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 u8 fc_gw_family; 36 /* 2 bytes unused */ 37 u32 fc_table; 38 __be32 fc_dst; 39 union { 40 __be32 fc_gw4; 41 struct in6_addr fc_gw6; 42 }; 43 int fc_oif; 44 u32 fc_flags; 45 u32 fc_priority; 46 __be32 fc_prefsrc; 47 struct nlattr *fc_mx; 48 struct rtnexthop *fc_mp; 49 int fc_mx_len; 50 int fc_mp_len; 51 u32 fc_flow; 52 u32 fc_nlflags; 53 struct nl_info fc_nlinfo; 54 struct nlattr *fc_encap; 55 u16 fc_encap_type; 56 }; 57 58 struct fib_info; 59 struct rtable; 60 61 struct fib_nh_exception { 62 struct fib_nh_exception __rcu *fnhe_next; 63 int fnhe_genid; 64 __be32 fnhe_daddr; 65 u32 fnhe_pmtu; 66 bool fnhe_mtu_locked; 67 __be32 fnhe_gw; 68 unsigned long fnhe_expires; 69 struct rtable __rcu *fnhe_rth_input; 70 struct rtable __rcu *fnhe_rth_output; 71 unsigned long fnhe_stamp; 72 struct rcu_head rcu; 73 }; 74 75 struct fnhe_hash_bucket { 76 struct fib_nh_exception __rcu *chain; 77 }; 78 79 #define FNHE_HASH_SHIFT 11 80 #define FNHE_HASH_SIZE (1 << FNHE_HASH_SHIFT) 81 #define FNHE_RECLAIM_DEPTH 5 82 83 struct fib_nh_common { 84 struct net_device *nhc_dev; 85 int nhc_oif; 86 unsigned char nhc_scope; 87 u8 nhc_family; 88 u8 nhc_gw_family; 89 unsigned char nhc_flags; 90 struct lwtunnel_state *nhc_lwtstate; 91 92 union { 93 __be32 ipv4; 94 struct in6_addr ipv6; 95 } nhc_gw; 96 97 int nhc_weight; 98 atomic_t nhc_upper_bound; 99 100 /* v4 specific, but allows fib6_nh with v4 routes */ 101 struct rtable __rcu * __percpu *nhc_pcpu_rth_output; 102 struct rtable __rcu *nhc_rth_input; 103 struct fnhe_hash_bucket __rcu *nhc_exceptions; 104 }; 105 106 struct fib_nh { 107 struct fib_nh_common nh_common; 108 struct hlist_node nh_hash; 109 struct fib_info *nh_parent; 110 #ifdef CONFIG_IP_ROUTE_CLASSID 111 __u32 nh_tclassid; 112 #endif 113 __be32 nh_saddr; 114 int nh_saddr_genid; 115 #define fib_nh_family nh_common.nhc_family 116 #define fib_nh_dev nh_common.nhc_dev 117 #define fib_nh_oif nh_common.nhc_oif 118 #define fib_nh_flags nh_common.nhc_flags 119 #define fib_nh_lws nh_common.nhc_lwtstate 120 #define fib_nh_scope nh_common.nhc_scope 121 #define fib_nh_gw_family nh_common.nhc_gw_family 122 #define fib_nh_gw4 nh_common.nhc_gw.ipv4 123 #define fib_nh_gw6 nh_common.nhc_gw.ipv6 124 #define fib_nh_weight nh_common.nhc_weight 125 #define fib_nh_upper_bound nh_common.nhc_upper_bound 126 }; 127 128 /* 129 * This structure contains data shared by many of routes. 130 */ 131 132 struct fib_info { 133 struct hlist_node fib_hash; 134 struct hlist_node fib_lhash; 135 struct net *fib_net; 136 int fib_treeref; 137 refcount_t fib_clntref; 138 unsigned int fib_flags; 139 unsigned char fib_dead; 140 unsigned char fib_protocol; 141 unsigned char fib_scope; 142 unsigned char fib_type; 143 __be32 fib_prefsrc; 144 u32 fib_tb_id; 145 u32 fib_priority; 146 struct dst_metrics *fib_metrics; 147 #define fib_mtu fib_metrics->metrics[RTAX_MTU-1] 148 #define fib_window fib_metrics->metrics[RTAX_WINDOW-1] 149 #define fib_rtt fib_metrics->metrics[RTAX_RTT-1] 150 #define fib_advmss fib_metrics->metrics[RTAX_ADVMSS-1] 151 int fib_nhs; 152 bool fib_nh_is_v6; 153 bool nh_updated; 154 struct rcu_head rcu; 155 struct fib_nh fib_nh[0]; 156 #define fib_dev fib_nh[0].fib_nh_dev 157 }; 158 159 160 #ifdef CONFIG_IP_MULTIPLE_TABLES 161 struct fib_rule; 162 #endif 163 164 struct fib_table; 165 struct fib_result { 166 __be32 prefix; 167 unsigned char prefixlen; 168 unsigned char nh_sel; 