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 42 struct fib6_config { 43 u32 fc_table; 44 u32 fc_metric; 45 int fc_dst_len; 46 int fc_src_len; 47 int fc_ifindex; 48 u32 fc_flags; 49 u32 fc_protocol; 50 u16 fc_type; /* only 8 bits are used */ 51 u16 fc_delete_all_nh : 1, 52 __unused : 15; 53 54 struct in6_addr fc_dst; 55 struct in6_addr fc_src; 56 struct in6_addr fc_prefsrc; 57 struct in6_addr fc_gateway; 58 59 unsigned long fc_expires; 60 struct nlattr *fc_mx; 61 int fc_mx_len; 62 int fc_mp_len; 63 struct nlattr *fc_mp; 64 65 struct nl_info fc_nlinfo; 66 struct nlattr *fc_encap; 67 u16 fc_encap_type; 68 }; 69 70 struct fib6_node { 71 struct fib6_node __rcu *parent; 72 struct fib6_node __rcu *left; 73 struct fib6_node __rcu *right; 74 #ifdef CONFIG_IPV6_SUBTREES 75 struct fib6_node __rcu *subtree; 76 #endif 77 struct rt6_info __rcu *leaf; 78 79 __u16 fn_bit; /* bit key */ 80 __u16 fn_flags; 81 int fn_sernum; 82 struct rt6_info __rcu *rr_ptr; 83 struct rcu_head rcu; 84 }; 85 86 struct fib6_gc_args { 87 int timeout; 88 int more; 89 }; 90 91 #ifndef CONFIG_IPV6_SUBTREES 92 #define FIB6_SUBTREE(fn) NULL 93 #else 94 #define FIB6_SUBTREE(fn) (rcu_dereference_protected((fn)->subtree, 1)) 95 #endif 96 97 struct mx6_config { 98 const u32 *mx; 99 DECLARE_BITMAP(mx_valid, RTAX_MAX); 100 }; 101 102 /* 103 * routing information 104 * 105 */ 106 107 struct rt6key { 108 struct in6_addr addr; 109 int plen; 110 }; 111 112 struct fib6_table; 113 114 struct rt6_exception_bucket { 115 struct hlist_head chain; 116 int depth; 117 }; 118 119 struct rt6_exception { 120 struct hlist_node hlist; 121 struct rt6_info *rt6i; 122 unsigned long stamp; 123 struct rcu_head rcu; 124 }; 125 126 #define FIB6_EXCEPTION_BUCKET_SIZE_SHIFT 10 127 #define FIB6_EXCEPTION_BUCKET_SIZE (1 << FIB6_EXCEPTION_BUCKET_SIZE_SHIFT) 128 #define FIB6_MAX_DEPTH 5 129 130 struct rt6_info { 131 struct dst_entry dst; 132 133 /* 134 * Tail elements of dst_entry (__refcnt etc.) 135 * and these elements (rarely used in hot path) are in 136 * the same cache line. 137 */ 138 struct fib6_table *rt6i_table; 139 struct fib6_node __rcu *rt6i_node; 140 141 struct in6_addr rt6i_gateway; 142 143 /* Multipath routes: 144 * siblings is a list of rt6_info that have the the same metric/weight, 145 * destination, but not the same gateway. nsiblings is just a cache 146 * to speed up lookup. 147 */ 148 struct list_head rt6i_siblings; 149 unsigned int rt6i_nsiblings; 150 151 atomic_t rt6i_ref; 152 153 unsigned int rt6i_nh_flags; 154 155 /* These are in a separate cache line. */ 156 struct rt6key rt6i_dst ____cacheline_aligned_in_smp; 157 u32 rt6i_flags; 158 struct rt6key rt6i_src; 159 struct rt6key rt6i_prefsrc; 160 161 struct list_head rt6i_uncached; 162 struct uncached_list *rt6i_uncached_list; 163 164 struct inet6_dev *rt6i_idev; 165 struct rt6_info * __percpu *rt6i_pcpu; 166 struct rt6_exception_bucket __rcu *rt6i_exception_bucket; 167 168 u32 rt6i_metric; 169 u32 rt6i_pmtu; 170 /* more non-fragment space at head required */ 171 unsigned short rt6i_nfheader_len; 172 u8 rt6i_protocol; 173 u8 exception_bucket_flushed:1, 174 unused:7; 175 }; 176 177 #define for_each_fib6_node_rt_rcu(fn) \ 178 for (rt = rcu_dereference((fn)->leaf); rt; \ 179 rt = rcu_dereference(rt->dst.rt6_next)) 180 181 #define for_each_fib6_walker_rt(w) \ 182 for (rt = (w)->leaf; rt; \ 183 rt = rcu_dereference_protected(rt->dst.rt6_next, 1)) 184 185 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst) 186 { 187 return ((struct rt6_info *)dst)->rt6i_idev; 188 } 189 190 static inline void rt6_clean_expires(struct rt6_info *rt) 191 { 192 rt->rt6i_flags &= ~RTF_EXPIRES; 193 rt->dst.expires = 0; 194 } 195 196 static inline void rt6_set_expires(struct rt6_info *rt, unsigned long expires) 197 { 198 rt->dst.expires = expires; 199 rt->rt6i_flags |= RTF_EXPIRES; 200 } 201 202 static inline void rt6_update_expires(struct rt6_info *rt0, int timeout) 203 { 204 struct rt6_info *rt; 205 206 for (rt = rt0; rt && !