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 bool fnhe_mtu_locked; 63 __be32 fnhe_gw; 64 unsigned long fnhe_expires; 65 struct rtable __rcu *fnhe_rth_input; 66 struct rtable __rcu *fnhe_rth_output; 67 unsigned long fnhe_stamp; 68 struct rcu_head rcu; 69 }; 70 71 struct fnhe_hash_bucket { 72 struct fib_nh_exception __rcu *chain; 73 }; 74 75 #define FNHE_HASH_SHIFT 11 76 #define FNHE_HASH_SIZE (1 << FNHE_HASH_SHIFT) 77 #define FNHE_RECLAIM_DEPTH 5 78 79 struct fib_nh { 80 struct net_device *nh_dev; 81 struct hlist_node nh_hash; 82 struct fib_info *nh_parent; 83 unsigned int nh_flags; 84 unsigned char nh_scope; 85 #ifdef CONFIG_IP_ROUTE_MULTIPATH 86 int nh_weight; 87 atomic_t nh_upper_bound; 88 #endif 89 #ifdef CONFIG_IP_ROUTE_CLASSID 90 __u32 nh_tclassid; 91 #endif 92 int nh_oif; 93 __be32 nh_gw; 94 __be32 nh_saddr; 95 int nh_saddr_genid; 96 struct rtable __rcu * __percpu *nh_pcpu_rth_output; 97 struct rtable __rcu *nh_rth_input; 98 struct fnhe_hash_bucket __rcu *nh_exceptions; 99 struct lwtunnel_state *nh_lwtstate; 100 }; 101 102 /* 103 * This structure contains data shared by many of routes. 104 */ 105 106 struct fib_info { 107 struct hlist_node fib_hash; 108 struct hlist_node fib_lhash; 109 struct net *fib_net; 110 int fib_treeref; 111 refcount_t fib_clntref; 112 unsigned int fib_flags; 113 unsigned char fib_dead; 114 unsigned char fib_protocol; 115 unsigned char fib_scope; 116 unsigned char fib_type; 117 __be32 fib_prefsrc; 118 u32 fib_tb_id; 119 u32 fib_priority; 120 struct dst_metrics *fib_metrics; 121 #define fib_mtu fib_metrics->metrics[RTAX_MTU-1] 122 #define fib_window fib_metrics->metrics[RTAX_WINDOW-1] 123 #define fib_rtt fib_metrics->metrics[RTAX_RTT-1] 124 #define fib_advmss fib_metrics->metrics[RTAX_ADVMSS-1] 125 int fib_nhs; 126 struct rcu_head rcu; 127 struct fib_nh fib_nh[0]; 128 #define fib_dev fib_nh[0].nh_dev 129 }; 130 131 132 #ifdef CONFIG_IP_MULTIPLE_TABLES 133 struct fib_rule; 134 #endif 135 136 struct fib_table; 137 struct fib_result { 138 __be32 prefix; 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 #define FIB_RES_SADDR(net, res) \ 179 ((FIB_RES_NH(res).nh_saddr_genid == \ 180 atomic_read(&(net)->ipv4.dev_addr_genid)) ? \ 181 FIB_RES_NH(res).nh_saddr : \ 182 fib_info_update_nh_saddr((net), &FIB_RES_NH(res))) 183 #define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw) 184 #define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev) 185 #define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif) 186 187 #define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \ 188 FIB_RES_SADDR(net, res)) 189 190 struct fib_entry_notifier_info { 191 struct fib_notifier_info info; /* must be first */ 192 u32 dst; 193 int dst_len; 194 struct fib_info *fi; 195 u8 tos; 196 u8 type; 197 u32 tb_id; 198 }; 199 200 struct fib_nh_notifier_info { 201 struct fib_notifier_info info; /* must be first */ 202 struct fib_nh *fib_nh; 203 }; 204 205 int call_fib4_notifier(struct notifier_block *nb, struct net *net, 206 enum fib_event_type event_type, 207 struct fib_notifier_info *info); 208 int call_fib4_notifiers(struct net *net, enum fib_event_type event_type, 209 struct fib_notifier_info *info); 210 211 int __net_init fib4_notifier_init(struct net *net); 212 void __net_exit fib4_notifier_exit(struct net *net); 213 214 void fib_notify(struct net *net, struct notifier_block *nb); 215 216 