1 /* 2 * INET An implementation of the TCP/IP protocol suite for the LINUX 3 * operating system. INET is implemented using the BSD Socket 4 * interface as the means of communication with the user level. 5 * 6 * Definitions for the Forwarding Information Base. 7 * 8 * Authors: A.N.Kuznetsov, <kuznet@ms2.inr.ac.ru> 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 16 #ifndef _NET_IP_FIB_H 17 #define _NET_IP_FIB_H 18 19 #include <net/flow.h> 20 #include <linux/seq_file.h> 21 #include <linux/rcupdate.h> 22 #include <net/fib_rules.h> 23 #include <net/inetpeer.h> 24 #include <linux/percpu.h> 25 #include <linux/notifier.h> 26 27 struct fib_config { 28 u8 fc_dst_len; 29 u8 fc_tos; 30 u8 fc_protocol; 31 u8 fc_scope; 32 u8 fc_type; 33 /* 3 bytes unused */ 34 u32 fc_table; 35 __be32 fc_dst; 36 __be32 fc_gw; 37 int fc_oif; 38 u32 fc_flags; 39 u32 fc_priority; 40 __be32 fc_prefsrc; 41 struct nlattr *fc_mx; 42 struct rtnexthop *fc_mp; 43 int fc_mx_len; 44 int fc_mp_len; 45 u32 fc_flow; 46 u32 fc_nlflags; 47 struct nl_info fc_nlinfo; 48 struct nlattr *fc_encap; 49 u16 fc_encap_type; 50 }; 51 52 struct fib_info; 53 struct rtable; 54 55 struct fib_nh_exception { 56 struct fib_nh_exception __rcu *fnhe_next; 57 int fnhe_genid; 58 __be32 fnhe_daddr; 59 u32 fnhe_pmtu; 60 __be32 fnhe_gw; 61 unsigned long fnhe_expires; 62 struct rtable __rcu *fnhe_rth_input; 63 struct rtable __rcu *fnhe_rth_output; 64 unsigned long fnhe_stamp; 65 struct rcu_head rcu; 66 }; 67 68 struct fnhe_hash_bucket { 69 struct fib_nh_exception __rcu *chain; 70 }; 71 72 #define FNHE_HASH_SHIFT 11 73 #define FNHE_HASH_SIZE (1 << FNHE_HASH_SHIFT) 74 #define FNHE_RECLAIM_DEPTH 5 75 76 struct fib_nh { 77 struct net_device *nh_dev; 78 struct hlist_node nh_hash; 79 struct fib_info *nh_parent; 80 unsigned int nh_flags; 81 unsigned char nh_scope; 82 #ifdef CONFIG_IP_ROUTE_MULTIPATH 83 int nh_weight; 84 atomic_t nh_upper_bound; 85 #endif 86 #ifdef CONFIG_IP_ROUTE_CLASSID 87 __u32 nh_tclassid; 88 #endif 89 int nh_oif; 90 __be32 nh_gw; 91 __be32 nh_saddr; 92 int nh_saddr_genid; 93 struct rtable __rcu * __percpu *nh_pcpu_rth_output; 94 struct rtable __rcu *nh_rth_input; 95 struct fnhe_hash_bucket __rcu *nh_exceptions; 96 struct lwtunnel_state *nh_lwtstate; 97 }; 98 99 /* 100 * This structure contains data shared by many of routes. 101 */ 102 103 struct fib_info { 104 struct hlist_node fib_hash; 105 struct hlist_node fib_lhash; 106 struct net *fib_net; 107 int fib_treeref; 108 atomic_t fib_clntref; 109 unsigned int fib_flags; 110 unsigned char fib_dead; 111 unsigned char fib_protocol; 112 unsigned char fib_scope; 113 unsigned char fib_type; 114 __be32 fib_prefsrc; 115 u32 fib_tb_id; 116 u32 fib_priority; 117 struct dst_metrics *fib_metrics; 118 #define fib_mtu fib_metrics->metrics[RTAX_MTU-1] 119 #define fib_window fib_metrics->metrics[RTAX_WINDOW-1] 120 #define fib_rtt fib_metrics->metrics[RTAX_RTT-1] 121 #define fib_advmss fib_metrics->metrics[RTAX_ADVMSS-1] 122 int fib_nhs; 123 #ifdef CONFIG_IP_ROUTE_MULTIPATH 124 int fib_weight; 125 #endif 126 unsigned int fib_offload_cnt; 127 struct rcu_head rcu; 128 struct fib_nh fib_nh[0]; 129 #define fib_dev fib_nh[0].nh_dev 130 }; 131 132 133 #ifdef CONFIG_IP_MULTIPLE_TABLES 134 struct fib_rule; 135 #endif 136 137 struct fib_table; 138 struct fib_result { 139 unsigned char prefixlen; 140 unsigned char nh_sel; 141 unsigned char type; 142 unsigned char scope; 143 u32 tclassid; 144 struct fib_info *fi; 145 struct fib_table *table; 146 struct hlist_head *fa_head; 147 }; 148 149 struct fib_result_nl { 150 __be32 fl_addr; /* To be looked up*/ 151 u32 fl_mark; 152 unsigned char fl_tos; 153 unsigned char fl_scope; 154 unsigned char tb_id_in; 155 156 unsigned char tb_id; /* Results */ 157 unsigned char prefixlen; 158 unsigned char nh_sel; 159 unsigned char type; 160 unsigned char scope; 161 int err; 162 }; 163 164 #ifdef CONFIG_IP_ROUTE_MULTIPATH 165 #define FIB_RES_NH(res) ((res).fi->fib_nh[(res).nh_sel]) 166 #else /* CONFIG_IP_ROUTE_MULTIPATH */ 167 #define FIB_RES_NH(res) ((res).fi->fib_nh[0]) 168 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 