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 25struct 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 55struct fib_info; 56struct rtable; 57 58struct 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 72struct 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 80struct 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 103struct 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 129struct nexthop; 130 131struct 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 bool pfsrc_removed; 155 struct nexthop *nh; 156 struct rcu_head rcu; 157 struct fib_nh fib_nh[]; 158}; 159 160 161#ifdef CONFIG_IP_MULTIPLE_TABLES 162struct fib_rule; 163#endif 164 165struct fib_table; 166struct fib_result { 167 __be32 prefix; 168 unsigned char prefixlen; 169 unsigned char nh_sel; 170 unsigned char type; 171 unsigned char scope; 172 u32 tclassid; 173 struct fib_nh_common *nhc; 174 struct fib_info *fi; 175 struct fib_table *table; 176 struct hlist_head *fa_head; 177}; 178 179struct fib_result_nl { 180 __be32 fl_addr; /* To be looked up*/ 181 u32 fl_mark; 182 unsigned char fl_tos; 183 unsigned char fl_scope; 184 unsigned char tb_id_in; 185 186 unsigned char tb_id; /* Results */ 187 unsigned char prefixlen; 188 unsigned char nh_sel; 189 unsigned char type; 190 unsigned char scope; 191 int err; 192}; 193 194#ifdef CONFIG_IP_MULTIPLE_TABLES 195#define FIB_TABLE_HASHSZ 256 196#else 197#define FIB_TABLE_HASHSZ 2 198#endif 199 200__be32 fib_info_update_nhc_saddr(struct net *net, struct fib_nh_common *nhc, 201 unsigned char scope); 202__be32 fib_result_prefsrc(struct net *net, struct fib_result *res); 203 204#define FIB_RES_NHC(res) ((res).nhc) 205#define FIB_RES_DEV(res) (FIB_RES_NHC(res)->nhc_dev) 206#define FIB_RES_OIF(res) (FIB_RES_NHC(res)->nhc_oif) 207 208struct fib_rt_info { 209 struct fib_info *fi; 210 u32 tb_id; 211 __be32 dst; 212 int dst_len; 213 u8 tos; 214 u8 type; 215 u8 offload:1, 216 trap:1, 217 unused:6; 218}; 219 220struct 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 230struct fib_nh_notifier_info { 231 struct fib_notifier_info info; /* must be first */ 232 struct fib_nh *fib_nh; 233}; 234 235int call_fib4_notifier(struct notifier_block *nb, 236 enum fib_event_type event_type, 237 struct fib_notifier_info *info); 238int call_fib4_notifiers(struct net *net, enum fib_event_type event_type, 239 struct fib_notifier_info *info); 240 241int __net_init fib4_notifier_init(struct net *net); 242void __net_exit fib4_notifier_exit(struct net *net); 243 244void fib_info_notify_update(struct net *net, struct nl_info *info); 245int fib_notify(struct net *net, struct notifier_block *nb, 246 struct netlink_ext_ack *extack); 247 248struct 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 257struct 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 269int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 270 struct fib_result *res, int fib_flags); 271int fib_table_insert(struct net *, struct fib_table *, struct fib_config *, 272 struct netlink_ext_ack *extack); 273int fib_table_delete(struct net *, struct fib_table *, struct fib_config *, 274 struct netlink_ext_ack *extack); 275int fib_table_dump(struct fib_table *table, struct sk_buff *skb, 276 struct netlink_callback *cb, struct fib_dump_filter *filter); 277int fib_table_flush(struct net *net, struct fib_table *table, bool flush_all); 278struct fib_table *fib_trie_unmerge(struct fib_table *main_tb); 279void fib_table_flush_external(struct fib_table *table); 280void 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 287static 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 301static inline struct fib_table *fib_new_table(struct net *net, u32 id) 302{ 303 return fib_get_table(net, id); 304} 305 306static 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 326static inline bool fib4_has_custom_rules(const struct net *net) 327{ 328 return false; 329} 330 331static inline bool fib4_rule_default(const struct fib_rule *rule) 332{ 333 return true; 334} 335 336static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb, 337 struct netlink_ext_ack *extack) 338{ 339 return 0; 340} 341 342static inline unsigned int fib4_rules_seq_read(struct net *net) 343{ 344 return 0; 345} 346 347static 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 */ 355int __net_init fib4_rules_init(struct net *net); 356void __net_exit fib4_rules_exit(struct net *net); 357 358struct fib_table *fib_new_table(struct net *net, u32 id); 359struct fib_table *fib_get_table(struct net *net, u32 id); 360 361int __fib_lookup(struct net *net, struct flowi4 *flp, 362 struct fib_result *res, unsigned int flags); 363 