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 __be32 prefix; 140 unsigned char prefixlen; 141 unsigned char nh_sel; 142 unsigned char type; 143 unsigned char scope; 144 u32 tclassid; 145 struct fib_info *fi; 146 struct fib_table *table; 147 struct hlist_head *fa_head; 148 }; 149 150 struct fib_result_nl { 151 __be32 fl_addr; /* To be looked up*/ 152 u32 fl_mark; 153 unsigned char fl_tos; 154 unsigned char fl_scope; 155 unsigned char tb_id_in; 156 157 unsigned char tb_id; /* Results */ 158 unsigned char prefixlen; 159 unsigned char nh_sel; 160 unsigned char type; 161 unsigned char scope; 162 int err; 163 }; 164 165 #ifdef CONFIG_IP_ROUTE_MULTIPATH 166 #define FIB_RES_NH(res) ((res).fi->fib_nh[(res).nh_sel]) 167 #else /* CONFIG_IP_ROUTE_MULTIPATH */ 168 #define FIB_RES_NH(res) ((res).fi->fib_nh[0]) 169 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 170 171 #ifdef CONFIG_IP_MULTIPLE_TABLES 172 #define FIB_TABLE_HASHSZ 256 173 #else 174 #define FIB_TABLE_HASHSZ 2 175 #endif 176 177 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh); 178 179 static inline void fib_info_offload_inc(struct fib_info *fi) 180 { 181 fi->fib_offload_cnt++; 182 fi->fib_flags |= RTNH_F_OFFLOAD; 183 } 184 185 static inline void fib_info_offload_dec(struct fib_info *fi) 186 { 187 if (--fi->fib_offload_cnt == 0) 188 fi->fib_flags &= ~RTNH_F_OFFLOAD; 189 } 190 191 #define FIB_RES_SADDR(net, res) \ 192 ((FIB_RES_NH(res).nh_saddr_genid == \ 193 atomic_read(&(net)->ipv4.dev_addr_genid)) ? \ 194 FIB_RES_NH(res).nh_saddr : \ 195 fib_info_update_nh_saddr((net), &FIB_RES_NH(res))) 196 #define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw) 197 #define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev) 198 #define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif) 199 200 #define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \ 201 FIB_RES_SADDR(net, res)) 202 203 struct fib_notifier_info { 204 struct net *net; 205 }; 206 207 struct fib_entry_notifier_info { 208 struct fib_notifier_info info; /* must be first */ 209 u32 dst; 210 int dst_len; 211 struct fib_info *fi; 212 u8 tos; 213 u8 type; 214 u32 tb_id; 215 }; 216 217 struct fib_rule_notifier_info { 218 struct fib_notifier_info info; /* must be first */ 219 struct fib_rule *rule; 220 }; 221 222 struct fib_nh_notifier_info { 223 struct fib_notifier_info info; /* must be first */ 224 struct fib_nh *fib_nh; 225 }; 226 227 enum fib_event_type { 228 FIB_EVENT_ENTRY_REPLACE, 229 FIB_EVENT_ENTRY_APPEND, 230 FIB_EVENT_ENTRY_ADD, 231 FIB_EVENT_ENTRY_DEL, 232 FIB_EVENT_RULE_ADD, 233 FIB_EVENT_RULE_DEL, 234 FIB_EVENT_NH_ADD, 235 FIB_EVENT_NH_DEL, 236 }; 237 238 int register_fib_notifier(struct notifier_block *nb, 239 void (*cb)(struct notifier_block *nb)); 240 int unregister_fib_notifier(struct notifier_block *nb); 241 int call_fib_notifier(struct notifier_block *nb, struct net *net, 242 enum fib_event_type event_type, 243 struct fib_notifier_info *info); 244 int call_fib_notifiers(struct net *net, enum fib_event_type event_type, 245 struct fib_notifier_info *info); 246 247 void fib_notify(struct net *net, struct notifier_block *nb); 248 #ifdef CONFIG_IP_MULTIPLE_TABLES 249 void fib_rules_notify(struct net *net, struct notifier_block *nb); 250 #else 251 static inline void fib_rules_notify(struct net *net, struct notifier_block *nb) 252 { 253 } 254 #endif 255 256 struct fib_table { 257 struct hlist_node tb_hlist; 258 u32 tb_id; 259 int tb_num_default; 260 struct rcu_head rcu; 261 unsigned long *tb_data; 262 unsigned long __data[0]; 263 }; 264 265 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 266 struct fib_result *res, int fib_flags); 267 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *, 268 struct netlink_ext_ack *extack); 269 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *, 270 struct netlink_ext_ack *extack); 271 int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 272 struct netlink_callback *cb); 273 int fib_table_flush(struct net *net, struct fib_table *table); 274 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb); 275 void fib_table_flush_external(struct fib_table *table); 276 void fib_free_table(struct fib_table *tb); 277 278 #ifndef CONFIG_IP_MULTIPLE_TABLES 279 280 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1)) 281 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1)) 282 283 static inline struct fib_table *fib_get_table(struct net *net, u32 id) 284 { 285 struct hlist_node *tb_hlist; 286 struct hlist_head *ptr; 287 288 ptr = id == RT_TABLE_LOCAL ? 