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 #ifdef CONFIG_IP_ROUTE_MULTIPATH 126 int fib_weight; 127 #endif 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 #define FIB_RES_SADDR(net, res) \ 181 ((FIB_RES_NH(res).nh_saddr_genid == \ 182 atomic_read(&(net)->ipv4.dev_addr_genid)) ? \ 183 FIB_RES_NH(res).nh_saddr : \ 184 fib_info_update_nh_saddr((net), &FIB_RES_NH(res))) 185 #define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw) 186 #define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev) 187 #define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif) 188 189 #define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \ 190 FIB_RES_SADDR(net, res)) 191 192 struct fib_entry_notifier_info { 193 struct fib_notifier_info info; /* must be first */ 194 u32 dst; 195 int dst_len; 196 struct fib_info *fi; 197 u8 tos; 198 u8 type; 199 u32 tb_id; 200 }; 201 202 struct fib_nh_notifier_info { 203 struct fib_notifier_info info; /* must be first */ 204 struct fib_nh *fib_nh; 205 }; 206 207 int call_fib4_notifier(struct notifier_block *nb, struct net *net, 208 enum fib_event_type event_type, 209 struct fib_notifier_info *info); 210 int call_fib4_notifiers(struct net *net, enum fib_event_type event_type, 211 struct fib_notifier_info *info); 212 213 int __net_init fib4_notifier_init(struct net *net); 214 void __net_exit fib4_notifier_exit(struct net *net); 215 216 void fib_notify(struct net *net, struct notifier_block *nb); 217 218 struct fib_table { 219 struct hlist_node tb_hlist; 220 u32 tb_id; 221 int tb_num_default; 222 struct rcu_head rcu; 223 unsigned long *tb_data; 224 unsigned long __data[0]; 225 }; 226 227 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 228 struct fib_result *res, int fib_flags); 229 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *, 230 struct netlink_ext_ack *extack); 231 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *, 232 struct netlink_ext_ack *extack); 233 int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 234 struct netlink_callback *cb); 235 int fib_table_flush(struct net *net, struct fib_table *table); 236 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb); 237 void fib_table_flush_external(struct fib_table *table); 238 void fib_free_table(struct fib_table *tb); 239 240 #ifndef CONFIG_IP_MULTIPLE_TABLES 241 242 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1)) 243 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1)) 244 245 static inline struct fib_table *fib_get_table(struct net *net, u32 id) 246 { 247 struct hlist_node *tb_hlist; 248 struct hlist_head *ptr; 249 250 ptr = id == RT_TABLE_LOCAL ? 251 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] : 252 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]; 253 254 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr)); 255 256 return hlist_entry(tb_hlist, struct fib_table, tb_hlist); 257 } 258 259 static inline struct fib_table *fib_new_table(struct net *net, u32 id) 260 { 261 return fib_get_table(net, id); 262 } 263 264 static inline int fib_lookup(struct net *net, const struct flowi4 *flp, 265 struct fib_result *res, unsigned int flags) 266 { 267 struct fib_table *tb; 268 int err = -ENETUNREACH; 269 270 rcu_read_lock(); 271 272 tb = fib_get_table(net, RT_TABLE_MAIN); 273 if (tb) 274 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF); 275 276 if (err == -EAGAIN) 277 err = -ENETUNREACH; 278 279 rcu_read_unlock(); 280 281 return err; 282 } 283 284 static inline bool fib4_rule_default(const struct fib_rule *rule) 285 { 286 return true; 287 } 288 289 static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb) 290 { 291 return 0; 292 } 293 294 static inline unsigned int fib4_rules_seq_read(struct net *net) 295 { 296 return 0; 297 } 298 299 #else /* CONFIG_IP_MULTIPLE_TABLES */ 300 int __net_init fib4_rules_init(struct net *net); 301 void __net_exit fib4_rules_exit(struct net *net); 302 303 struct fib_table *fib_new_table(struct net *net, u32 id); 304 struct fib_table *fib_get_table(struct net *net, u32 id); 305 306 int __fib_lookup(struct net *net, struct flowi4 *flp, 307 struct fib_result *res, unsigned int flags); 308 309 static inline int fib_lookup(struct net *net, struct flowi4 *flp, 310 struct fib_result *res, unsigned int flags) 311 { 312 struct fib_table *tb; 313 int err = -ENETUNREACH; 314 315 flags |= FIB_LOOKUP_NOREF; 316 if (net->ipv4.fib_has_custom_rules) 317 return __fib_lookup(net, flp, res, flags); 318 319 rcu_read_lock(); 320 321 res->tclassid = 0; 322 323 tb = rcu_dereference_rtnl(net->ipv4.fib_main); 324 if (tb) 325 err = fib_table_lookup(tb, flp, res, flags); 326 327 if (!err) 328 goto out; 329 330 tb = rcu_dereference_rtnl(net->ipv4.fib_default); 331 if (tb) 332 err = fib_table_lookup(tb, flp, res, flags); 333 334 out: 335 if (err == -EAGAIN) 336 err = -ENETUNREACH; 337 338 rcu_read_unlock(); 339 340 return err; 341 } 342 343 bool fib4_rule_default(const struct fib_rule *rule); 344 int fib4_rules_dump(struct net *net, struct notifier_block *nb); 345 unsigned int fib4_rules_seq_read(struct net *net); 346 347 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 348 349 /* Exported by fib_frontend.c */ 350 extern const struct nla_policy rtm_ipv4_policy[]; 351 void ip_fib_init(void); 352 __be32 fib_compute_spec_dst(struct sk_buff *skb); 353 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 354 u8 tos, int oif, struct net_device *dev, 355 struct in_device *idev, u32 *itag); 356 #ifdef CONFIG_IP_ROUTE_CLASSID 357 static inline int fib_num_tclassid_users(struct net *net) 358 { 359 return net->ipv4.fib_num_tclassid_users; 360 } 361 #else 362 static inline int fib_num_tclassid_users(struct net *net) 363 { 364 return 0; 365 } 366 #endif 367 int fib_unmerge(struct net *net); 368 369 /* Exported by fib_semantics.c */ 370 int ip_fib_check_default(__be32 gw, struct net_device *dev); 371 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force); 372 int fib_sync_down_addr(struct net_device *dev, __be32 local); 373 int fib_sync_up(struct net_device *dev, unsigned int nh_flags); 374 375 #ifdef CONFIG_IP_ROUTE_MULTIPATH 376 int fib_multipath_hash(const struct fib_info *fi, const struct flowi4 *fl4, 377 const struct sk_buff *skb); 378 #endif 379 void fib_select_multipath(struct fib_result *res, int hash); 380 void fib_select_path(struct net *net, struct fib_result *res, 381 struct flowi4 *fl4, const struct sk_buff *skb); 382 383 /* Exported by fib_trie.c */ 384 void fib_trie_init(void); 385 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias); 386 387 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 388 { 389 #ifdef CONFIG_IP_ROUTE_CLASSID 390 #ifdef CONFIG_IP_MULTIPLE_TABLES 391 u32 rtag; 392 #endif 393 *itag = FIB_RES_NH(*res).nh_tclassid<<16; 394 #ifdef CONFIG_IP_MULTIPLE_TABLES 395 rtag = res->tclassid; 396 if (*itag == 0) 397 *itag = (rtag<<16); 398 *itag |= (rtag>>16); 399 #endif 400 #endif 401 } 402 403 void free_fib_info(struct fib_info *fi); 404 405 static inline void fib_info_hold(struct fib_info *fi) 406 { 407 refcount_inc(&fi->fib_clntref); 408 } 409 410 static inline void fib_info_put(struct fib_info *fi) 411 { 412 if (refcount_dec_and_test(&fi->fib_clntref)) 413 free_fib_info(fi); 414 } 415 416 #ifdef CONFIG_PROC_FS 417 int __net_init fib_proc_init(struct net *net); 418 void __net_exit fib_proc_exit(struct net *net); 419 #else 420 static inline int fib_proc_init(struct net *net) 421 { 422 return 0; 423 } 424 static inline void fib_proc_exit(struct net *net) 425 { 426 } 427 #endif 428 429 #endif /* _NET_FIB_H */ 430