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 struct rcu_head rcu; 154 struct fib_nh fib_nh[0]; 155 #define fib_dev fib_nh[0].fib_nh_dev 156 }; 157 158 159 #ifdef CONFIG_IP_MULTIPLE_TABLES 160 struct fib_rule; 161 #endif 162 163 struct fib_table; 164 struct fib_result { 165 __be32 prefix; 166 unsigned char prefixlen; 167 unsigned char nh_sel; 168 unsigned char type; 169 unsigned char scope; 170 u32 tclassid; 171 struct fib_nh_common *nhc; 172 struct fib_info *fi; 173 struct fib_table *table; 174 struct hlist_head *fa_head; 175 }; 176 177 struct fib_result_nl { 178 __be32 fl_addr; /* To be looked up*/ 179 u32 fl_mark; 180 unsigned char fl_tos; 181 unsigned char fl_scope; 182 unsigned char tb_id_in; 183 184 unsigned char tb_id; /* Results */ 185 unsigned char prefixlen; 186 unsigned char nh_sel; 187 unsigned char type; 188 unsigned char scope; 189 int err; 190 }; 191 192 static inline struct fib_nh_common *fib_info_nhc(struct fib_info *fi, int nhsel) 193 { 194 return &fi->fib_nh[nhsel].nh_common; 195 } 196 197 #ifdef CONFIG_IP_MULTIPLE_TABLES 198 #define FIB_TABLE_HASHSZ 256 199 #else 200 #define FIB_TABLE_HASHSZ 2 201 #endif 202 203 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh); 204 __be32 fib_result_prefsrc(struct net *net, struct fib_result *res); 205 206 #define FIB_RES_NHC(res) ((res).nhc) 207 #define FIB_RES_DEV(res) (FIB_RES_NHC(res)->nhc_dev) 208 #define FIB_RES_OIF(res) (FIB_RES_NHC(res)->nhc_oif) 209 210 struct fib_entry_notifier_info { 211 struct fib_notifier_info info; /* must be first */ 212 u32 dst; 213 int dst_len; 214 struct fib_info *fi; 215 u8 tos; 216 u8 type; 217 u32 tb_id; 218 }; 219 220 struct fib_nh_notifier_info { 221 struct fib_notifier_info info; /* must be first */ 222 struct fib_nh *fib_nh; 223 }; 224 225 int call_fib4_notifier(struct notifier_block *nb, struct net *net, 226 enum fib_event_type event_type, 227 struct fib_notifier_info *info); 228 int call_fib4_notifiers(struct net *net, enum fib_event_type event_type, 229 struct fib_notifier_info *info); 230 231 int __net_init fib4_notifier_init(struct net *net); 232 void __net_exit fib4_notifier_exit(struct net *net); 233 234 void fib_notify(struct net *net, struct notifier_block *nb); 235 236 struct fib_table { 237 struct hlist_node tb_hlist; 238 u32 tb_id; 239 int tb_num_default; 240 struct rcu_head rcu; 241 unsigned long *tb_data; 242 unsigned long __data[0]; 243 }; 244 245 struct fib_dump_filter { 246 u32 table_id; 247 /* filter_set is an optimization that an entry is set */ 248 bool filter_set; 249 bool dump_all_families; 250 unsigned char protocol; 251 unsigned char rt_type; 252 unsigned int flags; 253 struct net_device *dev; 254 }; 255 256 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 257 struct fib_result *res, int fib_flags); 258 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *, 259 struct netlink_ext_ack *extack); 260 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *, 261 struct netlink_ext_ack *extack); 262 int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 263 struct netlink_callback *cb, struct fib_dump_filter *filter); 264 int fib_table_flush(struct net *net, struct fib_table *table, bool flush_all); 265 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb); 266 void fib_table_flush_external(struct fib_table *table); 267 void fib_free_table(struct fib_table *tb); 268 269 #ifndef CONFIG_IP_MULTIPLE_TABLES 270 271 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1)) 272 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1)) 273 274 static inline struct fib_table *fib_get_table(struct net *net, u32 id) 275 { 276 struct hlist_node *tb_hlist; 277 struct hlist_head *ptr; 278 279 ptr = id == RT_TABLE_LOCAL ? 