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_notifier.h> 23 #include <net/fib_rules.h> 24 #include <net/inetpeer.h> 25 #include <linux/percpu.h> 26 #include <linux/notifier.h> 27 #include <linux/refcount.h> 28 29 struct fib_config { 30 u8 fc_dst_len; 31 u8 fc_tos; 32 u8 fc_protocol; 33 u8 fc_scope; 34 u8 fc_type; 35 /* 3 bytes unused */ 36 u32 fc_table; 37 __be32 fc_dst; 38 __be32 fc_gw; 39 int fc_oif; 40 u32 fc_flags; 41 u32 fc_priority; 42 __be32 fc_prefsrc; 43 struct nlattr *fc_mx; 44 struct rtnexthop *fc_mp; 45 int fc_mx_len; 46 int fc_mp_len; 47 u32 fc_flow; 48 u32 fc_nlflags; 49 struct nl_info fc_nlinfo; 50 struct nlattr *fc_encap; 51 u16 fc_encap_type; 52 }; 53 54 struct fib_info; 55 struct rtable; 56 57 struct fib_nh_exception { 58 struct fib_nh_exception __rcu *fnhe_next; 59 int fnhe_genid; 60 __be32 fnhe_daddr; 61 u32 fnhe_pmtu; 62 __be32 fnhe_gw; 63 unsigned long fnhe_expires; 64 struct rtable __rcu *fnhe_rth_input; 65 struct rtable __rcu *fnhe_rth_output; 66 unsigned long fnhe_stamp; 67 struct rcu_head rcu; 68 }; 69 70 struct fnhe_hash_bucket { 71 struct fib_nh_exception __rcu *chain; 72 }; 73 74 #define FNHE_HASH_SHIFT 11 75 #define FNHE_HASH_SIZE (1 << FNHE_HASH_SHIFT) 76 #define FNHE_RECLAIM_DEPTH 5 77 78 struct fib_nh { 79 struct net_device *nh_dev; 80 struct hlist_node nh_hash; 81 struct fib_info *nh_parent; 82 unsigned int nh_flags; 83 unsigned char nh_scope; 84 #ifdef CONFIG_IP_ROUTE_MULTIPATH 85 int nh_weight; 86 atomic_t nh_upper_bound; 87 #endif 88 #ifdef CONFIG_IP_ROUTE_CLASSID 89 __u32 nh_tclassid; 90 #endif 91 int nh_oif; 92 __be32 nh_gw; 93 __be32 nh_saddr; 94 int nh_saddr_genid; 95 struct rtable __rcu * __percpu *nh_pcpu_rth_output; 96 struct rtable __rcu *nh_rth_input; 97 struct fnhe_hash_bucket __rcu *nh_exceptions; 98 struct lwtunnel_state *nh_lwtstate; 99 }; 100 101 /* 102 * This structure contains data shared by many of routes. 103 */ 104 105 struct fib_info { 106 struct hlist_node fib_hash; 107 struct hlist_node fib_lhash; 108 struct net *fib_net; 109 int fib_treeref; 110 refcount_t fib_clntref; 111 unsigned int fib_flags; 112 unsigned char fib_dead; 113 unsigned char fib_protocol; 114 unsigned char fib_scope; 115 unsigned char fib_type; 116 __be32 fib_prefsrc; 117 u32 fib_tb_id; 118 u32 fib_priority; 119 struct dst_metrics *fib_metrics; 120 #define fib_mtu fib_metrics->metrics[RTAX_MTU-1] 121 #define fib_window fib_metrics->metrics[RTAX_WINDOW-1] 122 #define fib_rtt fib_metrics->metrics[RTAX_RTT-1] 123 #define fib_advmss fib_metrics->metrics[RTAX_ADVMSS-1] 124 int fib_nhs; 125 struct rcu_head rcu; 126 struct fib_nh fib_nh[0]; 127 #define fib_dev fib_nh[0].nh_dev 128 }; 129 130 131 #ifdef CONFIG_IP_MULTIPLE_TABLES 132 struct fib_rule; 133 #endif 134 135 struct fib_table; 136 struct fib_result { 137 __be32 prefix; 138 unsigned char prefixlen; 139 unsigned char nh_sel; 140 unsigned char type; 141 unsigned char scope; 142 u32 tclassid; 143 struct fib_info *fi; 144 struct fib_table *table; 145 struct hlist_head *fa_head; 146 }; 147 148 struct fib_result_nl { 149 __be32 fl_addr; /* To be looked up*/ 150 u32 fl_mark; 151 unsigned char fl_tos; 152 unsigned char fl_scope; 153 unsigned char tb_id_in; 154 155 unsigned char tb_id; /* Results */ 156 unsigned char prefixlen; 157 unsigned char nh_sel; 158 unsigned char type; 159 unsigned char scope; 160 int err; 161 }; 162 163 #ifdef CONFIG_IP_ROUTE_MULTIPATH 164 #define FIB_RES_NH(res) ((res).fi->fib_nh[(res).nh_sel]) 165 #else /* CONFIG_IP_ROUTE_MULTIPATH */ 166 #define FIB_RES_NH(res) ((res).fi->fib_nh[0]) 167 #endif /* CONFIG_IP_ROUTE_MULTIPATH */ 168 169 #ifdef CONFIG_IP_MULTIPLE_TABLES 170 #define FIB_TABLE_HASHSZ 256 171 #else 172 #define FIB_TABLE_HASHSZ 2 173 #endif 