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 int nhc_flags; 87 struct lwtunnel_state *nhc_lwtstate; 88 unsigned char nhc_scope; 89 u8 nhc_family; 90 u8 nhc_gw_family; 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 }; 100 101 struct fib_nh { 102 struct fib_nh_common nh_common; 103 struct hlist_node nh_hash; 104 struct fib_info *nh_parent; 105 #ifdef CONFIG_IP_ROUTE_CLASSID 106 __u32 nh_tclassid; 107 #endif 108 __be32 nh_saddr; 109 int nh_saddr_genid; 110 struct rtable __rcu * __percpu *nh_pcpu_rth_output; 111 struct rtable __rcu *nh_rth_input; 112 struct fnhe_hash_bucket __rcu *nh_exceptions; 113 #define fib_nh_family nh_common.nhc_family 114 #define fib_nh_dev nh_common.nhc_dev 115 #define fib_nh_oif nh_common.nhc_oif 116 #define fib_nh_flags nh_common.nhc_flags 117 #define fib_nh_lws nh_common.nhc_lwtstate 118 #define fib_nh_scope nh_common.nhc_scope 119 #define fib_nh_gw_family nh_common.nhc_gw_family 120 #define fib_nh_gw4 nh_common.nhc_gw.ipv4 121 #define fib_nh_gw6 nh_common.nhc_gw.ipv6 122 #define fib_nh_weight nh_common.nhc_weight 123 #define fib_nh_upper_bound nh_common.nhc_upper_bound 124 }; 125 126 /* 127 * This structure contains data shared by many of routes. 128 */ 129 130 struct fib_info { 131 struct hlist_node fib_hash; 132 struct hlist_node fib_lhash; 133 struct net *fib_net; 134 int fib_treeref; 135 refcount_t fib_clntref; 136 unsigned int fib_flags; 137 unsigned char fib_dead; 138 unsigned char fib_protocol; 139 unsigned char fib_scope; 140 unsigned char fib_type; 141 __be32 fib_prefsrc; 142 u32 fib_tb_id; 143 u32 fib_priority; 144 struct dst_metrics *fib_metrics; 145 #define fib_mtu fib_metrics->metrics[RTAX_MTU-1] 146 #define fib_window fib_metrics->metrics[RTAX_WINDOW-1] 147 #define fib_rtt fib_metrics->metrics[RTAX_RTT-1] 148 #define fib_advmss fib_metrics->metrics[RTAX_ADVMSS-1] 149 int fib_nhs; 150 bool fib_nh_is_v6; 151 struct rcu_head rcu; 152 struct fib_nh fib_nh[0]; 153 #define fib_dev fib_nh[0].fib_nh_dev 154 }; 155 156 157 #ifdef CONFIG_IP_MULTIPLE_TABLES 158 struct fib_rule; 159 #endif 160 161 struct fib_table; 162 struct fib_result { 163 __be32 prefix; 164 unsigned char prefixlen; 165 unsigned char nh_sel; 166 unsigned char type; 167 unsigned char scope; 168 u32 tclassid; 169 struct fib_nh_common *nhc; 170 struct fib_info *fi; 171 struct fib_table *table; 172 struct hlist_head *fa_head; 173 }; 174 175 struct fib_result_nl { 176 __be32 fl_addr; /* To be looked up*/ 177 u32 fl_mark; 178 unsigned char fl_tos; 179 unsigned char fl_scope; 180 unsigned char tb_id_in; 181 182 unsigned char tb_id; /* Results */ 183 unsigned char prefixlen; 184 unsigned char nh_sel; 185 unsigned char type; 186 unsigned char scope; 187 int err; 188 }; 189 190 static inline struct fib_nh_common *fib_info_nhc(struct fib_info *fi, int nhsel) 191 { 192 return &fi->fib_nh[nhsel].nh_common; 193 } 194 195 #ifdef CONFIG_IP_MULTIPLE_TABLES 196 #define FIB_TABLE_HASHSZ 256 197 #else 198 #define FIB_TABLE_HASHSZ 2 199 #endif 200 201 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh); 202 __be32 fib_result_prefsrc(struct net *net, struct fib_result *res); 203 204 #define FIB_RES_NHC(res) ((res).nhc) 205 #define FIB_RES_DEV(res) (FIB_RES_NHC(res)->nhc_dev) 206 #define FIB_RES_OIF(res) (FIB_RES_NHC(res)->nhc_oif) 207 208 struct fib_entry_notifier_info { 209 struct fib_notifier_info info; /* must be first */ 210 u32 dst; 211 int dst_len; 212 struct fib_info *fi; 213 u8 tos; 214 u8 type; 215 u32 tb_id; 216 }; 217 218 struct fib_nh_notifier_info { 219 struct fib_notifier_info info; /* must be first */ 220 struct fib_nh *fib_nh; 221 }; 222 223 int call_fib4_notifier(struct notifier_block *nb, struct net *net, 224 enum fib_event_type event_type, 225 struct fib_notifier_info *info); 226 int call_fib4_notifiers(struct net *net, enum fib_event_type event_type, 227 struct fib_notifier_info *info); 228 229 int __net_init fib4_notifier_init(struct net *net); 230 void __net_exit fib4_notifier_exit(struct net *net); 231 232 void fib_notify(struct net *net, struct notifier_block *nb); 233 234 struct fib_table { 235 struct