280 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] : 281 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]; 282 283 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr)); 284 285 return hlist_entry(tb_hlist, struct fib_table, tb_hlist); 286 } 287 288 static inline struct fib_table *fib_new_table(struct net *net, u32 id) 289 { 290 return fib_get_table(net, id); 291 } 292 293 static inline int fib_lookup(struct net *net, const struct flowi4 *flp, 294 struct fib_result *res, unsigned int flags) 295 { 296 struct fib_table *tb; 297 int err = -ENETUNREACH; 298 299 rcu_read_lock(); 300 301 tb = fib_get_table(net, RT_TABLE_MAIN); 302 if (tb) 303 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF); 304 305 if (err == -EAGAIN) 306 err = -ENETUNREACH; 307 308 rcu_read_unlock(); 309 310 return err; 311 } 312 313 static inline bool fib4_rule_default(const struct fib_rule *rule) 314 { 315 return true; 316 } 317 318 static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb) 319 { 320 return 0; 321 } 322 323 static inline unsigned int fib4_rules_seq_read(struct net *net) 324 { 325 return 0; 326 } 327 328 static inline bool fib4_rules_early_flow_dissect(struct net *net, 329 struct sk_buff *skb, 330 struct flowi4 *fl4, 331 struct flow_keys *flkeys) 332 { 333 return false; 334 } 335 #else /* CONFIG_IP_MULTIPLE_TABLES */ 336 int __net_init fib4_rules_init(struct net *net); 337 void __net_exit fib4_rules_exit(struct net *net); 338 339 struct fib_table *fib_new_table(struct net *net, u32 id); 340 struct fib_table *fib_get_table(struct net *net, u32 id); 341 342 int __fib_lookup(struct net *net, struct flowi4 *flp, 343 struct fib_result *res, unsigned int flags); 344 345 static inline int fib_lookup(struct net *net, struct flowi4 *flp, 346 struct fib_result *res, unsigned int flags) 347 { 348 struct fib_table *tb; 349 int err = -ENETUNREACH; 350 351 flags |= FIB_LOOKUP_NOREF; 352 if (net->ipv4.fib_has_custom_rules) 353 return __fib_lookup(net, flp, res, flags); 354 355 rcu_read_lock(); 356 357 res->tclassid = 0; 358 359 tb = rcu_dereference_rtnl(net->ipv4.fib_main); 360 if (tb) 361 err = fib_table_lookup(tb, flp, res, flags); 362 363 if (!err) 364 goto out; 365 366 tb = rcu_dereference_rtnl(net->ipv4.fib_default); 367 if (tb) 368 err = fib_table_lookup(tb, flp, res, flags); 369 370 out: 371 if (err == -EAGAIN) 372 err = -ENETUNREACH; 373 374 rcu_read_unlock(); 375 376 return err; 377 } 378 379 bool fib4_rule_default(const struct fib_rule *rule); 380 int fib4_rules_dump(struct net *net, struct notifier_block *nb); 381 unsigned int fib4_rules_seq_read(struct net *net); 382 383 static inline bool fib4_rules_early_flow_dissect(struct net *net, 384 struct sk_buff *skb, 385 struct flowi4 *fl4, 386 struct flow_keys *flkeys) 387 { 388 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 389 390 if (!net->ipv4.fib_rules_require_fldissect) 391 return false; 392 393 skb_flow_dissect_flow_keys(skb, flkeys, flag); 394 fl4->fl4_sport = flkeys->ports.src; 395 fl4->fl4_dport = flkeys->ports.dst; 396 fl4->flowi4_proto = flkeys->basic.ip_proto; 397 398 return true; 399 } 400 401 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 402 403 /* Exported by fib_frontend.c */ 404 extern const struct nla_policy