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[]; 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_rt_info { 208 struct fib_info *fi; 209 u32 tb_id; 210 __be32 dst; 211 int dst_len; 212 u8 tos; 213 u8 type; 214 u8 offload:1, 215 trap:1, 216 unused:6; 217 }; 218 219 struct fib_entry_notifier_info { 220 struct fib_notifier_info info; /* must be first */ 221 u32 dst; 222 int dst_len; 223 struct fib_info *fi; 224 u8 tos; 225 u8 type; 226 u32 tb_id; 227 }; 228 229 struct fib_nh_notifier_info { 230 struct fib_notifier_info info; /* must be first */ 231 struct fib_nh *fib_nh; 232 }; 233 234 int call_fib4_notifier(struct notifier_block *nb, 235 enum fib_event_type event_type, 236 struct fib_notifier_info *info); 237 int call_fib4_notifiers(struct net *net, enum fib_event_type event_type, 238 struct fib_notifier_info *info); 239 240 int __net_init fib4_notifier_init(struct net *net); 241 void __net_exit fib4_notifier_exit(struct net *net); 242 243 void fib_info_notify_update(struct net *net, struct nl_info *info); 244 int fib_notify(struct net *net, struct notifier_block *nb, 245 struct netlink_ext_ack *extack); 246 247 struct fib_table { 248 struct hlist_node tb_hlist; 249 u32 tb_id; 250 int tb_num_default; 251 struct rcu_head rcu; 252 unsigned long *tb_data; 253 unsigned long __data[]; 254 }; 255 256 struct fib_dump_filter { 257 u32 table_id; 258 /* filter_set is an optimization that an entry is set */ 259 bool filter_set; 260 bool dump_routes; 261 bool dump_exceptions; 262 unsigned char protocol; 263 unsigned char rt_type; 264 unsigned int flags; 265 struct net_device *dev; 266 }; 267 268 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 269 struct fib_result *res, int fib_flags); 270 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *, 271 struct netlink_ext_ack *extack); 272 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *, 273 struct netlink_ext_ack *extack); 274 int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 275 struct netlink_callback *cb, struct fib_dump_filter *filter); 276 int fib_table_flush(struct net *net, struct fib_table *table, bool flush_all); 277 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb); 278 void fib_table_flush_external(struct fib_table *table); 279 void fib_free_table(struct fib_table *tb); 280 281 #ifndef CONFIG_IP_MULTIPLE_TABLES 282 283 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1)) 284 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1)) 285 286 static inline struct fib_table *fib_get_table(struct net *net, u32 id) 287 { 288 struct hlist_node *tb_hlist; 289 struct hlist_head *ptr; 290 291 ptr = id == RT_TABLE_LOCAL ? 292 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] : 293 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]; 294 295 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr)); 296 297 return hlist_entry(tb_hlist, struct fib_table, tb_hlist); 298 } 299 300 static inline struct fib_table *fib_new_table(struct net *net, u32 id) 301 { 302 return fib_get_table(net, id); 303 } 304 305 static inline int fib_lookup(struct net *net, const struct flowi4 *flp, 306 struct fib_result *res, unsigned int flags) 307 { 308 struct fib_table *tb; 309 int err = -ENETUNREACH; 310 311 rcu_read_lock(); 312 313 tb = fib_get_table(net, RT_TABLE_MAIN); 314 if (tb) 315 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF); 316 317 if (err == -EAGAIN) 318 err = -ENETUNREACH; 319 320 rcu_read_unlock(); 321 322 return err; 323 } 324 325 static inline bool fib4_has_custom_rules(const struct net *net) 326 { 327 return false; 328 } 329 330 static inline bool fib4_rule_default(const struct fib_rule *rule) 331 { 332 return true; 333 } 334 335 static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb, 336 struct netlink_ext_ack *extack) 337 { 338 return 0; 339 } 340 341 static inline unsigned int fib4_rules_seq_read(struct net *net) 342 { 343 return 0; 344 } 345 346 static inline bool fib4_rules_early_flow_dissect(struct net *net, 347 struct sk_buff *skb, 348 struct flowi4 *fl4, 349 struct flow_keys *flkeys) 350 { 351 return false; 352 } 353 #else /* CONFIG_IP_MULTIPLE_TABLES */ 354 int __net_init fib4_rules_init(struct net *net); 355 void __net_exit fib4_rules_exit(struct net *net); 356 357 struct fib_table *fib_new_table(struct net *net, u32 id); 358 struct fib_table *fib_get_table(struct net *net, u32 id); 359 360 int __fib_lookup(struct net *net, struct flowi4 *flp, 361 struct fib_result *res, unsigned int flags); 362 363 static inline int fib_lookup(struct net *net, struct flowi4 *flp, 364 struct fib_result *res, unsigned int flags) 365 { 366 struct fib_table *tb; 367 int err = -ENETUNREACH; 368 369 flags |= FIB_LOOKUP_NOREF; 370 if (net->ipv4.fib_has_custom_rules) 371 return __fib_lookup(net, flp, res, flags); 372 373 rcu_read_lock(); 374 375 res->tclassid = 0; 376 377 tb = rcu_dereference_rtnl(net->ipv4.fib_main); 378 if (tb) 379 err = fib_table_lookup(tb, flp, res, flags); 380 381 if (!err) 382 goto out; 383 384 tb = rcu_dereference_rtnl(net->ipv4.fib_default); 385 if (tb) 386 err = fib_table_lookup(tb, flp, res, flags); 387 388 out: 389 if (err == -EAGAIN) 390 err = -ENETUNREACH; 391 392 rcu_read_unlock(); 393 394 return err; 395 } 396 397 static inline bool