289 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] : 290 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]; 291 292 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr)); 293 294 return hlist_entry(tb_hlist, struct fib_table, tb_hlist); 295 } 296 297 static inline struct fib_table *fib_new_table(struct net *net, u32 id) 298 { 299 return fib_get_table(net, id); 300 } 301 302 static inline int fib_lookup(struct net *net, const struct flowi4 *flp, 303 struct fib_result *res, unsigned int flags) 304 { 305 struct fib_table *tb; 306 int err = -ENETUNREACH; 307 308 rcu_read_lock(); 309 310 tb = fib_get_table(net, RT_TABLE_MAIN); 311 if (tb) 312 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF); 313 314 if (err == -EAGAIN) 315 err = -ENETUNREACH; 316 317 rcu_read_unlock(); 318 319 return err; 320 } 321 322 static inline bool fib4_rule_default(const struct fib_rule *rule) 323 { 324 return true; 325 } 326 327 #else /* CONFIG_IP_MULTIPLE_TABLES */ 328 int __net_init fib4_rules_init(struct net *net); 329 void __net_exit fib4_rules_exit(struct net *net); 330 331 struct fib_table *fib_new_table(struct net *net, u32 id); 332 struct fib_table *fib_get_table(struct net *net, u32 id); 333 334 int __fib_lookup(struct net *net, struct flowi4 *flp, 335 struct fib_result *res, unsigned int flags); 336 337 static inline int fib_lookup(struct net *net, struct flowi4 *flp, 338 struct fib_result *res, unsigned int flags) 339 { 340 struct fib_table *tb; 341 int err = -ENETUNREACH; 342 343 flags |= FIB_LOOKUP_NOREF; 344 if (net->ipv4.fib_has_custom_rules) 345 return __fib_lookup(net, flp, res, flags); 346 347 rcu_read_lock(); 348 349 res->tclassid = 0; 350 351 tb = rcu_dereference_rtnl(net->ipv4.fib_main); 352 if (tb) 353 err = fib_table_lookup(tb, flp, res, flags); 354 355 if (!err) 356 goto out; 357 358 tb = rcu_dereference_rtnl(net->ipv4.fib_default); 359 if (tb) 360 err = fib_table_lookup(tb, flp, res, flags); 361 362 out: 363 if (err == -EAGAIN) 364 err = -ENETUNREACH; 365 366 rcu_read_unlock(); 367 368 return err; 369 } 370 371 bool fib4_rule_default(const struct fib_rule *rule); 372 373 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 374 375 /* Exported by fib_frontend.c */ 376 extern const struct nla_policy rtm_ipv4_policy[]; 377 void ip_fib_init(void); 378 __be32 fib_compute_spec_dst(struct sk_buff *skb); 379 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 380 u8 tos, int oif, struct net_device *dev, 381 struct in_device *idev, u32 *itag); 382 #ifdef CONFIG_IP_ROUTE_CLASSID 383 static inline int fib_num_tclassid_users(struct net *net) 384 { 385 return net->ipv4.fib_num_tclassid_users; 386 } 387 #else 388 static inline int fib_num_tclassid_users(struct net *net) 389 { 390 return 0; 391 } 392 #endif 393 int fib_unmerge(struct net *net); 394 395 /* Exported by fib_semantics.c */ 396 int ip_fib_check_default(__be32 gw, struct net_device *dev); 397 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force); 398 int fib_sync_down_addr(struct net_device *dev, __be32 local); 399 int fib_sync_up(struct net_device *dev, unsigned int nh_flags); 400 401 #ifdef CONFIG_IP_ROUTE_MULTIPATH 402 int fib_multipath_hash(const struct fib_info *fi, const struct flowi4 *fl4, 403 const struct sk_buff *skb); 404 #endif 405 void fib_select_multipath(struct fib_result *res, int hash); 406 void fib_select_path(struct net *net, struct fib_result *res, 407 struct flowi4 *fl4, const struct sk_buff *skb); 408 409 /* Exported by fib_trie.c */ 410 void fib_trie_init(void); 411 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias); 412 413 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 414 { 415 #ifdef CONFIG_IP_ROUTE_CLASSID 416 #ifdef CONFIG_IP_MULTIPLE_TABLES 417 u32 rtag; 418 #endif 419 *itag = FIB_RES_NH(*res).nh_tclassid<<16; 420 #ifdef CONFIG_IP_MULTIPLE_TABLES 421 rtag = res->tclassid; 422 if (*itag == 0) 423 *itag = (rtag<<16); 424 *itag |= (rtag>>16); 425 #endif 426 #endif 427 } 428 429 void free_fib_info(struct fib_info *fi); 430 431 static inline void fib_info_hold(struct fib_info *fi) 432 { 433 atomic_inc(&fi->fib_clntref); 434 } 435 436 static inline void fib_info_put(struct fib_info *fi) 437 { 438 if (atomic_dec_and_test(&fi->fib_clntref)) 439 free_fib_info(fi); 440 } 441 442 #ifdef CONFIG_PROC_FS 443 int __net_init fib_proc_init(struct net *net); 444 void __net_exit fib_proc_exit(struct net *net); 445 #else 446 static inline int fib_proc_init(struct net *net) 447 { 448 return 0; 449 } 450 static inline void fib_proc_exit(struct net *net) 451 { 452 } 453 #endif 454 455 #endif /* _NET_FIB_H */ 456