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 u32 *fib_metrics; 118 #define fib_mtu fib_metrics[RTAX_MTU-1] 119 #define fib_window fib_metrics[RTAX_WINDOW-1] 120 #define fib_rtt fib_metrics[RTAX_RTT-1] 121 #define fib_advmss fib_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_nh_notifier_info { 217 struct fib_notifier_info info; /* must be first */ 218 struct fib_nh *fib_nh; 219 }; 220 221 enum fib_event_type { 222 FIB_EVENT_ENTRY_REPLACE, 223 FIB_EVENT_ENTRY_APPEND, 224 FIB_EVENT_ENTRY_ADD, 225 FIB_EVENT_ENTRY_DEL, 226 FIB_EVENT_RULE_ADD, 227 FIB_EVENT_RULE_DEL, 228 FIB_EVENT_NH_ADD, 229 FIB_EVENT_NH_DEL, 230 }; 231 232 int register_fib_notifier(struct notifier_block *nb, 233 void (*cb)(struct notifier_block *nb)); 234 int unregister_fib_notifier(struct notifier_block *nb); 235 int call_fib_notifiers(struct net *net, enum fib_event_type event_type, 236 struct fib_notifier_info *info); 237 238 struct fib_table { 239 struct hlist_node tb_hlist; 240 u32 tb_id; 241 int tb_num_default; 242 struct rcu_head rcu; 243 unsigned long *tb_data; 244 unsigned long __data[0]; 245 }; 246 247 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 248 struct fib_result *res, int fib_flags); 249 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *); 250 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *); 251 int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 252 struct netlink_callback *cb); 253 int fib_table_flush(struct net *net, struct fib_table *table); 254 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb); 255 void fib_table_flush_external(struct fib_table *table); 256 void fib_free_table(struct fib_table *tb); 257 258 #ifndef CONFIG_IP_MULTIPLE_TABLES 259 260 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1)) 261 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1)) 262 263 static inline struct fib_table *fib_get_table(struct net *net, u32 id) 264 { 265 struct hlist_node *tb_hlist; 266 struct hlist_head *ptr; 267 268 ptr = id == RT_TABLE_LOCAL ? 269 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] : 270 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]; 271 272 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr)); 273 274 return hlist_entry(tb_hlist, struct fib_table, tb_hlist); 275 } 276 277 static inline struct fib_table *fib_new_table(struct net *net, u32 id) 278 { 279 return fib_get_table(net, id); 280 } 281 282 static inline int fib_lookup(struct net *net, const struct flowi4 *flp, 283 struct fib_result *res, unsigned int flags) 284 { 285 struct fib_table *tb; 286 int err = -ENETUNREACH; 287 288 rcu_read_lock(); 289 290 tb = fib_get_table(net, RT_TABLE_MAIN); 291 if (tb) 292 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF); 293 294 if (err == -EAGAIN) 295 err = -ENETUNREACH; 296 297 rcu_read_unlock(); 298 299 return err; 300 } 301 302 #else /* CONFIG_IP_MULTIPLE_TABLES */ 303 int __net_init fib4_rules_init(struct net *net); 304 void __net_exit fib4_rules_exit(struct net *net); 305 306 struct fib_table *fib_new_table(struct net *net, u32 id); 307 struct fib_table *fib_get_table(struct net *net, u32 id); 308 309 int __fib_lookup(struct net *net, struct flowi4 *flp, 310 struct fib_result *res, unsigned int flags); 311 312 static inline int fib_lookup(struct net *net, struct flowi4 *flp, 313 struct fib_result *res, unsigned int flags) 314 { 315 struct fib_table *tb; 316 int err = -ENETUNREACH; 317 318 flags |= FIB_LOOKUP_NOREF; 319 if (net->ipv4.fib_has_custom_rules) 320 return __fib_lookup(net, flp, res, flags); 321 322 rcu_read_lock(); 323 324 res->tclassid = 0; 325 326 tb = rcu_dereference_rtnl(net->ipv4.fib_main); 327 if (tb) 328 err = fib_table_lookup(tb, flp, res, flags); 329 330 if (!err) 331 goto out; 332 333 tb = rcu_dereference_rtnl(net->ipv4.fib_default); 334 if (tb) 335 err = fib_table_lookup(tb, flp, res, flags); 336 337 out: 338 if (err == -EAGAIN) 339 err = -ENETUNREACH; 340 341 rcu_read_unlock(); 342 343 return err; 344 } 345 346 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 347 348 /* Exported by fib_frontend.c */ 349 extern const struct nla_policy rtm_ipv4_policy[]; 350 void ip_fib_init(void); 351 __be32 fib_compute_spec_dst(struct sk_buff *skb); 352 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 353 u8 tos, int oif, struct net_device *dev, 354 struct in_device *idev, u32 *itag); 355 #ifdef CONFIG_IP_ROUTE_CLASSID 356 static inline int fib_num_tclassid_users(struct net *net) 357 { 358 return net->ipv4.fib_num_tclassid_users; 359 } 360 #else 361 static inline int fib_num_tclassid_users(struct net *net) 362 { 363 return 0; 364 } 365 #endif 366 int fib_unmerge(struct net *net); 367 368 /* Exported by fib_semantics.c */ 369 int ip_fib_check_default(__be32 gw, struct net_device *dev); 370 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force); 371 int fib_sync_down_addr(struct net_device *dev, __be32 local); 372 int fib_sync_up(struct net_device *dev, unsigned int nh_flags); 373 374 extern u32 fib_multipath_secret __read_mostly; 375 376 static inline int fib_multipath_hash(__be32 saddr, __be32 daddr) 377 { 378 return jhash_2words((__force u32)saddr, (__force u32)daddr, 379 fib_multipath_secret) >> 1; 380 } 381 382 void fib_select_multipath(struct fib_result *res, int hash); 383 void fib_select_path(struct net *net, struct fib_result *res, 384 struct flowi4 *fl4, int mp_hash); 385 386 /* Exported by fib_trie.c */ 387 void fib_trie_init(void); 388 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias); 389 390 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 391 { 392 #ifdef CONFIG_IP_ROUTE_CLASSID 393 #ifdef CONFIG_IP_MULTIPLE_TABLES 394 u32 rtag; 395 #endif 396 *itag = FIB_RES_NH(*res).nh_tclassid<<16; 397 #ifdef CONFIG_IP_MULTIPLE_TABLES 398 rtag = res->tclassid; 399 if (*itag == 0) 400 *itag = (rtag<<16); 401 *itag |= (rtag>>16); 402 #endif 403 #endif 404 } 405 406 void free_fib_info(struct fib_info *fi); 407 408 static inline void fib_info_hold(struct fib_info *fi) 409 { 410 atomic_inc(&fi->fib_clntref); 411 } 412 413 static inline void fib_info_put(struct fib_info *fi) 414 { 415 if (atomic_dec_and_test(&fi->fib_clntref)) 416 free_fib_info(fi); 417 } 418 419 #ifdef CONFIG_PROC_FS 420 int __net_init fib_proc_init(struct net *net); 421 void __net_exit fib_proc_exit(struct net *net); 422 #else 423 static inline int fib_proc_init(struct net *net) 424 { 425 return 0; 426 } 427 static inline void fib_proc_exit(struct net *net) 428 { 429 } 430 #endif 431 432 #endif /* _NET_FIB_H */ 433