type event_type, 472 struct fib_notifier_info *info); 473 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type, 474 struct fib_notifier_info *info); 475 476 int __net_init fib6_notifier_init(struct net *net); 477 void __net_exit fib6_notifier_exit(struct net *net); 478 479 unsigned int fib6_tables_seq_read(struct net *net); 480 int fib6_tables_dump(struct net *net, struct notifier_block *nb); 481 482 void fib6_update_sernum(struct net *net, struct fib6_info *rt); 483 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt); 484 485 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val); 486 static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric) 487 { 488 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric)); 489 } 490 491 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 492 int fib6_rules_init(void); 493 void fib6_rules_cleanup(void); 494 bool fib6_rule_default(const struct fib_rule *rule); 495 int fib6_rules_dump(struct net *net, struct notifier_block *nb); 496 unsigned int fib6_rules_seq_read(struct net *net); 497 498 static inline bool fib6_rules_early_flow_dissect(struct net *net, 499 struct sk_buff *skb, 500 struct flowi6 *fl6, 501 struct flow_keys *flkeys) 502 { 503 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 504 505 if (!net->ipv6.fib6_rules_require_fldissect) 506 return false; 507 508 skb_flow_dissect_flow_keys(skb, flkeys, flag); 509 fl6->fl6_sport = flkeys->ports.src; 510 fl6->fl6_dport = flkeys->ports.dst; 511 fl6->flowi6_proto = flkeys->basic.ip_proto; 512 513 return true; 514 } 515 #else 516 static inline int fib6_rules_init(void) 517 { 518 return 0; 519 } 520 static inline void fib6_rules_cleanup(void) 521 { 522 return ; 523 } 524 static inline bool fib6_rule_default(const struct fib_rule *rule) 525 { 526 return true; 527 } 528 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb) 529 { 530 return 0; 531 } 532 static inline unsigned int fib6_rules_seq_read(struct net *net) 533 { 534 return 0; 535 } 536 static inline bool fib6_rules_early_flow_dissect(struct net *net, 537 struct sk_buff *skb, 538 struct flowi6 *fl6, 539 struct flow_keys *flkeys) 540 { 541 return false; 542 } 543 #endif 544 #endif 545