(rt->rt6i_flags & RTF_EXPIRES); 207 rt = (struct rt6_info *)rt->dst.from); 208 if (rt && rt != rt0) 209 rt0->dst.expires = rt->dst.expires; 210 211 dst_set_expires(&rt0->dst, timeout); 212 rt0->rt6i_flags |= RTF_EXPIRES; 213 } 214 215 /* Function to safely get fn->sernum for passed in rt 216 * and store result in passed in cookie. 217 * Return true if we can get cookie safely 218 * Return false if not 219 */ 220 static inline bool rt6_get_cookie_safe(const struct rt6_info *rt, 221 u32 *cookie) 222 { 223 struct fib6_node *fn; 224 bool status = false; 225 226 rcu_read_lock(); 227 fn = rcu_dereference(rt->rt6i_node); 228 229 if (fn) { 230 *cookie = fn->fn_sernum; 231 /* pairs with smp_wmb() in fib6_update_sernum_upto_root() */ 232 smp_rmb(); 233 status = true; 234 } 235 236 rcu_read_unlock(); 237 return status; 238 } 239 240 static inline u32 rt6_get_cookie(const struct rt6_info *rt) 241 { 242 u32 cookie = 0; 243 244 if (rt->rt6i_flags & RTF_PCPU || 245 (unlikely(!list_empty(&rt->rt6i_uncached)) && rt->dst.from)) 246 rt = (struct rt6_info *)(rt->dst.from); 247 248 rt6_get_cookie_safe(rt, &cookie); 249 250 return cookie; 251 } 252 253 static inline void ip6_rt_put(struct rt6_info *rt) 254 { 255 /* dst_release() accepts a NULL parameter. 256 * We rely on dst being first structure in struct rt6_info 257 */ 258 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0); 259 dst_release(&rt->dst); 260 } 261 262 void rt6_free_pcpu(struct rt6_info *non_pcpu_rt); 263 264 static inline void rt6_hold(struct rt6_info *rt) 265 { 266 atomic_inc(&rt->rt6i_ref); 267 } 268 269 static inline void rt6_release(struct rt6_info *rt) 270 { 271 if (atomic_dec_and_test(&rt->rt6i_ref)) { 272 rt6_free_pcpu(rt); 273 dst_dev_put(&rt->dst); 274 dst_release(&rt->dst); 275 } 276 } 277 278 enum fib6_walk_state { 279 #ifdef CONFIG_IPV6_SUBTREES 280 FWS_S, 281 #endif 282 FWS_L, 283 FWS_R, 284 FWS_C, 285 FWS_U 286 }; 287 288 struct fib6_walker { 289 struct list_head lh; 290 struct fib6_node *root, *node; 291 struct rt6_info *leaf; 292 enum fib6_walk_state state; 293 unsigned int skip; 294 unsigned int count; 295 int (*func)(struct fib6_walker *); 296 void *args; 297 }; 298 299 struct rt6_statistics { 300 __u32 fib_nodes; /* all fib6 nodes */ 301 __u32 fib_route_nodes; /* intermediate nodes */ 302 __u32 fib_rt_entries; /* rt entries in fib table */ 303 __u32 fib_rt_cache; /* cached rt entries in exception table */ 304 __u32 fib_discarded_routes; /* total number of routes delete */ 305 306 /* The following stats are not protected by any lock */ 307 atomic_t fib_rt_alloc; /* total number of routes alloced */ 308 atomic_t fib_rt_uncache; /* rt entries in uncached list */ 309 }; 310 311 #define RTN_TL_ROOT 0x0001 312 #define RTN_ROOT 0x0002 /* tree root node */ 313 #define RTN_RTINFO 0x0004 /* node with valid routing info */ 314 315 /* 316 * priority levels (or metrics) 317 * 318 */ 319 320 321 struct fib6_table { 322 struct hlist_node tb6_hlist; 323 u32 tb6_id; 324 spinlock_t tb6_lock; 325 struct fib6_node