174 175 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh); 176 177 #define FIB_RES_SADDR(net, res) \ 178 ((FIB_RES_NH(res).nh_saddr_genid == \ 179 atomic_read(&(net)->ipv4.dev_addr_genid)) ? \ 180 FIB_RES_NH(res).nh_saddr : \ 181 fib_info_update_nh_saddr((net), &FIB_RES_NH(res))) 182 #define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw) 183 #define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev) 184 #define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif) 185 186 #define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \ 187 FIB_RES_SADDR(net, res)) 188 189 struct fib_entry_notifier_info { 190 struct fib_notifier_info info; /* must be first */ 191 u32 dst; 192 int dst_len; 193 struct fib_info *fi; 194 u8 tos; 195 u8 type; 196 u32 tb_id; 197 }; 198 199 struct fib_nh_notifier_info { 200 struct fib_notifier_info info; /* must be first */ 201 struct fib_nh *fib_nh; 202 }; 203 204 int call_fib4_notifier(struct notifier_block *nb, struct net *net, 205 enum fib_event_type event_type, 206 struct fib_notifier_info *info); 207 int call_fib4_notifiers(struct net *net, enum fib_event_type event_type, 208 struct fib_notifier_info *info); 209 210 int __net_init fib4_notifier_init(struct net *net); 211 void __net_exit fib4_notifier_exit(struct net *net); 212 213 void fib_notify(struct net *net, struct notifier_block *nb); 214 215 struct fib_table { 216 struct hlist_node tb_hlist; 217 u32 tb_id; 218 int tb_num_default; 219 struct rcu_head rcu; 220 unsigned long *tb_data; 221 unsigned long __data[0]; 222 }; 223 224 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 225 struct fib_result *res, int fib_flags); 226 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *, 227 struct netlink_ext_ack *extack); 228 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *, 229 struct netlink_ext_ack *extack); 230 int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 231 struct netlink_callback *cb); 232 int fib_table_flush(struct net *net, struct fib_table *table); 233 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb); 234 void fib_table_flush_external(struct fib_table *table); 235 void fib_free_table(struct fib_table *tb); 236 237 #ifndef CONFIG_IP_MULTIPLE_TABLES 238 239 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1)) 240 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1)) 241 242 static inline struct fib_table *fib_get_table(struct net *net, u32 id) 243 { 244 struct hlist_node *tb_hlist; 245 struct hlist_head *ptr; 246 247 ptr = id == RT_TABLE_LOCAL ? 248 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] : 249 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]; 250 251 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr)); 252 253 return hlist_entry(tb_hlist, struct fib_table, tb_hlist); 254 } 255 256 static inline struct fib_table *fib_new_table(struct net *net, u32 id) 257 { 258 return fib_get_table(net, id); 259 } 260 261 static inline int fib_lookup(struct net *net, const struct flowi4 *flp, 262 struct fib_result *res, unsigned int flags) 263 { 264 struct fib_table *tb; 265 int err = -ENETUNREACH; 266 267 rcu_read_lock(); 268 269 tb = fib_get_table(net, RT_TABLE_MAIN); 270 if (tb) 271 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF); 272 273 if (err == -EAGAIN) 274 err = -ENETUNREACH; 275 276 rcu_read_unlock(); 277 278 return err; 279 } 280 281 static inline bool fib4_rule_default(const struct fib_rule *rule) 282 { 283 return true; 284 } 285 286 static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb) 287 { 288 return 0; 289 } 290 291 static inline unsigned int fib4_rules_seq_read(struct net *net) 292 { 293 return 0; 294 } 295 296 #else /* CONFIG_IP_MULTIPLE_TABLES */ 297 int __net_init