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 #include <linux/refcount.h> 27 28 struct fib_config { 29 u8 fc_dst_len; 30 u8 fc_tos; 31 u8 fc_protocol; 32 u8 fc_scope; 33 u8 fc_type; 34 /* 3 bytes unused */ 35 u32 fc_table; 36 __be32 fc_dst; 37 __be32 fc_gw; 38 int fc_oif; 39 u32 fc_flags; 40 u32 fc_priority; 41 __be32 fc_prefsrc; 42 struct nlattr *fc_mx; 43 struct rtnexthop *fc_mp; 44 int fc_mx_len; 45 int fc_mp_len; 46 u32 fc_flow; 47 u32 fc_nlflags; 48 struct nl_info fc_nlinfo; 49 struct nlattr *fc_encap; 50 u16 fc_encap_type; 51 }; 52 53 struct fib_info; 54 struct rtable; 55 56 struct fib_nh_exception { 57 struct fib_nh_exception __rcu *fnhe_next; 58 int fnhe_genid; 59 __be32 fnhe_daddr; 60 u32 fnhe_pmtu; 61 __be32 fnhe_gw; 62 unsigned long fnhe_expires; 63 struct rtable __rcu *fnhe_rth_input; 64 struct rtable __rcu *fnhe_rth_output; 65 unsigned long fnhe_stamp; 66 struct rcu_head rcu; 67 }; 68 69 struct fnhe_hash_bucket { 70 struct fib_nh_exception __rcu *chain; 71 }; 72 73 #define FNHE_HASH_SHIFT 11 74 #define FNHE_HASH_SIZE (1 << FNHE_HASH_SHIFT) 75 #define FNHE_RECLAIM_DEPTH 5 76 77 struct fib_nh { 78 struct net_device *nh_dev; 79 struct hlist_node nh_hash; 80 struct fib_info *nh_parent; 81 unsigned int nh_flags; 82 unsigned char nh_scope; 83 #ifdef CONFIG_IP_ROUTE_MULTIPATH 84 int nh_weight; 85 atomic_t nh_upper_bound; 86 #endif 87 #ifdef CONFIG_IP_ROUTE_CLASSID 88 __u32 nh_tclassid; 89 #endif 90 int nh_oif; 91 __be32 nh_gw; 92 __be32 nh_saddr; 93 int nh_saddr_genid; 94 struct rtable __rcu * __percpu *nh_pcpu_rth_output; 95 struct rtable __rcu *nh_rth_input; 96 struct fnhe_hash_bucket __rcu *nh_exceptions; 97 struct lwtunnel_state *nh_lwtstate; 98 }; 99 100 /* 101 * This structure contains data shared by many of routes. 102 */ 103 104 struct fib_info { 105 struct hlist_node fib_hash; 106 struct hlist_node fib_lhash; 107 struct net *fib_net; 108 int fib_treeref; 109 refcount_t fib_clntref; 110 unsigned int fib_flags; 111 unsigned char fib_dead; 112 unsigned char fib_protocol; 113 unsigned char fib_scope; 114 unsigned char fib_type; 115 __be32 fib_prefsrc; 116 u32 fib_tb_id; 117 u32 fib_priority; 118 struct dst_metrics *fib_metrics; 119 #define fib_mtu fib_metrics->metrics[RTAX_MTU-1] 120 #define fib_window fib_metrics->metrics[RTAX_WINDOW-1] 121 #define fib_rtt fib_metrics->metrics[RTAX_RTT-1] 122 #define fib_advmss fib_metrics->metrics[RTAX_ADVMSS-1] 123 int fib_nhs; 124 #ifdef CONFIG_IP_ROUTE_MULTIPATH 125 int fib_weight; 126 #endif 127 unsigned int fib_offload_cnt; 128 struct rcu_head rcu; 129 struct fib_nh fib_nh[0]; 130 #define fib_dev fib_nh[0].nh_dev 131 }; 132 133 134 #ifdef CONFIG_IP_MULTIPLE_TABLES 135 struct fib_rule; 136 #endif 137 138 struct fib_table; 139 struct fib_result { 140 __be32 prefix; 141 unsigned char prefixlen; 142 unsigned char nh_sel; 143 unsigned char type; 144 unsigned char scope; 145 u32 tclassid; 146 struct fib_info *fi; 147 struct fib_table *table; 148 struct hlist_head *fa_head; 149 }; 150 151 struct fib_result_nl { 152 __be32 fl_addr; /* To be looked up*/ 153 u32 fl_mark; 154 unsigned char fl_tos; 155 unsigned char fl_scope; 156 unsigned char tb_id_in; 157 158 unsigned char tb_id; /* Results */ 159 unsigned char prefixlen; 160 unsigned char nh_sel; 161 unsigned char type; 162 unsigned char scope; 163 int err; 164 }; 165 166 #ifdef CONFIG_IP_ROUTE_MULTIPATH 167 #define FIB_RES_NH(res) ((res).fi->fib_nh[(res).nh_sel]) 168 #else /* CONFIG_IP_ROUTE_MULTIPATH */ 169 #define FIB_RES_NH(res) ((res).fi->fib_nh[0]) 170 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 171 172 #ifdef CONFIG_IP_MULTIPLE_TABLES 173 #define FIB_TABLE_HASHSZ 256 174 #else 175 #define FIB_TABLE_HASHSZ 2 176 #endif 177 178 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh); 179 180 static inline void fib_info_offload_inc(struct fib_info *fi) 181 { 182 fi->fib_offload_cnt++; 183 fi->fib_flags |= RTNH_F_OFFLOAD; 184 } 185 186 static inline void