hlist_node tb_hlist; 236 u32 tb_id; 237 int tb_num_default; 238 struct rcu_head rcu; 239 unsigned long *tb_data; 240 unsigned long __data[0]; 241 }; 242 243 struct fib_dump_filter { 244 u32 table_id; 245 /* filter_set is an optimization that an entry is set */ 246 bool filter_set; 247 bool dump_all_families; 248 unsigned char protocol; 249 unsigned char rt_type; 250 unsigned int flags; 251 struct net_device *dev; 252 }; 253 254 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 255 struct fib_result *res, int fib_flags); 256 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *, 257 struct netlink_ext_ack *extack); 258 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *, 259 struct netlink_ext_ack *extack); 260 int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 261 struct netlink_callback *cb, struct fib_dump_filter *filter); 262 int fib_table_flush(struct net *net, struct fib_table *table, bool flush_all); 263 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb); 264 void fib_table_flush_external(struct fib_table *table); 265 void fib_free_table(struct fib_table *tb); 266 267 #ifndef CONFIG_IP_MULTIPLE_TABLES 268 269 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1)) 270 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1)) 271 272 static inline struct fib_table *fib_get_table(struct net *net, u32 id) 273 { 274 struct hlist_node *tb_hlist; 275 struct hlist_head *ptr; 276 277 ptr = id == RT_TABLE_LOCAL ? 278 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] : 279 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]; 280 281 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr)); 282 283 return hlist_entry(tb_hlist, struct fib_table, tb_hlist); 284 } 285 286 static inline struct fib_table *fib_new_table(struct net *net, u32 id) 287 { 288 return fib_get_table(net, id); 289 } 290 291 static inline int fib_lookup(struct net *net, const struct flowi4 *flp, 292 struct fib_result *res, unsigned int flags) 293 { 294 struct fib_table *tb; 295 int err = -ENETUNREACH; 296 297 rcu_read_lock(); 298 299 tb = fib_get_table(net, RT_TABLE_MAIN); 300 if (tb) 301 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF); 302 303 if (err == -EAGAIN) 304 err = -ENETUNREACH; 305 306 rcu_read_unlock(); 307 308 return err; 309 } 310 311 static inline bool fib4_rule_default(const struct fib_rule *rule) 312 { 313 return true; 314 } 315 316 static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb) 317 { 318 return 0; 319 } 320 321 static inline unsigned int fib4_rules_seq_read(struct net *net) 322 { 323 return 0; 324 } 325 326 static inline bool fib4_rules_early_flow_dissect(struct net *net, 327 struct sk_buff *skb, 328 struct flowi4 *fl4, 329 struct flow_keys *flkeys) 330 { 331 return false; 332 } 333 #else /* CONFIG_IP_MULTIPLE_TABLES */ 334 int __net_init fib4_rules_init(struct net *net); 335 void __net_exit fib4_rules_exit(struct net *net); 336 337 struct fib_table *fib_new_table(struct net *net, u32 id); 338 struct fib_table *fib_get_table(struct net *net, u32 id); 339 340 int __fib_lookup(struct net *net, struct flowi4 *flp, 341 struct fib_result *res, unsigned int flags); 342 343 static inline int fib_lookup(struct net *net, struct flowi4 *flp, 344 struct fib_result *res, unsigned int flags) 345 { 346 struct fib_table *tb; 347 int err = -ENETUNREACH; 348 349 flags |= FIB_LOOKUP_NOREF; 350 if (net->ipv4.fib_has_custom_rules) 351 return __fib_lookup(net, flp, res, flags); 352 353 rcu_read_lock(); 354 355 res->tclassid = 0; 356 357 tb = rcu_dereference_rtnl(net->ipv4.fib_main); 358 if (tb) 359 err = fib_table_lookup(tb, flp, res, flags); 360 361 if (!err) 362 goto out; 363 364 tb = rcu_dereference_rtnl(net->ipv4.fib_default); 365 if (tb) 366 err = fib_table_lookup(tb, flp, res, flags); 367 368 out: 369 if (err == -EAGAIN) 370 err = -ENETUNREACH; 371 372 rcu_read_unlock(); 373 374 return err; 375 } 376 377 bool fib4_rule_default(const struct fib_rule *rule); 378 int fib4_rules_dump(struct net *net, struct notifier_block *nb); 379 unsigned int fib4_rules_seq_read(struct net *net); 380 381 static inline bool