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 *parent; 72 struct fib6_node *left; 73 struct fib6_node *right; 74 #ifdef CONFIG_IPV6_SUBTREES 75 struct fib6_node *subtree; 76 #endif 77 struct rt6_info *leaf; 78 79 __u16 fn_bit; /* bit key */ 80 __u16 fn_flags; 81 int fn_sernum; 82 struct rt6_info *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) ((fn)->subtree) 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 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst) 178 { 179 return ((struct rt6_info *)dst)->rt6i_idev; 180 } 181 182 static inline void rt6_clean_expires(struct rt6_info *rt) 183 { 184 rt->rt6i_flags &= ~RTF_EXPIRES; 185 rt->dst.expires = 0; 186 } 187 188 static inline void rt6_set_expires(struct rt6_info *rt, unsigned long expires) 189 { 190 rt->dst.expires = expires; 191 rt->rt6i_flags |= RTF_EXPIRES; 192 } 193 194 static inline void rt6_update_expires(struct rt6_info *rt0, int timeout) 195 { 196 struct rt6_info *rt; 197 198 for (rt = rt0; rt && !(rt->rt6i_flags & RTF_EXPIRES); 199 rt = (struct rt6_info *)rt->dst.from); 200 if (rt && rt != rt0) 201 rt0->dst.expires = rt->dst.expires; 202 203 dst_set_expires(&rt0->dst, timeout); 204 rt0->rt6i_flags |= RTF_EXPIRES; 205 } 206 207 /* Function to safely get fn->sernum for passed in rt 208 * and store result in passed in cookie. 209 * Return true if we can get cookie safely 210 * Return false if not 211 */ 212 static inline bool rt6_get_cookie_safe(const struct rt6_info *rt, 213 u32 *cookie) 214 { 215 struct fib6_node *fn; 216 bool status = false; 217 218 rcu_read_lock(); 219 fn = rcu_dereference(rt->rt6i_node); 220 221 if (fn) { 222 *cookie = fn->fn_sernum; 223 status = true; 224 } 225 226 rcu_read_unlock(); 227 return status; 228 } 229 230 static inline u32 rt6_get_cookie(const struct rt6_info *rt) 231 { 232 u32 cookie = 0; 233 234 if (rt->rt6i_flags & RTF_PCPU || 235 (unlikely(!list_empty(&rt->rt6i_uncached)) && rt->dst.from)) 236 rt = (struct rt6_info *)(rt->dst.from); 237 238 rt6_get_cookie_safe(rt, &cookie); 239 240 return cookie; 241 } 242 243 static inline void ip6_rt_put(struct rt6_info *rt) 244 { 245 /* dst_release() accepts a NULL parameter. 246 * We rely on dst being first structure in struct rt6_info 247 */ 248 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0); 249 dst_release(&rt->dst); 250 } 251 252 void rt6_free_pcpu(struct rt6_info *non_pcpu_rt); 253 254 static inline void rt6_hold(struct rt6_info *rt) 255 { 256 atomic_inc(&rt->rt6i_ref); 257 } 258 259 static inline void rt6_release(struct rt6_info *rt) 260 { 261 if (atomic_dec_and_test(&rt->rt6i_ref)) { 262 rt6_free_pcpu(rt); 263 dst_dev_put(&rt->dst); 264 dst_release(&rt->dst); 265 } 266 } 267 268 enum fib6_walk_state { 269 #ifdef CONFIG_IPV6_SUBTREES 270 FWS_S, 271 #endif 272 FWS_L, 273 FWS_R, 274 FWS_C, 275 FWS_U 276 }; 277 278 struct fib6_walker { 279 struct list_head lh; 280 struct fib6_node *root, *node; 281 struct rt6_info *leaf; 282 enum fib6_walk_state state; 283 bool prune; 284 unsigned int skip; 285 unsigned int count; 286 int (*func)(struct fib6_walker *); 287 void *args; 288 }; 289 290 struct rt6_statistics { 291 __u32 fib_nodes; 292 __u32 fib_route_nodes; 293 __u32 fib_rt_alloc; /* permanent routes */ 294 __u32 fib_rt_entries; /* rt entries in table */ 295 __u32 fib_rt_cache; /* cache routes */ 296 __u32 fib_discarded_routes; 297 }; 298 299 #define RTN_TL_ROOT 0x0001 300 #define RTN_ROOT 0x0002 /* tree root node */ 301 #define RTN_RTINFO 0x0004 /* node with valid routing info */ 302 303 /* 304 * priority levels (or metrics) 305 * 306 */ 307 308 309 struct