fib_info_offload_dec(struct fib_info *fi) 187 { 188 if (--fi->fib_offload_cnt == 0) 189 fi->fib_flags &= ~RTNH_F_OFFLOAD; 190 } 191 192 #define FIB_RES_SADDR(net, res) \ 193 ((FIB_RES_NH(res).nh_saddr_genid == \ 194 atomic_read(&(net)->ipv4.dev_addr_genid)) ? \ 195 FIB_RES_NH(res).nh_saddr : \ 196 fib_info_update_nh_saddr((net), &FIB_RES_NH(res))) 197 #define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw) 198 #define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev) 199 #define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif) 200 201 #define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \ 202 FIB_RES_SADDR(net, res)) 203 204 struct fib_notifier_info { 205 struct net *net; 206 }; 207 208 struct fib_entry_notifier_info { 209 struct fib_notifier_info info; /* must be first */ 210 u32 dst; 211 int dst_len; 212 struct fib_info *fi; 213 u8 tos; 214 u8 type; 215 u32 tb_id; 216 }; 217 218 struct fib_rule_notifier_info { 219 struct fib_notifier_info info; /* must be first */ 220 struct fib_rule *rule; 221 }; 222 223 struct fib_nh_notifier_info { 224 struct fib_notifier_info info; /* must be first */ 225 struct fib_nh *fib_nh; 226 }; 227 228 enum fib_event_type { 229 FIB_EVENT_ENTRY_REPLACE, 230 FIB_EVENT_ENTRY_APPEND, 231 FIB_EVENT_ENTRY_ADD, 232 FIB_EVENT_ENTRY_DEL, 233 FIB_EVENT_RULE_ADD, 234 FIB_EVENT_RULE_DEL, 235 FIB_EVENT_NH_ADD, 236 FIB_EVENT_NH_DEL, 237 }; 238 239 int register_fib_notifier(struct notifier_block *nb, 240 void (*cb)(struct notifier_block *nb)); 241 int unregister_fib_notifier(struct notifier_block *nb); 242 int call_fib_notifier(struct notifier_block *nb, struct net *net, 243 enum fib_event_type event_type, 244 struct fib_notifier_info *info); 245 int call_fib_notifiers(struct net *net, enum fib_event_type event_type, 246 struct fib_notifier_info *info); 247 248 void fib_notify(struct net *net, struct notifier_block *nb); 249 #ifdef CONFIG_IP_MULTIPLE_TABLES 250 void fib_rules_notify(struct net *net, struct notifier_block *nb); 251 #else 252 static inline void fib_rules_notify(struct net *net, struct notifier_block *nb) 253 { 254 } 255 #endif 256 257 struct fib_table { 258 struct hlist_node tb_hlist; 259 u32 tb_id; 260 int tb_num_default; 261 struct rcu_head rcu; 262 unsigned long *tb_data; 263 unsigned long __data[0]; 264 }; 265 266 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 267 struct fib_result *res, int fib_flags); 268 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *, 269 struct netlink_ext_ack *extack); 270 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *, 271 struct netlink_ext_ack *extack); 272 int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 273 struct netlink_callback *cb); 274 int fib_table_flush(struct net *net, struct fib_table *table); 275 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb); 276 void fib_table_flush_external(struct fib_table *table); 277 void fib_free_table(struct fib_table *tb); 278 279 #ifndef CONFIG_IP_MULTIPLE_TABLES 280 281 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1)) 282 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1)) 283 284 static inline struct fib_table *fib_get_table(struct net *net, u32 id) 285 { 286 struct hlist_node *tb_hlist; 287 struct hlist_head *ptr; 288 289 ptr = id == RT_TABLE_LOCAL ? 290 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] : 291 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]; 292 293 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr)); 294 295 return hlist_entry(tb_hlist, struct fib_table, tb_hlist); 296 } 297 298 static inline struct fib_table *fib_new_table(struct net *net, u32 id) 299 { 300 return fib_get_table(net, id); 301 } 302 303 static inline int fib_lookup(struct net *net, const struct flowi4 *flp, 304 struct fib_result *res, unsigned int flags) 305 { 306 struct fib_table *tb; 307 int err = -ENETUNREACH; 308 309 rcu_read_lock(); 310 311 tb = fib_get_table(net, RT_TABLE_MAIN); 312 if (tb) 313 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF); 314 315 if (err == -EAGAIN) 316 err = -ENETUNREACH; 317 318 rcu_read_unlock(); 319 320 return err; 321 } 322 323 static inline bool fib4_rule_default(const struct fib_rule *rule) 324 { 325 return true; 326 } 327 328 #else /* CONFIG_IP_MULTIPLE_TABLES */ 329 int __net_init fib4_rules_init(struct net *net); 330 void __net_exit fib4_rules_exit(struct net *net); 331 332 struct fib_table *fib_new_table(struct net *net, u32 id); 333 struct fib_table *fib_get_table(struct net *net, u32 id); 334 335 int __fib_lookup(struct net *net, struct flowi4 *flp, 336 struct fib_result *res, unsigned int flags); 337 338 static inline int fib_lookup(struct net *net, struct flowi4 *flp, 339 struct fib_result *res, unsigned int flags) 340 { 341 struct fib_table *tb; 342 int err = -ENETUNREACH; 343 344 flags |= FIB_LOOKUP_NOREF; 345 if (net->ipv4.fib_has_custom_rules) 346 return __fib_lookup(net, flp, res, flags); 347 348 rcu_read_lock(); 349 350 res->tclassid = 0; 351 352 tb = rcu_dereference_rtnl(net->ipv4.fib_main); 353 if (tb) 354 err = fib_table_lookup(tb, flp, res, flags); 355 356 if (!err) 357 goto out; 358 359 tb = rcu_dereference_rtnl(net->ipv4.fib_default); 360 if (tb) 361 err = fib_table_lookup(tb, flp, res, flags); 362 363 out: 364 if (err == -EAGAIN) 365 err = -ENETUNREACH; 366 367 rcu_read_unlock(); 368 369 return err; 370 } 371 372 bool fib4_rule_default(const struct fib_rule *rule); 373 374 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 375 376 /* Exported by fib_frontend.c */ 377 extern const struct nla_policy rtm_ipv4_policy[]; 378 void ip_fib_init(void); 379 __be32 fib_compute_spec_dst(struct sk_buff *skb); 380 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 381 u8 tos, int oif, struct net_device *dev, 382 struct in_device *idev, u32 *itag); 383 #ifdef CONFIG_IP_ROUTE_CLASSID 384 static inline int fib_num_tclassid_users(struct net *net) 385 { 386 return net->ipv4.fib_num_tclassid_users; 387 } 388 #else 389 static inline int fib_num_tclassid_users(struct net *net) 390 { 391 return 0; 392 } 393 #endif 394 int fib_unmerge(struct net *net); 395 396 /* Exported by fib_semantics.c */ 397 int ip_fib_check_default(__be32 gw, struct net_device *dev); 398 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force); 399 int fib_sync_down_addr(struct net_device *dev, __be32 local); 400 int fib_sync_up(struct net_device *dev, unsigned int nh_flags); 401 402 #ifdef CONFIG_IP_ROUTE_MULTIPATH 403 int fib_multipath_hash(const struct fib_info *fi, const struct flowi4 *fl4, 404 const struct sk_buff *skb); 405 #endif 406 void fib_select_multipath(struct fib_result *res, int hash); 407 void fib_select_path(struct net *net, struct fib_result *res, 408 struct flowi4 *fl4, const struct sk_buff *skb); 409 410 /* Exported by fib_trie.c */ 411 void fib_trie_init(void); 412 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias); 413 414 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 415 { 416 #ifdef CONFIG_IP_ROUTE_CLASSID 417 #ifdef CONFIG_IP_MULTIPLE_TABLES 418 u32 rtag; 419 #endif 420 *itag = FIB_RES_NH(*res).nh_tclassid<<16; 421 #ifdef CONFIG_IP_MULTIPLE_TABLES 422 rtag = res->tclassid; 423 if (*itag == 0) 424 *itag = (rtag<<16); 425 *itag |= (rtag>>16); 426 #endif 427 #endif 428 } 429 430 void free_fib_info(struct fib_info *fi); 431 432 static inline void fib_info_hold(struct fib_info *fi) 433 { 434 refcount_inc(&fi->fib_clntref); 435 } 436 437 static inline void fib_info_put(struct fib_info *fi) 438 { 439 if (refcount_dec_and_test(&fi->fib_clntref)) 440 free_fib_info(fi); 441 } 442 443 #ifdef CONFIG_PROC_FS 444 int __net_init fib_proc_init(struct net *net); 445 void __net_exit fib_proc_exit(struct net *net); 446 #else 447 static inline int fib_proc_init(struct net *net) 448 { 449 return 0; 450 } 451 static inline void fib_proc_exit(struct net *net) 452 { 453 } 454 #endif 455 456 #endif /* _NET_FIB_H */ 457