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 refcount_t 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 offload_failed:1, 217 unused:5; 218 }; 219 220 struct fib_entry_notifier_info { 221 struct fib_notifier_info info; /* must be first */ 222 u32 dst; 223 int dst_len; 224 struct fib_info *fi; 225 u8 tos; 226 u8 type; 227 u32 tb_id; 228 }; 229 230 struct fib_nh_notifier_info { 231 struct fib_notifier_info info; /* must be first */ 232 struct fib_nh *fib_nh; 233 }; 234 235 int call_fib4_notifier(struct notifier_block *nb, 236 enum fib_event_type event_type, 237 struct fib_notifier_info *info); 238 int call_fib4_notifiers(struct net *net, enum fib_event_type event_type, 239 struct fib_notifier_info *info); 240 241 int __net_init fib4_notifier_init(struct net *net); 242 void __net_exit fib4_notifier_exit(struct net *net); 243 244 void fib_info_notify_update(struct net *net, struct nl_info *info); 245 int fib_notify(struct net *net, struct notifier_block *nb, 246 struct netlink_ext_ack *extack); 247 248 struct fib_table { 249 struct hlist_node tb_hlist; 250 u32 tb_id; 251 int tb_num_default; 252 struct rcu_head rcu; 253 unsigned long *tb_data; 254 unsigned long __data[]; 255 }; 256 257 struct fib_dump_filter { 258 u32 table_id; 259 /* filter_set is an optimization that an entry is set */ 260 bool filter_set; 261 bool dump_routes; 262 bool dump_exceptions; 263 unsigned char protocol; 264 unsigned char rt_type; 265 unsigned int flags; 266 struct net_device *dev; 267 }; 268 269 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 270 struct fib_result *res, int fib_flags); 271 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *, 272 struct netlink_ext_ack *extack); 273 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *, 274 struct netlink_ext_ack *extack); 275 int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 276 struct netlink_callback *cb, struct fib_dump_filter *filter); 277 int fib_table_flush(struct net *net, struct fib_table *table, bool flush_all); 278 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb); 279 void fib_table_flush_external(struct fib_table *table); 280 void fib_free_table(struct fib_table *tb); 281 282 #ifndef CONFIG_IP_MULTIPLE_TABLES 283 284 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1)) 285 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1)) 286 287 static inline struct fib_table *fib_get_table(struct net *net, u32 id) 288 { 289 struct hlist_node *tb_hlist; 290 struct hlist_head *ptr; 291 292 ptr = id == RT_TABLE_LOCAL ? 293 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] : 294 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX]; 295 296 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr)); 297 298 return hlist_entry(tb_hlist, struct fib_table, tb_hlist); 299 } 300 301 static inline struct fib_table *fib_new_table(struct net *net, u32 id) 302 { 303 return fib_get_table(net, id); 304 } 305 306 static inline int fib_lookup(struct net *net, const struct flowi4 *flp, 307 struct fib_result *res, unsigned int flags) 308 { 309 struct fib_table *tb; 310 int err = -ENETUNREACH; 311 312 rcu_read_lock(); 313 314 tb = fib_get_table(net, RT_TABLE_MAIN); 315 if (tb) 316 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF); 317 318 if (err == -EAGAIN) 319 err = -ENETUNREACH; 320 321 rcu_read_unlock(); 322 323 return err; 324 } 325 326 static inline bool fib4_has_custom_rules(const struct net *net) 327 { 328 return false; 329 } 330 331 static inline bool fib4_rule_default(const struct fib_rule *rule) 332 { 333 return true; 334 } 335 336 static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb, 337 struct netlink_ext_ack *extack) 338 { 339 return 0; 340 } 341 342 static inline unsigned int fib4_rules_seq_read(struct net *net) 343 { 344 return 0; 345 } 346 347 static inline bool fib4_rules_early_flow_dissect(struct net *net, 348 struct sk_buff *skb, 349 struct flowi4 *fl4, 350 struct flow_keys *flkeys) 351 { 352 return false; 353 } 354 #else /* CONFIG_IP_MULTIPLE_TABLES */ 355 int __net_init fib4_rules_init(struct net *net); 356 void __net_exit fib4_rules_exit(struct net *net); 357 