169 unsigned char type; 170 unsigned char scope; 171 u32 tclassid; 172 struct fib_nh_common *nhc; 173 struct fib_info *fi; 174 struct fib_table *table; 175 struct hlist_head *fa_head; 176 }; 177 178 struct fib_result_nl { 179 __be32 fl_addr; /* To be looked up*/ 180 u32 fl_mark; 181 unsigned char fl_tos; 182 unsigned char fl_scope; 183 unsigned char tb_id_in; 184 185 unsigned char tb_id; /* Results */ 186 unsigned char prefixlen; 187 unsigned char nh_sel; 188 unsigned char type; 189 unsigned char scope; 190 int err; 191 }; 192 193 static inline struct fib_nh_common *fib_info_nhc(struct fib_info *fi, int nhsel) 194 { 195 return &fi->fib_nh[nhsel].nh_common; 196 } 197 198 #ifdef CONFIG_IP_MULTIPLE_TABLES 199 #define FIB_TABLE_HASHSZ 256 200 #else 201 #define FIB_TABLE_HASHSZ 2 202 #endif 203 204 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh, 205 unsigned char scope); 206 __be32 fib_result_prefsrc(struct net *net, struct fib_result *res); 207 208 #define FIB_RES_NHC(res) ((res).nhc) 209 #define FIB_RES_DEV(res) (FIB_RES_NHC(res)->nhc_dev) 210 #define FIB_RES_OIF(res) (FIB_RES_NHC(res)->nhc_oif) 211 212 struct fib_entry_notifier_info { 213 struct fib_notifier_info info; /* must be first */ 214 u32 dst; 215 int dst_len; 216 struct fib_info *fi; 217 u8 tos; 218 u8 type; 219 u32 tb_id; 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 int call_fib4_notifier(struct notifier_block *nb, struct net *net, 228 enum fib_event_type event_type, 229 struct fib_notifier_info *info); 230 int call_fib4_notifiers(struct net *net, enum fib_event_type event_type, 231 struct fib_notifier_info *info); 232 233 int __net_init fib4_notifier_init(struct net *net); 234 void __net_exit fib4_notifier_exit(struct net *net); 235 236 void fib_info_notify_update(struct net *net, struct nl_info *info); 237 void fib_notify(struct net *net, struct notifier_block *nb); 238 239 struct fib_table { 240 struct hlist_node tb_hlist; 241 u32 tb_id; 242 int tb_num_default; 243 struct rcu_head rcu; 244 unsigned long *tb_data; 245 unsigned long __data[0]; 246 }; 247 248 struct fib_dump_filter { 249 u32 table_id; 250 /* filter_set is an optimization that an entry is set */ 251 bool filter_set; 252 bool dump_all_families; 253 unsigned char protocol; 254 unsigned char rt_type; 255 unsigned int flags; 256 struct net_device *dev; 257 }; 258 259 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 260 struct fib_result *res, int fib_flags); 261 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *, 262 struct netlink_ext_ack *extack); 263 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *, 264 struct netlink_ext_ack *extack); 265 int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 266 struct netlink_callback *cb, struct fib_dump_filter *filter); 267 int fib_table_flush(struct net *net, struct fib_table *table, bool flush_all); 268 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb); 269 void fib_table_flush_external(struct fib_table *table); 270 void fib_free_table(struct fib_table *tb); 271 272 #ifndef CONFIG_IP_MULTIPLE_TABLES 273 274 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1)) 275 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1)) 276 277 static inline struct fib_table *fib_get_table(struct net *net, u32 id) 278 { 279 struct hlist_node *tb_hlist; 280 struct hlist_head *ptr; 281 282 ptr = id == RT_TABLE_LOCAL ? 