fib4_rules_init(struct net *net); 298 void __net_exit fib4_rules_exit(struct net *net); 299 300 struct fib_table *fib_new_table(struct net *net, u32 id); 301 struct fib_table *fib_get_table(struct net *net, u32 id); 302 303 int __fib_lookup(struct net *net, struct flowi4 *flp, 304 struct fib_result *res, unsigned int flags); 305 306 static inline int fib_lookup(struct net *net, struct flowi4 *flp, 307 struct fib_result *res, unsigned int flags) 308 { 309 struct fib_table *tb; 310 int err = -ENETUNREACH; 311 312 flags |= FIB_LOOKUP_NOREF; 313 if (net->ipv4.fib_has_custom_rules) 314 return __fib_lookup(net, flp, res, flags); 315 316 rcu_read_lock(); 317 318 res->tclassid = 0; 319 320 tb = rcu_dereference_rtnl(net->ipv4.fib_main); 321 if (tb) 322 err = fib_table_lookup(tb, flp, res, flags); 323 324 if (!err) 325 goto out; 326 327 tb = rcu_dereference_rtnl(net->ipv4.fib_default); 328 if (tb) 329 err = fib_table_lookup(tb, flp, res, flags); 330 331 out: 332 if (err == -EAGAIN) 333 err = -ENETUNREACH; 334 335 rcu_read_unlock(); 336 337 return err; 338 } 339 340 bool fib4_rule_default(const struct fib_rule *rule); 341 int fib4_rules_dump(struct net *net, struct notifier_block *nb); 342 unsigned int fib4_rules_seq_read(struct net *net); 343 344 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 345 346 /* Exported by fib_frontend.c */ 347 extern const struct nla_policy rtm_ipv4_policy[]; 348 void ip_fib_init(void); 349 __be32 fib_compute_spec_dst(struct sk_buff *skb); 350 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 351 u8 tos, int oif, struct net_device *dev, 352 struct in_device *idev, u32 *itag); 353 #ifdef CONFIG_IP_ROUTE_CLASSID 354 static inline int fib_num_tclassid_users(struct net *net) 355 { 356 return net->ipv4.fib_num_tclassid_users; 357 } 358 #else 359 static inline int fib_num_tclassid_users(struct net *net) 360 { 361 return 0; 362 } 363 #endif 364 int fib_unmerge(struct net *net); 365 366 /* Exported by fib_semantics.c */ 367 int ip_fib_check_default(__be32 gw, struct net_device *dev); 368 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force); 369 int fib_sync_down_addr(struct net_device *dev, __be32 local); 370 int fib_sync_up(struct net_device *dev, unsigned int nh_flags); 371 372 #ifdef CONFIG_IP_ROUTE_MULTIPATH 373 int fib_multipath_hash(const struct fib_info *fi, const struct flowi4 *fl4, 374 const struct sk_buff *skb); 375 #endif 376 void fib_select_multipath(struct fib_result *res, int hash); 377 void fib_select_path(struct net *net, struct fib_result *res, 378 struct flowi4 *fl4, const struct sk_buff *skb); 379 380 /* Exported by fib_trie.c */ 381 void fib_trie_init(void); 382 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias); 383 384 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 385 { 386 #ifdef CONFIG_IP_ROUTE_CLASSID 387 #ifdef CONFIG_IP_MULTIPLE_TABLES 388 u32 rtag; 389 #endif 390 *itag = FIB_RES_NH(*res).nh_tclassid<<16; 391 #ifdef CONFIG_IP_MULTIPLE_TABLES 392 rtag = res->tclassid; 393 if (*itag == 0) 394 *itag = (rtag<<16); 395 *itag |= (rtag>>16); 396 #endif 397 #endif 398 } 399 400 void free_fib_info(struct fib_info *fi); 401 402 static inline void fib_info_hold(struct fib_info *fi) 403 { 404 refcount_inc(&fi->fib_clntref); 405 } 406 407 static inline void fib_info_put(struct fib_info *fi) 408 { 409 if (refcount_dec_and_test(&fi->fib_clntref)) 410 free_fib_info(fi); 411 } 412 413 #ifdef CONFIG_PROC_FS 414 int __net_init fib_proc_init(struct net *net); 415 void __net_exit fib_proc_exit(struct net *net); 416 #else 417 static inline int fib_proc_init(struct net *net) 418 { 419 return 0; 420 } 421 static inline void fib_proc_exit(struct net *net) 422 { 423 } 424 #endif 425 426 #endif /* _NET_FIB_H */ 427