1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * Definitions for the Forwarding Information Base. 8 * 9 * Authors: A.N.Kuznetsov, <kuznet@ms2.inr.ac.ru> 10 */ 11 12 #ifndef _NET_IP_FIB_H 13 #define _NET_IP_FIB_H 14 15 #include <net/flow.h> 16 #include <linux/seq_file.h> 17 #include <linux/rcupdate.h> 18 #include <net/fib_notifier.h> 19 #include <net/fib_rules.h> 20 #include <net/inetpeer.h> 21 #include <linux/percpu.h> 22 #include <linux/notifier.h> 23 #include <linux/refcount.h> 24 25 struct fib_config { 26 u8 fc_dst_len; 27 u8 fc_tos; 28 u8 fc_protocol; 29 u8 fc_scope; 30 u8 fc_type; 31 u8 fc_gw_family; 32 /* 2 bytes unused */ 33 u32 fc_table; 34 __be32 fc_dst; 35 union { 36 __be32 fc_gw4; 37 struct in6_addr fc_gw6; 38 }; 39 int fc_oif; 40 u32 fc_flags; 41 u32 fc_priority; 42 __be32 fc_prefsrc; 43 u32 fc_nh_id; 44 struct nlattr *fc_mx; 45 struct rtnexthop *fc_mp; 46 int fc_mx_len; 47 int fc_mp_len; 48 u32 fc_flow; 49 u32 fc_nlflags; 50 struct nl_info fc_nlinfo; 51 struct nlattr *fc_encap; 52 u16 fc_encap_type; 53 }; 54 55 struct fib_info; 56 struct rtable; 57 58 struct fib_nh_exception { 59 struct fib_nh_exception __rcu *fnhe_next; 60 int fnhe_genid; 61 __be32 fnhe_daddr; 62 u32 fnhe_pmtu; 63 bool fnhe_mtu_locked; 64 __be32 fnhe_gw; 65 unsigned long fnhe_expires; 66 struct rtable __rcu *fnhe_rth_input; 67 struct rtable __rcu *fnhe_rth_output; 68 unsigned long fnhe_stamp; 69 struct rcu_head rcu; 70 }; 71 72 struct fnhe_hash_bucket { 73 struct fib_nh_exception __rcu *chain; 74 }; 75 76 #define FNHE_HASH_SHIFT 11 77 #define FNHE_HASH_SIZE (1 << FNHE_HASH_SHIFT) 78 #define FNHE_RECLAIM_DEPTH 5 79 80 struct fib_nh_common { 81 struct net_device *nhc_dev; 82 int nhc_oif; 83 unsigned char nhc_scope; 84 u8 nhc_family; 85 u8 nhc_gw_family; 86 unsigned char nhc_flags; 87 struct lwtunnel_state *nhc_lwtstate; 88 89 union { 90 __be32 ipv4; 91 struct in6_addr ipv6; 92 } nhc_gw; 93 94 int nhc_weight; 95 atomic_t nhc_upper_bound; 96 97 /* v4 specific, but allows fib6_nh with v4 routes */ 98 struct rtable __rcu * __percpu *nhc_pcpu_rth_output; 99 struct rtable __rcu *nhc_rth_input; 100 struct fnhe_hash_bucket __rcu *nhc_exceptions; 101 }; 102 103 struct fib_nh { 104 struct fib_nh_common nh_common; 105 struct hlist_node nh_hash; 106 struct fib_info *nh_parent; 107 #ifdef CONFIG_IP_ROUTE_CLASSID 108 __u32 nh_tclassid; 109 #endif 110 __be32 nh_saddr; 111 int nh_saddr_genid; 112 #define fib_nh_family nh_common.nhc_family 113 #define fib_nh_dev nh_common.nhc_dev 114 #define fib_nh_oif nh_common.nhc_oif 115 #define fib_nh_flags nh_common.nhc_flags 116 #define fib_nh_lws nh_common.nhc_lwtstate 117 #define fib_nh_scope nh_common.nhc_scope 118 #define fib_nh_gw_family nh_common.nhc_gw_family 119 #define fib_nh_gw4 nh_common.nhc_gw.ipv4 120 #define fib_nh_gw6 nh_common.nhc_gw.ipv6 121 #define fib_nh_weight nh_common.nhc_weight 122 #define fib_nh_upper_bound nh_common.nhc_upper_bound 123 }; 124 125 /* 126 * This structure contains data shared by many of routes. 