fib4_has_custom_rules(const struct net *net) 398 { 399 return net->ipv4.fib_has_custom_rules; 400 } 401 402 bool fib4_rule_default(const struct fib_rule *rule); 403 int fib4_rules_dump(struct net *net, struct notifier_block *nb, 404 struct netlink_ext_ack *extack); 405 unsigned int fib4_rules_seq_read(struct net *net); 406 407 static inline bool fib4_rules_early_flow_dissect(struct net *net, 408 struct sk_buff *skb, 409 struct flowi4 *fl4, 410 struct flow_keys *flkeys) 411 { 412 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 413 414 if (!net->ipv4.fib_rules_require_fldissect) 415 return false; 416 417 skb_flow_dissect_flow_keys(skb, flkeys, flag); 418 fl4->fl4_sport = flkeys->ports.src; 419 fl4->fl4_dport = flkeys->ports.dst; 420 fl4->flowi4_proto = flkeys->basic.ip_proto; 421 422 return true; 423 } 424 425 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 426 427 /* Exported by fib_frontend.c */ 428 extern const struct nla_policy rtm_ipv4_policy[]; 429 void ip_fib_init(void); 430 int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla, 431 struct netlink_ext_ack *extack); 432 __be32 fib_compute_spec_dst(struct sk_buff *skb); 433 bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev); 434 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 435 u8 tos, int oif, struct net_device *dev, 436 struct in_device *idev, u32 *itag); 437 #ifdef CONFIG_IP_ROUTE_CLASSID 438 static inline int fib_num_tclassid_users(struct net *net) 439 { 440 return net->ipv4.fib_num_tclassid_users; 441 } 442 #else 443 static inline int fib_num_tclassid_users(struct net *net) 444 { 445 return 0; 446 } 447 #endif 448 int fib_unmerge(struct net *net); 449 450 static inline bool nhc_l3mdev_matches_dev(const struct fib_nh_common *nhc, 451 const struct net_device *dev) 452 { 453 if (nhc->nhc_dev == dev || 454 l3mdev_master_ifindex_rcu(nhc->nhc_dev) == dev->ifindex) 455 return true; 456 457 return false; 458 } 459 460 /* Exported by fib_semantics.c */ 461 int ip_fib_check_default(__be32 gw, struct net_device *dev); 462 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force); 463 int fib_sync_down_addr(struct net_device *dev, __be32 local); 464 int fib_sync_up(struct net_device *dev, unsigned char nh_flags); 465 void fib_sync_mtu(struct net_device *dev, u32 orig_mtu); 466 void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig); 467 468 #ifdef CONFIG_IP_ROUTE_MULTIPATH 469 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 470 const struct sk_buff *skb, struct flow_keys *flkeys); 471 #endif 472 int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope, 473 struct netlink_ext_ack *extack); 474 void fib_select_multipath(struct fib_result *res, int hash); 475 void fib_select_path(struct net *net, struct fib_result *res, 476 struct flowi4 *fl4, const struct sk_buff *skb); 477 478 int fib_nh_init(struct net *net, struct fib_nh *fib_nh, 479 struct fib_config *cfg, int nh_weight, 480 struct netlink_ext_ack *extack); 481 void fib_nh_release(struct net *net, struct fib_nh *fib_nh); 482 int fib_nh_common_init(struct net *net, struct fib_nh_common *nhc, 483 struct nlattr *fc_encap, u16 fc_encap_type, 484 void *cfg, gfp_t gfp_flags, 485 struct netlink_ext_ack *extack); 486 void fib_nh_common_release(struct fib_nh_common *nhc); 487 488 /* Exported by fib_trie.c */ 489 void fib_alias_hw_flags_set(struct net *net, const struct fib_rt_info *fri); 490 void fib_trie_init(void); 491 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias); 492 bool fib_lookup_good_nhc(const struct fib_nh_common *nhc, int fib_flags, 493 const struct flowi4 *flp); 494 495 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 496 { 497 #ifdef CONFIG_IP_ROUTE_CLASSID 498 struct fib_nh_common *nhc = res->nhc; 499 #ifdef CONFIG_IP_MULTIPLE_TABLES 500 u32 rtag; 501 #endif 502 if (nhc->nhc_family == AF_INET) { 503 struct fib_nh *nh; 504 505 nh = container_of(nhc, struct fib_nh, nh_common); 506 *itag = nh->nh_tclassid << 16; 507 } else { 508 *itag = 0; 509 } 510 511 #ifdef CONFIG_IP_MULTIPLE_TABLES 512 rtag = res->tclassid; 513 if (*itag == 0) 514 *itag = (rtag<<16); 515 *itag |= (rtag>>16); 516 #endif 517 #endif 518 } 519 520 void fib_flush(struct net *net); 521 void free_fib_info(struct fib_info *fi); 522 523 static inline void fib_info_hold(struct fib_info *fi) 524 { 525 refcount_inc(&fi->fib_clntref); 526 } 527 528 static inline void fib_info_put(struct fib_info *fi) 529 { 530 if (refcount_dec_and_test(&fi->fib_clntref)) 531 free_fib_info(fi); 532 } 533 534 #ifdef CONFIG_PROC_FS 535 int __net_init fib_proc_init(struct net *net); 536 void __net_exit fib_proc_exit(struct net *net); 537 #else 538 static inline int fib_proc_init(struct net *net) 539 { 540 return 0; 541 } 542 static inline void fib_proc_exit(struct net *net) 543 { 544 } 545 #endif 546 547 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr); 548 549 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 550 struct fib_dump_filter *filter, 551 struct netlink_callback *cb); 552 553 int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nh, 554 u8 rt_family, unsigned char *flags, bool skip_oif); 555 int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nh, 556 int nh_weight, u8 rt_family); 557 #endif /* _NET_FIB_H */ 558