fib6_table { 310 struct hlist_node tb6_hlist; 311 u32 tb6_id; 312 rwlock_t tb6_lock; 313 struct fib6_node tb6_root; 314 struct inet_peer_base tb6_peers; 315 unsigned int flags; 316 unsigned int fib_seq; 317 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0) 318 }; 319 320 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC 321 #define RT6_TABLE_MAIN RT_TABLE_MAIN 322 #define RT6_TABLE_DFLT RT6_TABLE_MAIN 323 #define RT6_TABLE_INFO RT6_TABLE_MAIN 324 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN 325 326 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 327 #define FIB6_TABLE_MIN 1 328 #define FIB6_TABLE_MAX RT_TABLE_MAX 329 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL 330 #else 331 #define FIB6_TABLE_MIN RT_TABLE_MAIN 332 #define FIB6_TABLE_MAX FIB6_TABLE_MIN 333 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN 334 #endif 335 336 typedef struct rt6_info *(*pol_lookup_t)(struct net *, 337 struct fib6_table *, 338 struct flowi6 *, int); 339 340 struct fib6_entry_notifier_info { 341 struct fib_notifier_info info; /* must be first */ 342 struct rt6_info *rt; 343 }; 344 345 /* 346 * exported functions 347 */ 348 349 struct fib6_table *fib6_get_table(struct net *net, u32 id); 350 struct fib6_table *fib6_new_table(struct net *net, u32 id); 351 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 352 int flags, pol_lookup_t lookup); 353 354 struct fib6_node *fib6_lookup(struct fib6_node *root, 355 const struct in6_addr *daddr, 356 const struct in6_addr *saddr); 357 358 struct fib6_node *fib6_locate(struct fib6_node *root, 359 const struct in6_addr *daddr, int dst_len, 360 const struct in6_addr *saddr, int src_len); 361 362 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg), 363 void *arg); 364 365 int fib6_add(struct fib6_node *root, struct rt6_info *rt, 366 struct nl_info *info, struct mx6_config *mxc, 367 struct netlink_ext_ack *extack); 368 int fib6_del(struct rt6_info *rt, struct nl_info *info); 369 370 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info, 371 unsigned int flags); 372 373 void fib6_run_gc(unsigned long expires, struct net *net, bool force); 374 375 void fib6_gc_cleanup(void); 376 377 int fib6_init(void); 378 379 int ipv6_route_open(struct inode *inode, struct file *file); 380 381 int call_fib6_notifier(struct notifier_block *nb, struct net *net, 382 enum fib_event_type event_type, 383 struct fib_notifier_info *info); 384 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type, 385 struct fib_notifier_info *info); 386 387 int __net_init fib6_notifier_init(struct net *net); 388 void __net_exit fib6_notifier_exit(struct net *net); 389 390 unsigned int fib6_tables_seq_read(struct net *net); 391 int fib6_tables_dump(struct net *net, struct notifier_block *nb); 392 393 void fib6_update_sernum(struct rt6_info *rt); 394 395 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 396 int fib6_rules_init(void); 397 void fib6_rules_cleanup(void); 398 bool fib6_rule_default(const struct fib_rule *rule); 399 int fib6_rules_dump(struct net *net, struct notifier_block *nb); 400 unsigned int fib6_rules_seq_read(struct net *net); 401 #else 402 static inline int fib6_rules_init(void) 403 { 404 return 0; 405 } 406 static inline void fib6_rules_cleanup(void) 407 { 408 return ; 409 } 410 static inline bool fib6_rule_default(const struct fib_rule *rule) 411 { 412 return true; 413 } 414 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb) 415 { 416 return 0; 417 } 418 static inline unsigned int fib6_rules_seq_read(struct net *net) 419 { 420 return 0; 421 } 422 #endif 423 #endif 424