358 struct fib_table *fib_new_table(struct net *net, u32 id); 359 struct fib_table *fib_get_table(struct net *net, u32 id); 360 361 int __fib_lookup(struct net *net, struct flowi4 *flp, 362 struct fib_result *res, unsigned int flags); 363 364 static inline int fib_lookup(struct net *net, struct flowi4 *flp, 365 struct fib_result *res, unsigned int flags) 366 { 367 struct fib_table *tb; 368 int err = -ENETUNREACH; 369 370 flags |= FIB_LOOKUP_NOREF; 371 if (net->ipv4.fib_has_custom_rules) 372 return __fib_lookup(net, flp, res, flags); 373 374 rcu_read_lock(); 375 376 res->tclassid = 0; 377 378 tb = rcu_dereference_rtnl(net->ipv4.fib_main); 379 if (tb) 380 err = fib_table_lookup(tb, flp, res, flags); 381 382 if (!err) 383 goto out; 384 385 tb = rcu_dereference_rtnl(net->ipv4.fib_default); 386 if (tb) 387 err = fib_table_lookup(tb, flp, res, flags); 388 389 out: 390 if (err == -EAGAIN) 391 err = -ENETUNREACH; 392 393 rcu_read_unlock(); 394 395 return err; 396 } 397 398 static inline bool fib4_has_custom_rules(const struct net *net) 399 { 400 return net->ipv4.fib_has_custom_rules; 401 } 402 403 bool fib4_rule_default(const struct fib_rule *rule); 404 int fib4_rules_dump(struct net *net, struct notifier_block *nb, 405 struct netlink_ext_ack *extack); 406 unsigned int fib4_rules_seq_read(struct net *net); 407 408 static inline bool fib4_rules_early_flow_dissect(struct net *net, 409 struct sk_buff *skb, 410 struct flowi4 *fl4, 411 struct flow_keys *flkeys) 412 { 413 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; 414 415 if (!net->ipv4.fib_rules_require_fldissect) 416 return false; 417 418 skb_flow_dissect_flow_keys(skb, flkeys, flag); 419 fl4->fl4_sport = flkeys->ports.src; 420 fl4->fl4_dport = flkeys->ports.dst; 421 fl4->flowi4_proto = flkeys->basic.ip_proto; 422 423 return true; 424 } 425 426 #endif /* CONFIG_IP_MULTIPLE_TABLES */ 427 428 /* Exported by fib_frontend.c */ 429 extern const struct nla_policy rtm_ipv4_policy[]; 430 void ip_fib_init(void); 431 int fib_gw_from_via(struct fib_config *cfg, struct nlattr *nla, 432 struct netlink_ext_ack *extack); 433 __be32 fib_compute_spec_dst(struct sk_buff *skb); 434 bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev); 435 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, 436 u8 tos, int oif, struct net_device *dev, 437 struct in_device *idev, u32 *itag); 438 #ifdef CONFIG_IP_ROUTE_CLASSID 439 static inline int fib_num_tclassid_users(struct net *net) 440 { 441 return atomic_read(&net->ipv4.fib_num_tclassid_users); 442 } 443 #else 444 static inline int fib_num_tclassid_users(struct net *net) 445 { 446 return 0; 447 } 448 #endif 449 int fib_unmerge(struct net *net); 450 451 static inline bool nhc_l3mdev_matches_dev(const struct fib_nh_common *nhc, 452 const struct net_device *dev) 453 { 454 if (nhc->nhc_dev == dev || 455 l3mdev_master_ifindex_rcu(nhc->nhc_dev) == dev->ifindex) 456 return true; 457 458 return false; 459 } 460 461 /* Exported by fib_semantics.c */ 462 int ip_fib_check_default(__be32 gw, struct net_device *dev); 463 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force); 464 int fib_sync_down_addr(struct net_device *dev, __be32 local); 465 int fib_sync_up(struct net_device *dev, unsigned char nh_flags); 466 void fib_sync_mtu(struct net_device *dev, u32 orig_mtu); 467 void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig); 468 469 /* Fields used for sysctl_fib_multipath_hash_fields. 470 * Common to IPv4 and IPv6. 471 * 472 * Add new fields at the end. This is user API. 473 */ 474 #define FIB_MULTIPATH_HASH_FIELD_SRC_IP BIT(0) 475 #define FIB_MULTIPATH_HASH_FIELD_DST_IP BIT(1) 476 #define FIB_MULTIPATH_HASH_FIELD_IP_PROTO BIT(2) 477 #define FIB_MULTIPATH_HASH_FIELD_FLOWLABEL BIT(3) 478 #define FIB_MULTIPATH_HASH_FIELD_SRC_PORT BIT(4) 479 #define FIB_MULTIPATH_HASH_FIELD_DST_PORT BIT(5) 480 #define FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP BIT(6) 481 #define FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP BIT(7) 482 #define FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO BIT(8) 483 #define FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL BIT(9) 484 #define FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT BIT(10) 485 #define FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT BIT(11) 486 487 #define FIB_MULTIPATH_HASH_FIELD_OUTER_MASK \ 488 (FIB_MULTIPATH_HASH_FIELD_SRC_IP | \ 489 FIB_MULTIPATH_HASH_FIELD_DST_IP | \ 490 FIB_MULTIPATH_HASH_FIELD_IP_PROTO | \ 491 FIB_MULTIPATH_HASH_FIELD_FLOWLABEL | \ 492 FIB_MULTIPATH_HASH_FIELD_SRC_PORT | \ 493 FIB_MULTIPATH_HASH_FIELD_DST_PORT) 494 495 #define FIB_MULTIPATH_HASH_FIELD_INNER_MASK \ 496 (FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP | \ 497 FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP | \ 498 FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO | \ 499 FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL | \ 500 FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT | \ 501 FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) 502 503 #define FIB_MULTIPATH_HASH_FIELD_ALL_MASK \ 504 (FIB_MULTIPATH_HASH_FIELD_OUTER_MASK | \ 505 FIB_MULTIPATH_HASH_FIELD_INNER_MASK) 506 507 #define FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK \ 508 (FIB_MULTIPATH_HASH_FIELD_SRC_IP | \ 509 FIB_MULTIPATH_HASH_FIELD_DST_IP | \ 510 FIB_MULTIPATH_HASH_FIELD_IP_PROTO) 511 512 #ifdef CONFIG_IP_ROUTE_MULTIPATH 513 int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 514 const struct sk_buff *skb, struct flow_keys *flkeys); 515 #endif 516 int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope, 517 struct netlink_ext_ack *extack); 518 void fib_select_multipath(struct fib_result *res, int hash); 519 void fib_select_path(struct net *net, struct fib_result *res, 520 struct flowi4 *fl4, const struct sk_buff *skb); 521 522 int fib_nh_init(struct net *net, struct fib_nh *fib_nh, 523 struct fib_config *cfg, int nh_weight, 524 struct netlink_ext_ack *extack); 525 void fib_nh_release(struct net *net, struct fib_nh *fib_nh); 526 int fib_nh_common_init(struct net *net, struct fib_nh_common *nhc, 527 struct nlattr *fc_encap, u16 fc_encap_type, 528 void *cfg, gfp_t gfp_flags, 529 struct netlink_ext_ack *extack); 530 void fib_nh_common_release(struct fib_nh_common *nhc); 531 532 /* Exported by fib_trie.c */ 533 void fib_alias_hw_flags_set(struct net *net, const struct fib_rt_info *fri); 534 void fib_trie_init(void); 535 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias); 536 bool fib_lookup_good_nhc(const struct fib_nh_common *nhc, int fib_flags, 537 const struct flowi4 *flp); 538 539 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 540 { 541 #ifdef CONFIG_IP_ROUTE_CLASSID 542 struct fib_nh_common *nhc = res->nhc; 543 #ifdef CONFIG_IP_MULTIPLE_TABLES 544 u32 rtag; 545 #endif 546 if (nhc->nhc_family == AF_INET) { 547 struct fib_nh *nh; 548 549 nh = container_of(nhc, struct fib_nh, nh_common); 550 *itag = nh->nh_tclassid << 16; 551 } else { 552 *itag = 0; 553 } 554 555 #ifdef CONFIG_IP_MULTIPLE_TABLES 556 rtag = res->tclassid; 557 if (*itag == 0) 558 *itag = (rtag<<16); 559 *itag |= (rtag>>16); 560 #endif 561 #endif 562 } 563 564 void fib_flush(struct net *net); 565 void free_fib_info(struct fib_info *fi); 566 567 static inline void fib_info_hold(struct fib_info *fi) 568 { 569 refcount_inc(&fi->fib_clntref); 570 } 571 572 static inline void fib_info_put(struct fib_info *fi) 573 { 574 if (refcount_dec_and_test(&fi->fib_clntref)) 575 free_fib_info(fi); 576 } 577 578 #ifdef CONFIG_PROC_FS 579 int __net_init fib_proc_init(struct net *net); 580 void __net_exit fib_proc_exit(struct net *net); 581 #else 582 static inline int fib_proc_init(struct net *net) 583 { 584 return 0; 585 } 586 static inline void fib_proc_exit(struct net *net) 587 { 588 } 589 #endif 590 591 u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr); 592 593 int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 594 struct fib_dump_filter *filter, 595 struct netlink_callback *cb); 596 597 int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nh, 598 u8 rt_family, unsigned char *flags, bool skip_oif); 599 int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nh, 600 int nh_weight, u8 rt_family, u32 nh_tclassid); 601 #endif /* _NET_FIB_H */ 602