127 */ 128 129 struct nexthop; 130 131 struct fib_info { 132 struct hlist_node fib_hash; 133 struct hlist_node fib_lhash; 134 struct list_head nh_list; 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 nexthop *nh; 155 struct rcu_head rcu; 156 struct fib_nh fib_nh[0]; 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 #ifdef CONFIG_IP_MULTIPLE_TABLES 194 #define FIB_TABLE_HASHSZ 256 195 #else 196 #define FIB_TABLE_HASHSZ 2 197 #endif 198 199 __be32 fib_info_update_nhc_saddr(struct net *net, struct fib_nh_common *nhc, 200 unsigned char scope); 201 __be32 fib_result_prefsrc(struct net *net, struct fib_result *res); 202 203 #define FIB_RES_NHC(res) ((res).nhc) 204 #define FIB_RES_DEV(res) (FIB_RES_NHC(res)->nhc_dev) 205 #define FIB_RES_OIF(res) (FIB_RES_NHC(res)->nhc_oif) 206 207 struct fib_entry_notifier_info { 208 struct fib_notifier_info info; /* must be first */ 209 u32 dst; 210 int dst_len; 211 struct fib_info *fi; 212 u8 tos; 213 u8 type; 214 u32 tb_id; 215 }; 216 217 struct fib_nh_notifier_info { 218 struct fib_notifier_info info; /* must be first */ 219 struct fib_nh *fib_nh; 220 }; 221 222 int call_fib4_notifier(struct notifier_block *nb, 223 enum fib_event_type event_type, 224 struct fib_notifier_info *info); 225 int call_fib4_notifiers(struct net *net, enum fib_event_type event_type, 226 struct fib_notifier_info *info); 227 228 int __net_init fib4_notifier_init(struct net *net); 229 void __net_exit fib4_notifier_exit(struct net *net); 230 231 void fib_info_notify_update(struct net *net, struct nl_info *info); 232 int fib_notify(struct net *net, struct notifier_block *nb, 233 struct netlink_ext_ack *extack); 234 235 struct fib_table { 236 struct hlist_node tb_hlist; 237 u32 tb_id; 238 int tb_num_default; 239 struct rcu_head rcu; 240 unsigned long *tb_data; 241 unsigned long __data[0]; 242 }; 243 244 struct fib_dump_filter { 245 u32 table_id; 246 /* filter_set is an optimization that an entry is set */ 247 bool filter_set; 248 bool dump_all_families; 249 bool dump_routes; 250 bool dump_exceptions; 251 unsigned char protocol; 252 unsigned char rt_type; 253 unsigned int flags; 254 struct net_device *dev; 255 }; 256 257 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 258 struct fib_result *res, int fib_flags); 259 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *, 260 struct netlink_ext_ack *extack); 261 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *, 262 struct netlink_ext_ack *extack); 263 int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 264 struct netlink_callback *cb, struct fib_dump_filter *filter); 265 int fib_table_flush(struct net *net, struct fib_table *table, bool flush_all); 266 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb); 267 void fib_table_flush_external(struct fib_table *table); 268 void fib_free_table(struct fib_table *tb); 269 270 #ifndef CONFIG_IP_MULTIPLE_TABLES 271 272 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1)) 273 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1)) 274 275 static inline struct fib_table *fib_get_table(struct net *net, u32 id) 276 { 277 struct hlist_node *tb_hlist; 278 struct hlist_head *ptr; 279 280 ptr = id == RT_TABLE_LOCAL ? 281 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] : 282 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]; 283 284 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr)); 285 286 return hlist_entry(tb_hlist, struct fib_table, tb_hlist); 287 } 288 289 static inline struct fib_table *fib_new_table(struct net *net, u32 id) 290 { 291 return fib_get_table(net, id); 292 } 293 294 static inline int fib_lookup(struct net *net, const struct flowi4 *flp, 295 struct fib_result *res, unsigned int flags) 296 { 297 struct fib_table *tb; 298 int err = -ENETUNREACH; 299 300 