169 170 #ifdef CONFIG_IP_MULTIPLE_TABLES 171 #define FIB_TABLE_HASHSZ 256 172 #else 173 #define FIB_TABLE_HASHSZ 2 174 #endif 175 176 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh); 177 178 static inline void fib_info_offload_inc(struct fib_info *fi) 179 { 180 fi->fib_offload_cnt++; 181 fi->fib_flags |= RTNH_F_OFFLOAD; 182 } 183 184 static inline void fib_info_offload_dec(struct fib_info *fi) 185 { 186 if (--fi->fib_offload_cnt == 0) 187 fi->fib_flags &= ~RTNH_F_OFFLOAD; 188 } 189 190 #define FIB_RES_SADDR(net, res) \ 191 ((FIB_RES_NH(res).nh_saddr_genid == \ 192 atomic_read(&(net)->ipv4.dev_addr_genid)) ? \ 193 FIB_RES_NH(res).nh_saddr : \ 194 fib_info_update_nh_saddr((net), &FIB_RES_NH(res))) 195 #define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw) 196 #define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev) 197 #define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif) 198 199 #define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \ 200 FIB_RES_SADDR(net, res)) 201 202 struct fib_notifier_info { 203 struct net *net; 204 }; 205 206 struct fib_entry_notifier_info { 207 struct fib_notifier_info info; /* must be first */ 208 u32 dst; 209 int dst_len; 210 struct fib_info *fi; 211 u8 tos; 212 u8 type; 213 u32 tb_id; 214 }; 215 216 struct fib_rule_notifier_info { 217 struct fib_notifier_info info; /* must be first */ 218 struct fib_rule *rule; 219 }; 220 221 struct fib_nh_notifier_info { 222 struct fib_notifier_info info; /* must be first */ 223 struct fib_nh *fib_nh; 224 }; 225 226 enum fib_event_type { 227 FIB_EVENT_ENTRY_REPLACE, 228 FIB_EVENT_ENTRY_APPEND, 229 FIB_EVENT_ENTRY_ADD, 230 FIB_EVENT_ENTRY_DEL, 231 FIB_EVENT_RULE_ADD, 232 FIB_EVENT_RULE_DEL, 233 FIB_EVENT_NH_ADD, 234 FIB_EVENT_NH_DEL, 235 }; 236 237 int register_fib_notifier(struct notifier_block *nb, 238 void (*cb)(struct notifier_block *nb)); 239 int unregister_fib_notifier(struct notifier_block *nb); 240 int call_fib_notifier(struct notifier_block *nb, struct net *net, 241 enum fib_event_type event_type, 242 struct fib_notifier_info *info); 243 int call_fib_notifiers(struct net *net, enum fib_event_type event_type, 244 struct fib_notifier_info *info); 245 246 void fib_notify(struct net *net, struct notifier_block *nb); 247 #ifdef CONFIG_IP_MULTIPLE_TABLES 248 void fib_rules_notify(struct net *net, struct notifier_block *nb); 249 #else 250 static inline void fib_rules_notify(struct net *net, struct notifier_block *nb) 251 { 252 } 253 #endif 254 255 struct fib_table { 256 struct hlist_node tb_hlist; 257 u32 tb_id; 258 int tb_num_default; 259 struct rcu_head rcu; 260 unsigned long *tb_data; 261 unsigned long __data[0]; 262 }; 263 264 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 265 struct fib_result *res, int fib_flags); 266 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *); 267 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *); 268 int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 269 struct netlink_callback *cb); 270 int fib_table_flush(struct net *net, struct fib_table *table); 271 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb); 272 void fib_table_flush_external(struct fib_table *table); 273 void fib_free_table(struct fib_table *tb); 274 275 #ifndef CONFIG_IP_MULTIPLE_TABLES 276 277 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1)) 278 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1)) 279 280 static inline struct fib_table *fib_get_table(struct net *net, u32 id) 281 { 282 struct hlist_node *tb_hlist; 283 struct hlist_head *ptr; 284 285 ptr = id == RT_TABLE_LOCAL ? 