283 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] : 284 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]; 285 286 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr)); 287 288 return hlist_entry(tb_hlist, struct fib_table, tb_hlist); 289 } 290 291 static inline struct fib_table *fib_new_table(struct net *net, u32 id) 292 { 293 return fib_get_table(net, id); 294 } 295 296 static inline int fib_lookup(struct net *net, const struct flowi4 *flp, 297 struct fib_result *res, unsigned int flags) 298 { 299 struct fib_table *tb; 300 int err = -ENETUNREACH; 301 302 rcu_read_lock(); 303 304 tb = fib_get_table(net, RT_TABLE_MAIN); 305 if (tb) 306 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF); 307 308 if (err == -EAGAIN) 309 err = -ENETUNREACH; 310 311 rcu_read_unlock(); 312 313 return err; 314 } 315 316 static inline bool fib4_rule_default(const struct fib_rule *rule) 317 { 318 return true; 319 } 320 321 static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb) 322 { 323 return 0; 324 } 325 326 static inline unsigned int fib4_rules_seq_read(struct net *net) 327 { 328 return 0; 329 } 330 331 static inline bool fib4_rules_early_flow_dissect(struct net *net, 332 struct sk_buff *skb, 333 struct flowi4 *fl4, 334 struct flow_keys *flkeys) 335 { 336 return false; 337 } 338 #else /* CONFIG_IP_MULTIPLE_TABLES */ 339 int __net_init fib4_rules_init(struct net *net); 340 void __net_exit fib4_rules_exit(struct net *net); 341 342 struct fib_table *fib_new_table(struct net *net, u32 id); 343 struct fib_table *fib_get_table(struct net *net, u32 id); 344 345 int __fib_lookup(struct net *net, struct flowi4 *flp, 346 struct fib_result *res, unsigned int flags); 347 348 static inline int fib_lookup(struct net *net, struct flowi4 *flp, 349 struct fib_result *res, unsigned int flags) 350 { 351 struct fib_table *tb; 352 int err = -ENETUNREACH; 353 354 flags |= FIB_LOOKUP_NOREF; 355 if (net->ipv4.fib_has_custom_rules) 356 return __fib_lookup(net, flp, res, flags); 357 358 rcu_read_lock(); 359 360 res->tclassid = 0; 361 362 tb = rcu_dereference_rtnl(net->ipv4.fib_main); 363 if (tb) 364 err = fib_table_lookup(tb, flp, res, flags); 365 366 if (!err) 367 goto out; 368 369 tb = rcu_dereference_rtnl(net->ipv4.fib_default); 370 if (tb) 371 err = fib_table_lookup(tb, flp, res, flags); 372 373 out: 374 if (err == -EAGAIN) 375 err = -ENETUNREACH; 376 377 rcu_read_unlock(); 378 379 return err; 380 } 381 382 bool fib4_rule_default(const struct fib_rule *rule); 383 int fib4_rules_dump(struct net *net, struct notifier_block *nb); 384 unsigned int fib4_rules_seq_read(struct net *net); 385 386 static inline bool fib4_rules_early_flow_dissect(struct net *net, 387 struct sk_buff *skb, 388 struct flowi4 *fl4, 389 struct flow_keys *flkeys) 390 { 391 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 392 393 if (!net->ipv4.fib_rules_require_fldissect) 394 return false; 395 396 skb_flow_dissect_flow_keys(skb, flkeys, flag); 397 fl4->fl4_sport = flkeys->ports.src; 398 fl4->fl4_dport = flkeys->ports.dst; 399 fl4->flowi4_proto = flkeys->basic.ip_proto; 400 401 return true; 402 } 403 404 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 405 406 /* Exported by fib_frontend.c */ 407 extern const struct nla_policy rtm_ipv4_policy[]; 408 void ip_fib_init(void); 409 int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla, 410 struct netlink_ext_ack *extack); 411 __be32 fib_compute_spec_dst(struct sk_buff *skb); 412 bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev); 