rcu_read_lock(); 301 302 tb = fib_get_table(net, RT_TABLE_MAIN); 303 if (tb) 304 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF); 305 306 if (err == -EAGAIN) 307 err = -ENETUNREACH; 308 309 rcu_read_unlock(); 310 311 return err; 312 } 313 314 static inline bool fib4_has_custom_rules(const struct net *net) 315 { 316 return false; 317 } 318 319 static inline bool fib4_rule_default(const struct fib_rule *rule) 320 { 321 return true; 322 } 323 324 static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb, 325 struct netlink_ext_ack *extack) 326 { 327 return 0; 328 } 329 330 static inline unsigned int fib4_rules_seq_read(struct net *net) 331 { 332 return 0; 333 } 334 335 static inline bool fib4_rules_early_flow_dissect(struct net *net, 336 struct sk_buff *skb, 337 struct flowi4 *fl4, 338 struct flow_keys *flkeys) 339 { 340 return false; 341 } 342 #else /* CONFIG_IP_MULTIPLE_TABLES */ 343 int __net_init fib4_rules_init(struct net *net); 344 void __net_exit fib4_rules_exit(struct net *net); 345 346 struct fib_table *fib_new_table(struct net *net, u32 id); 347 struct fib_table *fib_get_table(struct net *net, u32 id); 348 349 int __fib_lookup(struct net *net, struct flowi4 *flp, 350 struct fib_result *res, unsigned int flags); 351 352 static inline int fib_lookup(struct net *net, struct flowi4 *flp, 353 struct fib_result *res, unsigned int flags) 354 { 355 struct fib_table *tb; 356 int err = -ENETUNREACH; 357 358 flags |= FIB_LOOKUP_NOREF; 359 if (net->ipv4.fib_has_custom_rules) 360 return __fib_lookup(net, flp, res, flags); 361 362 rcu_read_lock(); 363 364 res->tclassid = 0; 365 366 tb = rcu_dereference_rtnl(net->ipv4.fib_main); 367 if (tb) 368 err = fib_table_lookup(tb, flp, res, flags); 369 370 if (!err) 371 goto out; 372 373 tb = rcu_dereference_rtnl(net->ipv4.fib_default); 374 if (tb) 375 err = fib_table_lookup(tb, flp, res, flags); 376 377 out: 378 if (err == -EAGAIN) 379 err = -ENETUNREACH; 380 381 rcu_read_unlock(); 382 383 return err; 384 } 385 386 static inline bool fib4_has_custom_rules(const struct net *net) 387 { 388 return net->ipv4.fib_has_custom_rules; 389 } 390 391 bool fib4_rule_default(const struct fib_rule *rule); 392 int fib4_rules_dump(struct net *net, struct notifier_block *nb, 393 struct netlink_ext_ack *extack); 394 unsigned int fib4_rules_seq_read(struct net *net); 395 396 static inline bool fib4_rules_early_flow_dissect(struct net *net, 397 struct sk_buff *skb, 398 struct flowi4 *fl4, 399 struct flow_keys *flkeys) 400 { 401 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 402 403 if (!net->ipv4.fib_rules_require_fldissect) 404 return false; 405 406 skb_flow_dissect_flow_keys(skb, flkeys, flag); 407 fl4->fl4_sport = flkeys->ports.src; 408 fl4->fl4_dport = flkeys->ports.dst; 409 fl4->flowi4_proto = flkeys->basic.ip_proto; 410 411 return true; 412 } 413 414 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 415 416 /* Exported by fib_frontend.c */ 417 extern const struct nla_policy rtm_ipv4_policy[]; 418 void ip_fib_init(void); 419 int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla, 420 struct netlink_ext_ack *extack); 421 __be32 fib_compute_spec_dst(struct sk_buff *skb); 422 bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev); 423 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 424 u8 tos, int oif, struct net_device *dev, 425 struct in_device *idev, u32 *itag); 426 #ifdef