286 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] : 287 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]; 288 289 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr)); 290 291 return hlist_entry(tb_hlist, struct fib_table, tb_hlist); 292 } 293 294 static inline struct fib_table *fib_new_table(struct net *net, u32 id) 295 { 296 return fib_get_table(net, id); 297 } 298 299 static inline int fib_lookup(struct net *net, const struct flowi4 *flp, 300 struct fib_result *res, unsigned int flags) 301 { 302 struct fib_table *tb; 303 int err = -ENETUNREACH; 304 305 rcu_read_lock(); 306 307 tb = fib_get_table(net, RT_TABLE_MAIN); 308 if (tb) 309 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF); 310 311 if (err == -EAGAIN) 312 err = -ENETUNREACH; 313 314 rcu_read_unlock(); 315 316 return err; 317 } 318 319 static inline bool fib4_rule_default(const struct fib_rule *rule) 320 { 321 return true; 322 } 323 324 #else /* CONFIG_IP_MULTIPLE_TABLES */ 325 int __net_init fib4_rules_init(struct net *net); 326 void __net_exit fib4_rules_exit(struct net *net); 327 328 struct fib_table *fib_new_table(struct net *net, u32 id); 329 struct fib_table *fib_get_table(struct net *net, u32 id); 330 331 int __fib_lookup(struct net *net, struct flowi4 *flp, 332 struct fib_result *res, unsigned int flags); 333 334 static inline int fib_lookup(struct net *net, struct flowi4 *flp, 335 struct fib_result *res, unsigned int flags) 336 { 337 struct fib_table *tb; 338 int err = -ENETUNREACH; 339 340 flags |= FIB_LOOKUP_NOREF; 341 if (net->ipv4.fib_has_custom_rules) 342 return __fib_lookup(net, flp, res, flags); 343 344 rcu_read_lock(); 345 346 res->tclassid = 0; 347 348 tb = rcu_dereference_rtnl(net->ipv4.fib_main); 349 if (tb) 350 err = fib_table_lookup(tb, flp, res, flags); 351 352 if (!err) 353 goto out; 354 355 tb = rcu_dereference_rtnl(net->ipv4.fib_default); 356 if (tb) 357 err = fib_table_lookup(tb, flp, res, flags); 358 359 out: 360 if (err == -EAGAIN) 361 err = -ENETUNREACH; 362 363 rcu_read_unlock(); 364 365 return err; 366 } 367 368 bool fib4_rule_default(const struct fib_rule *rule); 369 370 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 371 372 /* Exported by fib_frontend.c */ 373 extern const struct nla_policy rtm_ipv4_policy[]; 374 void ip_fib_init(void); 375 __be32 fib_compute_spec_dst(struct sk_buff *skb); 376 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 377 u8 tos, int oif, struct net_device *dev, 378 struct in_device *idev, u32 *itag); 379 #ifdef CONFIG_IP_ROUTE_CLASSID 380 static inline int fib_num_tclassid_users(struct net *net) 381 { 382 return net->ipv4.fib_num_tclassid_users; 383 } 384 #else 385 static inline int fib_num_tclassid_users(struct net *net) 386 { 387 return 0; 388 } 389 #endif 390 int fib_unmerge(struct net *net); 391 392 /* Exported by fib_semantics.c */ 393 int ip_fib_check_default(__be32 gw, struct net_device *dev); 394 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force); 395 int fib_sync_down_addr(struct net_device *dev, __be32 local); 396 int fib_sync_up(struct net_device *dev, unsigned int nh_flags); 397 398 #ifdef CONFIG_IP_ROUTE_MULTIPATH 399 int fib_multipath_hash(const struct fib_info *fi, const struct flowi4 *fl4, 400 const struct sk_buff *skb); 401 #endif 402 void fib_select_multipath(struct fib_result *res, int hash); 403 void fib_select_path(struct net *net, struct fib_result *res, 404 struct flowi4 *fl4, const struct sk_buff *skb); 405 406 /* Exported by fib_trie.c */ 407 void fib_trie_init(void); 408 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias); 409 410 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 411 { 412 #ifdef CONFIG_IP_ROUTE_CLASSID 413 #ifdef CONFIG_IP_MULTIPLE_TABLES 414 u32 rtag; 415 #endif 416 *itag = FIB_RES_NH(*res).nh_tclassid<<16; 417 #ifdef CONFIG_IP_MULTIPLE_TABLES 418 rtag = res->tclassid; 419 if (*itag == 0) 420 *itag = (rtag<<16); 421 *itag |= (rtag>>16); 422 #endif 423 #endif 424 } 425 426 void free_fib_info(struct fib_info *fi); 427 428 static inline void fib_info_hold(struct fib_info *fi) 429 { 430 atomic_inc(&fi->fib_clntref); 431 } 432 433 static inline void fib_info_put(struct fib_info *fi) 434 { 435 if (atomic_dec_and_test(&fi->fib_clntref)) 436 free_fib_info(fi); 437 } 438 439 #ifdef CONFIG_PROC_FS 440 int __net_init fib_proc_init(struct net *net); 441 void __net_exit fib_proc_exit(struct net *net); 442 #else 443 static inline int fib_proc_init(struct net *net) 444 { 445 return 0; 446 } 447 static inline void fib_proc_exit(struct net *net) 448 { 449 } 450 #endif 451 452 #endif /* _NET_FIB_H */ 453