364static 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 389out: 390 if (err == -EAGAIN) 391 err = -ENETUNREACH; 392 393 rcu_read_unlock(); 394 395 return err; 396} 397 398static inline bool fib4_has_custom_rules(const struct net *net) 399{ 400 return net->ipv4.fib_has_custom_rules; 401} 402 403bool fib4_rule_default(const struct fib_rule *rule); 404int fib4_rules_dump(struct net *net, struct notifier_block *nb, 405 struct netlink_ext_ack *extack); 406unsigned int fib4_rules_seq_read(struct net *net); 407 408static 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 */ 429extern const struct nla_policy rtm_ipv4_policy[]; 430void ip_fib_init(void); 431int 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); 434bool fib_info_nh_uses_dev(struct fib_info *fi, const struct net_device *dev); 435int 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 439static inline int fib_num_tclassid_users(struct net *net) 440{ 441 return atomic_read(&net->ipv4.fib_num_tclassid_users); 442} 443#else 444static inline int fib_num_tclassid_users(struct net *net) 445{ 446 return 0; 447} 448#endif 449int fib_unmerge(struct net *net); 450 451static inline bool nhc_l3mdev_matches_dev(const struct fib_nh_common *nhc, 452const 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 */ 462int ip_fib_check_default(__be32 gw, struct net_device *dev); 463int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force); 464int fib_sync_down_addr(struct net_device *dev, __be32 local); 465int fib_sync_up(struct net_device *dev, unsigned char nh_flags); 466void fib_sync_mtu(struct net_device *dev, u32 orig_mtu); 467void fib_nhc_update_mtu(struct fib_nh_common *nhc, u32 new, u32 orig); 468 469#ifdef CONFIG_IP_ROUTE_MULTIPATH 470int fib_multipath_hash(const struct net *net, const struct flowi4 *fl4, 471 const struct sk_buff *skb, struct flow_keys *flkeys); 472#endif 473int fib_check_nh(struct net *net, struct fib_nh *nh, u32 table, u8 scope, 474 struct netlink_ext_ack *extack); 475void fib_select_multipath(struct fib_result *res, int hash); 476void fib_select_path(struct net *net, struct fib_result *res, 477 struct flowi4 *fl4, const struct sk_buff *skb); 478 479int fib_nh_init(struct net *net, struct fib_nh *fib_nh, 480 struct fib_config *cfg, int nh_weight, 481 struct netlink_ext_ack *extack); 482void fib_nh_release(struct net *net, struct fib_nh *fib_nh); 483int fib_nh_common_init(struct net *net, struct fib_nh_common *nhc, 484 struct nlattr *fc_encap, u16 fc_encap_type, 485 void *cfg, gfp_t gfp_flags, 486 struct netlink_ext_ack *extack); 487void fib_nh_common_release(struct fib_nh_common *nhc); 488 489/* Exported by fib_trie.c */ 490void fib_alias_hw_flags_set(struct net *net, const struct fib_rt_info *fri); 491void fib_trie_init(void); 492struct fib_table *fib_trie_table(u32 id, struct fib_table *alias); 493bool fib_lookup_good_nhc(const struct fib_nh_common *nhc, int fib_flags, 494 const struct flowi4 *flp); 495 496static inline void fib_combine_itag(u32 *itag, const struct fib_result *res) 497{ 498#ifdef CONFIG_IP_ROUTE_CLASSID 499 struct fib_nh_common *nhc = res->nhc; 500#ifdef CONFIG_IP_MULTIPLE_TABLES 501 u32 rtag; 502#endif 503 if (nhc->nhc_family == AF_INET) { 504 struct fib_nh *nh; 505 506 nh = container_of(nhc, struct fib_nh, nh_common); 507 *itag = nh->nh_tclassid << 16; 508 } else { 509 *itag = 0; 510 } 511 512#ifdef CONFIG_IP_MULTIPLE_TABLES 513 rtag = res->tclassid; 514 if (*itag == 0) 515 *itag = (rtag<<16); 516 *itag |= (rtag>>16); 517#endif 518#endif 519} 520 521void fib_flush(struct net *net); 522void free_fib_info(struct fib_info *fi); 523 524static inline void fib_info_hold(struct fib_info *fi) 525{ 526 refcount_inc(&fi->fib_clntref); 527} 528 529static inline void fib_info_put(struct fib_info *fi) 530{ 531 if (refcount_dec_and_test(&fi->fib_clntref)) 532 free_fib_info(fi); 533} 534 535#ifdef CONFIG_PROC_FS 536int __net_init fib_proc_init(struct net *net); 537void __net_exit fib_proc_exit(struct net *net); 538#else 539static inline int fib_proc_init(struct net *net) 540{ 541 return 0; 542} 543static inline void fib_proc_exit(struct net *net) 544{ 545} 546#endif 547 548u32 ip_mtu_from_fib_result(struct fib_result *res, __be32 daddr); 549 550int ip_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh, 551 struct fib_dump_filter *filter, 552 struct netlink_callback *cb); 553 554int fib_nexthop_info(struct sk_buff *skb, const struct fib_nh_common *nh, 555 u8 rt_family, unsigned char *flags, bool skip_oif); 556int fib_add_nexthop(struct sk_buff *skb, const struct fib_nh_common *nh, 557 int nh_weight, u8 rt_family, u32 nh_tclassid); 558#endif /* _NET_FIB_H */ 559