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 struct rt6_info; 33 34 struct fib6_config { 35 u32 fc_table; 36 u32 fc_metric; 37 int fc_dst_len; 38 int fc_src_len; 39 int fc_ifindex; 40 u32 fc_flags; 41 u32 fc_protocol; 42 u16 fc_type; /* only 8 bits are used */ 43 u16 fc_delete_all_nh : 1, 44 __unused : 15; 45 46 struct in6_addr fc_dst; 47 struct in6_addr fc_src; 48 struct in6_addr fc_prefsrc; 49 struct in6_addr fc_gateway; 50 51 unsigned long fc_expires; 52 struct nlattr *fc_mx; 53 int fc_mx_len; 54 int fc_mp_len; 55 struct nlattr *fc_mp; 56 57 struct nl_info fc_nlinfo; 58 struct nlattr *fc_encap; 59 u16 fc_encap_type; 60 }; 61 62 struct fib6_node { 63 struct fib6_node *parent; 64 struct fib6_node *left; 65 struct fib6_node *right; 66 #ifdef CONFIG_IPV6_SUBTREES 67 struct fib6_node *subtree; 68 #endif 69 struct rt6_info *leaf; 70 71 __u16 fn_bit; /* bit key */ 72 __u16 fn_flags; 73 int fn_sernum; 74 struct rt6_info *rr_ptr; 75 struct rcu_head rcu; 76 }; 77 78 #ifndef CONFIG_IPV6_SUBTREES 79 #define FIB6_SUBTREE(fn) NULL 80 #else 81 #define FIB6_SUBTREE(fn) ((fn)->subtree) 82 #endif 83 84 struct mx6_config { 85 const u32 *mx; 86 DECLARE_BITMAP(mx_valid, RTAX_MAX); 87 }; 88 89 /* 90 * routing information 91 * 92 */ 93 94 struct rt6key { 95 struct in6_addr addr; 96 int plen; 97 }; 98 99 struct fib6_table; 100 101 struct rt6_info { 102 struct dst_entry dst; 103 104 /* 105 * Tail elements of dst_entry (__refcnt etc.) 106 * and these elements (rarely used in hot path) are in 107 * the same cache line. 108 */ 109 struct fib6_table *rt6i_table; 110 struct fib6_node __rcu *rt6i_node; 111 112 struct in6_addr rt6i_gateway; 113 114 /* Multipath routes: 115 * siblings is a list of rt6_info that have the the same metric/weight, 116 * destination, but not the same gateway. nsiblings is just a cache 117 * to speed up lookup. 118 */ 119 struct list_head rt6i_siblings; 120 unsigned int rt6i_nsiblings; 121 122 atomic_t rt6i_ref; 123 124 unsigned int rt6i_nh_flags; 125 126 /* These are in a separate cache line. */ 127 struct rt6key rt6i_dst ____cacheline_aligned_in_smp; 128 u32 rt6i_flags; 129 struct rt6key rt6i_src; 130 struct rt6key rt6i_prefsrc; 131 132 struct list_head rt6i_uncached; 133 struct uncached_list *rt6i_uncached_list; 134 135 struct inet6_dev *rt6i_idev; 136 struct rt6_info * __percpu *rt6i_pcpu; 137 138 u32 rt6i_metric; 139 u32 rt6i_pmtu; 140 /* more non-fragment space at head required */ 141 unsigned short rt6i_nfheader_len; 142 u8 rt6i_protocol; 143 }; 144 145 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst) 146 { 147 return ((struct rt6_info *)dst)->rt6i_idev; 148 } 149 150 static inline void rt6_clean_expires(struct rt6_info *rt) 151 { 152 rt->rt6i_flags &= ~RTF_EXPIRES; 153 rt->dst.expires = 0; 154 } 155 156 static inline void rt6_set_expires(struct rt6_info *rt, unsigned long expires) 157 { 158 rt->dst.expires = expires; 159 rt->rt6i_flags |= RTF_EXPIRES; 160 } 161 162 static inline void rt6_update_expires(struct rt6_info *rt0, int timeout) 163 { 164 struct rt6_info *rt; 165 166 for (rt = rt0; rt && !(rt->rt6i_flags & RTF_EXPIRES); 167 rt = (struct rt6_info *)rt->dst.from); 168 if (rt && rt != rt0) 169 rt0->dst.expires = rt->dst.expires; 170 171 dst_set_expires(&rt0->dst, timeout); 172 rt0->rt6i_flags |= RTF_EXPIRES; 173 } 174 175 /* Function to safely get fn->sernum for passed in rt 176 * and store result in passed in cookie. 177 * Return true if we can get cookie safely 178 * Return false if not 179 */ 180 static inline bool rt6_get_cookie_safe(const struct rt6_info *rt, 181 u32 *cookie) 182 { 183 struct fib6_node *fn; 184 bool status = false; 185 186 rcu_read_lock(); 187 fn = rcu_dereference(rt->rt6i_node); 188 189 if (fn) { 190 *cookie = fn->fn_sernum; 191 status = true; 192 } 193 194 rcu_read_unlock(); 195 return status; 196 } 197 198 static inline u32 rt6_get_cookie(const struct rt6_info *rt) 199 { 200 u32 cookie = 0; 201 202 if (rt->rt6i_flags & RTF_PCPU || 203 (unlikely(!list_empty(&rt->rt6i_uncached)) && rt->dst.from)) 204 rt = (struct rt6_info *)(rt->dst.from); 205 206 rt6_get_cookie_safe(rt, &cookie); 207 208 return cookie; 209 } 210 211 static inline void ip6_rt_put(struct rt6_info *rt) 212 { 213 /* dst_release() accepts a NULL parameter. 