tb6_root; 326 struct inet_peer_base tb6_peers; 327 unsigned int flags; 328 unsigned int fib_seq; 329 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0) 330 }; 331 332 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC 333 #define RT6_TABLE_MAIN RT_TABLE_MAIN 334 #define RT6_TABLE_DFLT RT6_TABLE_MAIN 335 #define RT6_TABLE_INFO RT6_TABLE_MAIN 336 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN 337 338 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 339 #define FIB6_TABLE_MIN 1 340 #define FIB6_TABLE_MAX RT_TABLE_MAX 341 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL 342 #else 343 #define FIB6_TABLE_MIN RT_TABLE_MAIN 344 #define FIB6_TABLE_MAX FIB6_TABLE_MIN 345 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN 346 #endif 347 348 typedef struct rt6_info *(*pol_lookup_t)(struct net *, 349 struct fib6_table *, 350 struct flowi6 *, int); 351 352 struct fib6_entry_notifier_info { 353 struct fib_notifier_info info; /* must be first */ 354 struct rt6_info *rt; 355 }; 356 357 /* 358 * exported functions 359 */ 360 361 struct fib6_table *fib6_get_table(struct net *net, u32 id); 362 struct fib6_table *fib6_new_table(struct net *net, u32 id); 363 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 364 int flags, pol_lookup_t lookup); 365 366 struct fib6_node *fib6_lookup(struct fib6_node *root, 367 const struct in6_addr *daddr, 368 const struct in6_addr *saddr); 369 370 struct fib6_node *fib6_locate(struct fib6_node *root, 371 const struct in6_addr *daddr, int dst_len, 372 const struct in6_addr *saddr, int src_len, 373 bool exact_match); 374 375 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg), 376 void *arg); 377 378 int fib6_add(struct fib6_node *root, struct rt6_info *rt, 379 struct nl_info *info, struct mx6_config *mxc, 380 struct netlink_ext_ack *extack); 381 int fib6_del(struct rt6_info *rt, struct nl_info *info); 382 383 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info, 384 unsigned int flags); 385 386 void fib6_run_gc(unsigned long expires, struct net *net, bool force); 387 388 void fib6_gc_cleanup(void); 389 390 int fib6_init(void); 391 392 int ipv6_route_open(struct inode *inode, struct file *file); 393 394 int call_fib6_notifier(struct notifier_block *nb, struct net *net, 395 enum fib_event_type event_type, 396 struct fib_notifier_info *info); 397 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type, 398 struct fib_notifier_info *info); 399 400 int __net_init fib6_notifier_init(struct net *net); 401 void __net_exit fib6_notifier_exit(struct net *net); 402 403 unsigned int fib6_tables_seq_read(struct net *net); 404 int fib6_tables_dump(struct net *net, struct notifier_block *nb); 405 406 void fib6_update_sernum(struct rt6_info *rt); 407 408 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 409 int fib6_rules_init(void); 410 void fib6_rules_cleanup(void); 411 bool fib6_rule_default(const struct fib_rule *rule); 412 int fib6_rules_dump(struct net *net, struct notifier_block *nb); 413 unsigned int fib6_rules_seq_read(struct net *net); 414 #else 415 static inline int fib6_rules_init(void) 416 { 417 return 0; 418 } 419 static inline void fib6_rules_cleanup(void) 420 { 421 return ; 422 } 423 static inline bool fib6_rule_default(const struct fib_rule *rule) 424 { 425 return true; 426 } 427 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb) 428 { 429 return 0; 430 } 431 static inline unsigned int fib6_rules_seq_read(struct net *net) 432 { 433 return 0; 434 } 435 #endif 436 #endif 437