413 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 414 u8 tos, int oif, struct net_device *dev, 415 struct in_device *idev, u32 *itag); 416 #ifdef CONFIG_IP_ROUTE_CLASSID 417 static inline int fib_num_tclassid_users(struct net *net) 418 { 419 return net->ipv4.fib_num_tclassid_users; 420 } 421 #else 422 static inline int fib_num_tclassid_users(struct net *net) 423 { 424 return 0; 425 } 426 #endif 427 int fib_unmerge(struct net *net); 428 429 /* Exported by fib_semantics.c */ 430 int ip_fib_check_default(__be32 gw, struct net_device *dev); 431 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force); 432 int fib_sync_down_addr(struct net_device *dev, __be32 local); 433 int fib_sync_up(struct net_device *dev, unsigned char nh_flags); 434 void fib_sync_mtu(struct net_device *dev, u32 orig_mtu); 435 void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig); 436 437 #ifdef CONFIG_IP_ROUTE_MULTIPATH 438 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 439 const struct sk_buff *skb, struct flow_keys *flkeys); 440 #endif 441 int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope, 442 struct netlink_ext_ack *extack); 443 void fib_select_multipath(struct fib_result *res, int hash); 444 void fib_select_path(struct net *net, struct fib_result *res, 445 struct flowi4 *fl4, const struct sk_buff *skb); 446 447 int fib_nh_init(struct net *net, struct fib_nh *fib_nh, 448 struct fib_config *cfg, int nh_weight, 449 struct netlink_ext_ack *extack); 450 void fib_nh_release(struct net *net, struct fib_nh *fib_nh); 451 int fib_nh_common_init(struct fib_nh_common *nhc, struct nlattr *fc_encap, 452 u16 fc_encap_type, void *cfg, gfp_t gfp_flags, 453 struct netlink_ext_ack *extack); 454 void fib_nh_common_release(struct fib_nh_common *nhc); 455 456 /* Exported by fib_trie.c */ 457 void fib_trie_init(void); 458 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias); 459 460 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 461 { 462 #ifdef CONFIG_IP_ROUTE_CLASSID 463 struct fib_nh_common *nhc = res->nhc; 464 struct fib_nh *nh = container_of(nhc, struct fib_nh, nh_common); 465 #ifdef CONFIG_IP_MULTIPLE_TABLES 466 u32 rtag; 467 #endif 468 *itag = nh->nh_tclassid << 16; 469 #ifdef CONFIG_IP_MULTIPLE_TABLES 470 rtag = res->tclassid; 471 if (*itag == 0) 472 *itag = (rtag<<16); 473 *itag |= (rtag>>16); 474 #endif 475 #endif 476 } 477 478 void fib_flush(struct net *net); 479 void free_fib_info(struct fib_info *fi); 480 481 static inline void fib_info_hold(struct fib_info *fi) 482 { 483 refcount_inc(&fi->fib_clntref); 484 } 485 486 static inline void fib_info_put(struct fib_info *fi) 487 { 488 if (refcount_dec_and_test(&fi->fib_clntref)) 489 free_fib_info(fi); 490 } 491 492 #ifdef CONFIG_PROC_FS 493 int __net_init fib_proc_init(struct net *net); 494 void __net_exit fib_proc_exit(struct net *net); 495 #else 496 static inline int fib_proc_init(struct net *net) 497 { 498 return 0; 499 } 500 static inline void fib_proc_exit(struct net *net) 501 { 502 } 503 #endif 504 505 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr); 506 507 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 508 struct fib_dump_filter *filter, 509 struct netlink_callback *cb); 510 511 int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nh, 512 unsigned char *flags, bool skip_oif); 513 int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nh, 514 int nh_weight); 515 #endif /* _NET_FIB_H */ 516