CONFIG_IP_ROUTE_CLASSID 427 static inline int fib_num_tclassid_users(struct net *net) 428 { 429 return net->ipv4.fib_num_tclassid_users; 430 } 431 #else 432 static inline int fib_num_tclassid_users(struct net *net) 433 { 434 return 0; 435 } 436 #endif 437 int fib_unmerge(struct net *net); 438 439 /* Exported by fib_semantics.c */ 440 int ip_fib_check_default(__be32 gw, struct net_device *dev); 441 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force); 442 int fib_sync_down_addr(struct net_device *dev, __be32 local); 443 int fib_sync_up(struct net_device *dev, unsigned char nh_flags); 444 void fib_sync_mtu(struct net_device *dev, u32 orig_mtu); 445 void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig); 446 447 #ifdef CONFIG_IP_ROUTE_MULTIPATH 448 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 449 const struct sk_buff *skb, struct flow_keys *flkeys); 450 #endif 451 int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope, 452 struct netlink_ext_ack *extack); 453 void fib_select_multipath(struct fib_result *res, int hash); 454 void fib_select_path(struct net *net, struct fib_result *res, 455 struct flowi4 *fl4, const struct sk_buff *skb); 456 457 int fib_nh_init(struct net *net, struct fib_nh *fib_nh, 458 struct fib_config *cfg, int nh_weight, 459 struct netlink_ext_ack *extack); 460 void fib_nh_release(struct net *net, struct fib_nh *fib_nh); 461 int fib_nh_common_init(struct fib_nh_common *nhc, struct nlattr *fc_encap, 462 u16 fc_encap_type, void *cfg, gfp_t gfp_flags, 463 struct netlink_ext_ack *extack); 464 void fib_nh_common_release(struct fib_nh_common *nhc); 465 466 /* Exported by fib_trie.c */ 467 void fib_trie_init(void); 468 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias); 469 470 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 471 { 472 #ifdef CONFIG_IP_ROUTE_CLASSID 473 struct fib_nh_common *nhc = res->nhc; 474 #ifdef CONFIG_IP_MULTIPLE_TABLES 475 u32 rtag; 476 #endif 477 if (nhc->nhc_family == AF_INET) { 478 struct fib_nh *nh; 479 480 nh = container_of(nhc, struct fib_nh, nh_common); 481 *itag = nh->nh_tclassid << 16; 482 } else { 483 *itag = 0; 484 } 485 486 #ifdef CONFIG_IP_MULTIPLE_TABLES 487 rtag = res->tclassid; 488 if (*itag == 0) 489 *itag = (rtag<<16); 490 *itag |= (rtag>>16); 491 #endif 492 #endif 493 } 494 495 void fib_flush(struct net *net); 496 void free_fib_info(struct fib_info *fi); 497 498 static inline void fib_info_hold(struct fib_info *fi) 499 { 500 refcount_inc(&fi->fib_clntref); 501 } 502 503 static inline void fib_info_put(struct fib_info *fi) 504 { 505 if (refcount_dec_and_test(&fi->fib_clntref)) 506 free_fib_info(fi); 507 } 508 509 #ifdef CONFIG_PROC_FS 510 int __net_init fib_proc_init(struct net *net); 511 void __net_exit fib_proc_exit(struct net *net); 512 #else 513 static inline int fib_proc_init(struct net *net) 514 { 515 return 0; 516 } 517 static inline void fib_proc_exit(struct net *net) 518 { 519 } 520 #endif 521 522 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr); 523 524 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 525 struct fib_dump_filter *filter, 526 struct netlink_callback *cb); 527 528 int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nh, 529 u8 rt_family, unsigned char *flags, bool skip_oif); 530 int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nh, 531 int nh_weight, u8 rt_family); 532 #endif /* _NET_FIB_H */ 533