struct fib_table { 217 struct hlist_node tb_hlist; 218 u32 tb_id; 219 int tb_num_default; 220 struct rcu_head rcu; 221 unsigned long *tb_data; 222 unsigned long __data[0]; 223 }; 224 225 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 226 struct fib_result *res, int fib_flags); 227 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *, 228 struct netlink_ext_ack *extack); 229 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *, 230 struct netlink_ext_ack *extack); 231 int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 232 struct netlink_callback *cb); 233 int fib_table_flush(struct net *net, struct fib_table *table); 234 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb); 235 void fib_table_flush_external(struct fib_table *table); 236 void fib_free_table(struct fib_table *tb); 237 238 #ifndef CONFIG_IP_MULTIPLE_TABLES 239 240 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1)) 241 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1)) 242 243 static inline struct fib_table *fib_get_table(struct net *net, u32 id) 244 { 245 struct hlist_node *tb_hlist; 246 struct hlist_head *ptr; 247 248 ptr = id == RT_TABLE_LOCAL ? 249 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] : 250 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]; 251 252 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr)); 253 254 return hlist_entry(tb_hlist, struct fib_table, tb_hlist); 255 } 256 257 static inline struct fib_table *fib_new_table(struct net *net, u32 id) 258 { 259 return fib_get_table(net, id); 260 } 261 262 static inline int fib_lookup(struct net *net, const struct flowi4 *flp, 263 struct fib_result *res, unsigned int flags) 264 { 265 struct fib_table *tb; 266 int err = -ENETUNREACH; 267 268 rcu_read_lock(); 269 270 tb = fib_get_table(net, RT_TABLE_MAIN); 271 if (tb) 272 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF); 273 274 if (err == -EAGAIN) 275 err = -ENETUNREACH; 276 277 rcu_read_unlock(); 278 279 return err; 280 } 281 282 static inline bool fib4_rule_default(const struct fib_rule *rule) 283 { 284 return true; 285 } 286 287 static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb) 288 { 289 return 0; 290 } 291 292 static inline unsigned int fib4_rules_seq_read(struct net *net) 293 { 294 return 0; 295 } 296 297 static inline bool fib4_rules_early_flow_dissect(struct net *net, 298 struct sk_buff *skb, 299 struct flowi4 *fl4, 300 struct flow_keys *flkeys) 301 { 302 return false; 303 } 304 #else /* CONFIG_IP_MULTIPLE_TABLES */ 305 int __net_init fib4_rules_init(struct net *net); 306 void __net_exit fib4_rules_exit(struct net *net); 307 308 struct fib_table *fib_new_table(struct net *net, u32 id); 309 struct fib_table *fib_get_table(struct net *net, u32 id); 310 311 int __fib_lookup(struct net *net, struct flowi4 *flp, 312 struct fib_result *res, unsigned int flags); 313 314 static inline int fib_lookup(struct net *net, struct flowi4 *flp, 315 struct fib_result *res, unsigned int flags) 316 { 317 struct fib_table *tb; 318 int err = -ENETUNREACH; 319 320 flags |= FIB_LOOKUP_NOREF; 321 if (net->ipv4.fib_has_custom_rules) 322 return __fib_lookup(net, flp, res, flags); 323 324 rcu_read_lock(); 325 326 res->tclassid = 0; 327 328 tb = rcu_dereference_rtnl(net->ipv4.fib_main); 329 if (tb) 330 err = fib_table_lookup(tb, flp, res, flags); 331 332 if (!err) 333 goto out; 334 335 tb = rcu_dereference_rtnl(net->ipv4.fib_default); 336 if (tb) 337 err = fib_table_lookup(tb, flp, res, flags); 338 339 out: 340 if (err == -EAGAIN) 341 err = -ENETUNREACH; 342 343 rcu_read_unlock(); 344 345 return err; 346 } 347 348 bool fib4_rule_default(const struct fib_rule *rule); 349 int fib4_rules_dump(struct net *net, struct notifier_block *nb); 350 unsigned int fib4_rules_seq_read(struct net *net); 351 352 static inline bool fib4_rules_early_flow_dissect(struct net *net, 353 struct sk_buff *skb, 354 struct flowi4 *fl4, 355 struct flow_keys *flkeys) 356 { 357 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 358 359 if (!net->ipv4.fib_rules_require_fldissect) 360 return false; 361 362 skb_flow_dissect_flow_keys(skb, flkeys, flag); 363 fl4->fl4_sport = flkeys->ports.src; 364 fl4->fl4_dport = flkeys->ports.dst; 365 fl4->flowi4_proto = flkeys->basic.ip_proto; 366 367 return true; 368 } 369 370 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 371 372 /* Exported by fib_frontend.c */ 373 extern const struct nla_policy rtm_ipv4_policy[]; 374 void ip_fib_init(void); 375 __be32 fib_compute_spec_dst(struct sk_buff *skb); 376 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 377 u8 tos, int oif, struct net_device *dev, 378 struct in_device *idev, u32 *itag); 379 #ifdef CONFIG_IP_ROUTE_CLASSID 380 static inline int fib_num_tclassid_users(struct net *net) 381 { 382 return net->ipv4.fib_num_tclassid_users; 383 } 384 #else 385 static inline int fib_num_tclassid_users(struct net *net) 386 { 387 return 0; 388 } 389 #endif 390 int fib_unmerge(struct net *net); 391 392 /* Exported by fib_semantics.c */ 393 int ip_fib_check_default(__be32 gw, struct net_device *dev); 394 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force); 395 int fib_sync_down_addr(struct net_device *dev, __be32 local); 396 int fib_sync_up(struct net_device *dev, unsigned int nh_flags); 397 398 #ifdef CONFIG_IP_ROUTE_MULTIPATH 399 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 400 const struct sk_buff *skb, struct flow_keys *flkeys); 401 #endif 402 void fib_select_multipath(struct fib_result *res, int hash); 403 void fib_select_path(struct net *net, struct fib_result *res, 404 struct flowi4 *fl4, const struct sk_buff *skb); 405 406 /* Exported by fib_trie.c */ 407 void fib_trie_init(void); 408 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias); 409 410 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 411 { 412 #ifdef CONFIG_IP_ROUTE_CLASSID 413 #ifdef CONFIG_IP_MULTIPLE_TABLES 414 u32 rtag; 415 #endif 416 *itag = FIB_RES_NH(*res).nh_tclassid<<16; 417 #ifdef CONFIG_IP_MULTIPLE_TABLES 418 rtag = res->tclassid; 419 if (*itag == 0) 420 *itag = (rtag<<16); 421 *itag |= (rtag>>16); 422 #endif 423 #endif 424 } 425 426 void free_fib_info(struct fib_info *fi); 427 428 static inline void fib_info_hold(struct fib_info *fi) 429 { 430 refcount_inc(&fi->fib_clntref); 431 } 432 433 static inline void fib_info_put(struct fib_info *fi) 434 { 435 if (refcount_dec_and_test(&fi->fib_clntref)) 436 free_fib_info(fi); 437 } 438 439 #ifdef CONFIG_PROC_FS 440 int __net_init fib_proc_init(struct net *net); 441 void __net_exit fib_proc_exit(struct net *net); 442 #else 443 static inline int fib_proc_init(struct net *net) 444 { 445 return 0; 446 } 447 static inline void fib_proc_exit(struct net *net) 448 { 449 } 450 #endif 451 452 #endif /* _NET_FIB_H */ 453