rtm_ipv4_policy[]; 405 void ip_fib_init(void); 406 int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla, 407 struct netlink_ext_ack *extack); 408 __be32 fib_compute_spec_dst(struct sk_buff *skb); 409 bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev); 410 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 411 u8 tos, int oif, struct net_device *dev, 412 struct in_device *idev, u32 *itag); 413 #ifdef CONFIG_IP_ROUTE_CLASSID 414 static inline int fib_num_tclassid_users(struct net *net) 415 { 416 return net->ipv4.fib_num_tclassid_users; 417 } 418 #else 419 static inline int fib_num_tclassid_users(struct net *net) 420 { 421 return 0; 422 } 423 #endif 424 int fib_unmerge(struct net *net); 425 426 /* Exported by fib_semantics.c */ 427 int ip_fib_check_default(__be32 gw, struct net_device *dev); 428 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force); 429 int fib_sync_down_addr(struct net_device *dev, __be32 local); 430 int fib_sync_up(struct net_device *dev, unsigned char nh_flags); 431 void fib_sync_mtu(struct net_device *dev, u32 orig_mtu); 432 433 #ifdef CONFIG_IP_ROUTE_MULTIPATH 434 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 435 const struct sk_buff *skb, struct flow_keys *flkeys); 436 #endif 437 void fib_select_multipath(struct fib_result *res, int hash); 438 void fib_select_path(struct net *net, struct fib_result *res, 439 struct flowi4 *fl4, const struct sk_buff *skb); 440 441 int fib_nh_init(struct net *net, struct fib_nh *fib_nh, 442 struct fib_config *cfg, int nh_weight, 443 struct netlink_ext_ack *extack); 444 void fib_nh_release(struct net *net, struct fib_nh *fib_nh); 445 int fib_nh_common_init(struct fib_nh_common *nhc, struct nlattr *fc_encap, 446 u16 fc_encap_type, void *cfg, gfp_t gfp_flags, 447 struct netlink_ext_ack *extack); 448 void fib_nh_common_release(struct fib_nh_common *nhc); 449 450 /* Exported by fib_trie.c */ 451 void fib_trie_init(void); 452 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias); 453 454 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 455 { 456 #ifdef CONFIG_IP_ROUTE_CLASSID 457 struct fib_nh_common *nhc = res->nhc; 458 struct fib_nh *nh = container_of(nhc, struct fib_nh, nh_common); 459 #ifdef CONFIG_IP_MULTIPLE_TABLES 460 u32 rtag; 461 #endif 462 *itag = nh->nh_tclassid << 16; 463 #ifdef CONFIG_IP_MULTIPLE_TABLES 464 rtag = res->tclassid; 465 if (*itag == 0) 466 *itag = (rtag<<16); 467 *itag |= (rtag>>16); 468 #endif 469 #endif 470 } 471 472 void free_fib_info(struct fib_info *fi); 473 474 static inline void fib_info_hold(struct fib_info *fi) 475 { 476 refcount_inc(&fi->fib_clntref); 477 } 478 479 static inline void fib_info_put(struct fib_info *fi) 480 { 481 if (refcount_dec_and_test(&fi->fib_clntref)) 482 free_fib_info(fi); 483 } 484 485 #ifdef CONFIG_PROC_FS 486 int __net_init fib_proc_init(struct net *net); 487 void __net_exit fib_proc_exit(struct net *net); 488 #else 489 static inline int fib_proc_init(struct net *net) 490 { 491 return 0; 492 } 493 static inline void fib_proc_exit(struct net *net) 494 { 495 } 496 #endif 497 498 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr); 499 500 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 501 struct fib_dump_filter *filter, 502 struct netlink_callback *cb); 503 504 int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nh, 505 unsigned char *flags, bool skip_oif); 506 int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nh, 507 int nh_weight); 508 #endif /* _NET_FIB_H */ 509