214 * We rely on dst being first structure in struct rt6_info 215 */ 216 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0); 217 dst_release(&rt->dst); 218 } 219 220 void rt6_free_pcpu(struct rt6_info *non_pcpu_rt); 221 222 static inline void rt6_hold(struct rt6_info *rt) 223 { 224 atomic_inc(&rt->rt6i_ref); 225 } 226 227 static inline void rt6_release(struct rt6_info *rt) 228 { 229 if (atomic_dec_and_test(&rt->rt6i_ref)) { 230 rt6_free_pcpu(rt); 231 dst_dev_put(&rt->dst); 232 dst_release(&rt->dst); 233 } 234 } 235 236 enum fib6_walk_state { 237 #ifdef CONFIG_IPV6_SUBTREES 238 FWS_S, 239 #endif 240 FWS_L, 241 FWS_R, 242 FWS_C, 243 FWS_U 244 }; 245 246 struct fib6_walker { 247 struct list_head lh; 248 struct fib6_node *root, *node; 249 struct rt6_info *leaf; 250 enum fib6_walk_state state; 251 bool prune; 252 unsigned int skip; 253 unsigned int count; 254 int (*func)(struct fib6_walker *); 255 void *args; 256 }; 257 258 struct rt6_statistics { 259 __u32 fib_nodes; 260 __u32 fib_route_nodes; 261 __u32 fib_rt_alloc; /* permanent routes */ 262 __u32 fib_rt_entries; /* rt entries in table */ 263 __u32 fib_rt_cache; /* cache routes */ 264 __u32 fib_discarded_routes; 265 }; 266 267 #define RTN_TL_ROOT 0x0001 268 #define RTN_ROOT 0x0002 /* tree root node */ 269 #define RTN_RTINFO 0x0004 /* node with valid routing info */ 270 271 /* 272 * priority levels (or metrics) 273 * 274 */ 275 276 277 struct fib6_table { 278 struct hlist_node tb6_hlist; 279 u32 tb6_id; 280 rwlock_t tb6_lock; 281 struct fib6_node tb6_root; 282 struct inet_peer_base tb6_peers; 283 unsigned int flags; 284 unsigned int fib_seq; 285 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0) 286 }; 287 288 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC 289 #define RT6_TABLE_MAIN RT_TABLE_MAIN 290 #define RT6_TABLE_DFLT RT6_TABLE_MAIN 291 #define RT6_TABLE_INFO RT6_TABLE_MAIN 292 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN 293 294 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 295 #define FIB6_TABLE_MIN 1 296 #define FIB6_TABLE_MAX RT_TABLE_MAX 297 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL 298 #else 299 #define FIB6_TABLE_MIN RT_TABLE_MAIN 300 #define FIB6_TABLE_MAX FIB6_TABLE_MIN 301 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN 302 #endif 303 304 typedef struct rt6_info *(*pol_lookup_t)(struct net *, 305 struct fib6_table *, 306 struct flowi6 *, int); 307 308 struct fib6_entry_notifier_info { 309 struct fib_notifier_info info; /* must be first */ 310 struct rt6_info *rt; 311 }; 312 313 /* 314 * exported functions 315 */ 316 317 struct fib6_table *fib6_get_table(struct net *net, u32 id); 318 struct fib6_table *fib6_new_table(struct net *net, u32 id); 319 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6, 320 int flags, pol_lookup_t lookup); 321 322 struct fib6_node *fib6_lookup(struct fib6_node *root, 323 const struct in6_addr *daddr, 324 const struct in6_addr *saddr); 325 326 struct fib6_node *fib6_locate(struct fib6_node *root, 327 const struct in6_addr *daddr, int dst_len, 328 const struct in6_addr *saddr, int src_len); 329 330 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg), 331 void *arg); 332 333 int fib6_add(struct fib6_node *root, struct rt6_info *rt, 334 struct nl_info *info, struct mx6_config *mxc, 335 struct netlink_ext_ack *extack); 336 int fib6_del(struct rt6_info *rt, struct nl_info *info); 337 338 void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info, 339 unsigned int flags); 340 341 void fib6_run_gc(unsigned long expires, struct net *net, bool force); 342 343 void fib6_gc_cleanup(void); 344 345 int fib6_init(void); 346 347 int ipv6_route_open(struct inode *inode, struct file *file); 348 349 int call_fib6_notifier(struct notifier_block *nb, struct net *net, 350 enum fib_event_type event_type, 351 struct fib_notifier_info *info); 352 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type, 353 struct fib_notifier_info *info); 354 355 int __net_init fib6_notifier_init(struct net *net); 356 void __net_exit fib6_notifier_exit(struct net *net); 357 358 unsigned int fib6_tables_seq_read(struct net *net); 359 int fib6_tables_dump(struct net *net, struct notifier_block *nb); 360 361 #ifdef CONFIG_IPV6_MULTIPLE_TABLES 362 int fib6_rules_init(void); 363 void fib6_rules_cleanup(void); 364 bool fib6_rule_default(const struct fib_rule *rule); 365 int fib6_rules_dump(struct net *net, struct notifier_block *nb); 366 unsigned int fib6_rules_seq_read(struct net *net); 367 #else 368 static inline int fib6_rules_init(void) 369 { 370 return 0; 371 } 372 static inline void fib6_rules_cleanup(void) 373 { 374 return ; 375 } 376 static inline bool fib6_rule_default(const struct fib_rule *rule) 377 { 378 return true; 379 } 380 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb) 381 { 382 return 0; 383 } 384 static inline unsigned int fib6_rules_seq_read(struct net *net) 385 { 386 return 0; 387 } 388 #endif 389 #endif 390