fib4_rules_early_flow_dissect(struct net *net, 382 struct sk_buff *skb, 383 struct flowi4 *fl4, 384 struct flow_keys *flkeys) 385 { 386 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 387 388 if (!net->ipv4.fib_rules_require_fldissect) 389 return false; 390 391 skb_flow_dissect_flow_keys(skb, flkeys, flag); 392 fl4->fl4_sport = flkeys->ports.src; 393 fl4->fl4_dport = flkeys->ports.dst; 394 fl4->flowi4_proto = flkeys->basic.ip_proto; 395 396 return true; 397 } 398 399 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 400 401 /* Exported by fib_frontend.c */ 402 extern const struct nla_policy rtm_ipv4_policy[]; 403 void ip_fib_init(void); 404 int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla, 405 struct netlink_ext_ack *extack); 406 __be32 fib_compute_spec_dst(struct sk_buff *skb); 407 bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev); 408 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 409 u8 tos, int oif, struct net_device *dev, 410 struct in_device *idev, u32 *itag); 411 #ifdef CONFIG_IP_ROUTE_CLASSID 412 static inline int fib_num_tclassid_users(struct net *net) 413 { 414 return net->ipv4.fib_num_tclassid_users; 415 } 416 #else 417 static inline int fib_num_tclassid_users(struct net *net) 418 { 419 return 0; 420 } 421 #endif 422 int fib_unmerge(struct net *net); 423 424 /* Exported by fib_semantics.c */ 425 int ip_fib_check_default(__be32 gw, struct net_device *dev); 426 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force); 427 int fib_sync_down_addr(struct net_device *dev, __be32 local); 428 int fib_sync_up(struct net_device *dev, unsigned int nh_flags); 429 void fib_sync_mtu(struct net_device *dev, u32 orig_mtu); 430 431 #ifdef CONFIG_IP_ROUTE_MULTIPATH 432 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 433 const struct sk_buff *skb, struct flow_keys *flkeys); 434 #endif 435 void fib_select_multipath(struct fib_result *res, int hash); 436 void fib_select_path(struct net *net, struct fib_result *res, 437 struct flowi4 *fl4, const struct sk_buff *skb); 438 439 int fib_nh_init(struct net *net, struct fib_nh *fib_nh, 440 struct fib_config *cfg, int nh_weight, 441 struct netlink_ext_ack *extack); 442 void fib_nh_release(struct net *net, struct fib_nh *fib_nh); 443 int fib_nh_common_init(struct fib_nh_common *nhc, struct nlattr *fc_encap, 444 u16 fc_encap_type, void *cfg, gfp_t gfp_flags, 445 struct netlink_ext_ack *extack); 446 void fib_nh_common_release(struct fib_nh_common *nhc); 447 448 /* Exported by fib_trie.c */ 449 void fib_trie_init(void); 450 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias); 451 452 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 453 { 454 #ifdef CONFIG_IP_ROUTE_CLASSID 455 struct fib_nh_common *nhc = res->nhc; 456 struct fib_nh *nh = container_of(nhc, struct fib_nh, nh_common); 457 #ifdef CONFIG_IP_MULTIPLE_TABLES 458 u32 rtag; 459 #endif 460 *itag = nh->nh_tclassid << 16; 461 #ifdef CONFIG_IP_MULTIPLE_TABLES 462 rtag = res->tclassid; 463 if (*itag == 0) 464 *itag = (rtag<<16); 465 *itag |= (rtag>>16); 466 #endif 467 #endif 468 } 469 470 void free_fib_info(struct fib_info *fi); 471 472 static inline void fib_info_hold(struct fib_info *fi) 473 { 474 refcount_inc(&fi->fib_clntref); 475 } 476 477 static inline void fib_info_put(struct fib_info *fi) 478 { 479 if (refcount_dec_and_test(&fi->fib_clntref)) 480 free_fib_info(fi); 481 } 482 483 #ifdef CONFIG_PROC_FS 484 int __net_init fib_proc_init(struct net *net); 485 void __net_exit fib_proc_exit(struct net *net); 486 #else 487 static inline int fib_proc_init(struct net *net) 488 { 489 return 0; 490 } 491 static inline void fib_proc_exit(struct net *net) 492 { 493 } 494 #endif 495 496 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr); 497 498 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 499 struct fib_dump_filter *filter, 500 struct netlink_callback *cb); 501 502 int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nh, 503 unsigned int *flags, bool skip_oif); 504 int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nh, 505 int nh_weight); 506 #endif /* _NET_FIB_H */ 507