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, struct net *net, 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 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 bool dump_routes; 249 bool dump_exceptions; 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 void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig); 433 434 #ifdef CONFIG_IP_ROUTE_MULTIPATH 435 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 436 const struct sk_buff *skb, struct flow_keys *flkeys); 437 #endif 438 int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope, 439 struct netlink_ext_ack *extack); 440 void fib_select_multipath(struct fib_result *res, int hash); 441 void fib_select_path(struct net *net, struct fib_result *res, 442 struct flowi4 *fl4, const struct sk_buff *skb); 443 444 int fib_nh_init(struct net *net, struct fib_nh *fib_nh, 445 struct fib_config *cfg, int nh_weight, 446 struct netlink_ext_ack *extack); 447 void fib_nh_release(struct net *net, struct fib_nh *fib_nh); 448 int fib_nh_common_init(struct fib_nh_common *nhc, struct nlattr *fc_encap, 449 u16 fc_encap_type, void *cfg, gfp_t gfp_flags, 450 struct netlink_ext_ack *extack); 451 void fib_nh_common_release(struct fib_nh_common *nhc); 452 453 /* Exported by fib_trie.c */ 454 void fib_trie_init(void); 455 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias); 456 457 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 458 { 459 #ifdef CONFIG_IP_ROUTE_CLASSID 460 struct fib_nh_common *nhc = res->nhc; 461 #ifdef CONFIG_IP_MULTIPLE_TABLES 462 u32 rtag; 463 #endif 464 if (nhc->nhc_family == AF_INET) { 465 struct fib_nh *nh; 466 467 nh = container_of(nhc, struct fib_nh, nh_common); 468 *itag = nh->nh_tclassid << 16; 469 } else { 470 *itag = 0; 471 } 472 473 #ifdef CONFIG_IP_MULTIPLE_TABLES 474 rtag = res->tclassid; 475 if (*itag == 0) 476 *itag = (rtag<<16); 477 *itag |= (rtag>>16); 478 #endif 479 #endif 480 } 481 482 void fib_flush(struct net *net); 483 void free_fib_info(struct fib_info *fi); 484 485 static inline void fib_info_hold(struct fib_info *fi) 486 { 487 refcount_inc(&fi->fib_clntref); 488 } 489 490 static inline void fib_info_put(struct fib_info *fi) 491 { 492 if (refcount_dec_and_test(&fi->fib_clntref)) 493 free_fib_info(fi); 494 } 495 496 #ifdef CONFIG_PROC_FS 497 int __net_init fib_proc_init(struct net *net); 498 void __net_exit fib_proc_exit(struct net *net); 499 #else 500 static inline int fib_proc_init(struct net *net) 501 { 502 return 0; 503 } 504 static inline void fib_proc_exit(struct net *net) 505 { 506 } 507 #endif 508 509 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr); 510 511 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 512 struct fib_dump_filter *filter, 513 struct netlink_callback *cb); 514 515 int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nh, 516 u8 rt_family, unsigned char *flags, bool skip_oif); 517 int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nh, 518 int nh_weight, u8 rt_family); 519 #endif /* _NET_FIB_H */ 520