2 * INET An implementation of the TCP/IP protocol suite for the LINUX
3 * operating system. INET is implemented using the BSD Socket
4 * interface as the means of communication with the user level.
6 * Definitions for the Forwarding Information Base.
8 * Authors: A.N.Kuznetsov, <kuznet@ms2.inr.ac.ru>
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
20 #include <linux/seq_file.h>
21 #include <linux/rcupdate.h>
22 #include <net/fib_rules.h>
23 #include <net/inetpeer.h>
24 #include <linux/percpu.h>
25 #include <linux/notifier.h>
26 #include <linux/refcount.h>
43 struct rtnexthop *fc_mp;
48 struct nl_info fc_nlinfo;
49 struct nlattr *fc_encap;
56 struct fib_nh_exception {
57 struct fib_nh_exception __rcu *fnhe_next;
62 unsigned long fnhe_expires;
63 struct rtable __rcu *fnhe_rth_input;
64 struct rtable __rcu *fnhe_rth_output;
65 unsigned long fnhe_stamp;
69 struct fnhe_hash_bucket {
70 struct fib_nh_exception __rcu *chain;
73 #define FNHE_HASH_SHIFT 11
74 #define FNHE_HASH_SIZE (1 << FNHE_HASH_SHIFT)
75 #define FNHE_RECLAIM_DEPTH 5
78 struct net_device *nh_dev;
79 struct hlist_node nh_hash;
80 struct fib_info *nh_parent;
81 unsigned int nh_flags;
82 unsigned char nh_scope;
83 #ifdef CONFIG_IP_ROUTE_MULTIPATH
85 atomic_t nh_upper_bound;
87 #ifdef CONFIG_IP_ROUTE_CLASSID
94 struct rtable __rcu * __percpu *nh_pcpu_rth_output;
95 struct rtable __rcu *nh_rth_input;
96 struct fnhe_hash_bucket __rcu *nh_exceptions;
97 struct lwtunnel_state *nh_lwtstate;
101 * This structure contains data shared by many of routes.
105 struct hlist_node fib_hash;
106 struct hlist_node fib_lhash;
109 refcount_t fib_clntref;
110 unsigned int fib_flags;
111 unsigned char fib_dead;
112 unsigned char fib_protocol;
113 unsigned char fib_scope;
114 unsigned char fib_type;
118 struct dst_metrics *fib_metrics;
119 #define fib_mtu fib_metrics->metrics[RTAX_MTU-1]
120 #define fib_window fib_metrics->metrics[RTAX_WINDOW-1]
121 #define fib_rtt fib_metrics->metrics[RTAX_RTT-1]
122 #define fib_advmss fib_metrics->metrics[RTAX_ADVMSS-1]
124 #ifdef CONFIG_IP_ROUTE_MULTIPATH
127 unsigned int fib_offload_cnt;
129 struct fib_nh fib_nh[0];
130 #define fib_dev fib_nh[0].nh_dev
134 #ifdef CONFIG_IP_MULTIPLE_TABLES
141 unsigned char prefixlen;
142 unsigned char nh_sel;
147 struct fib_table *table;
148 struct hlist_head *fa_head;
151 struct fib_result_nl {
152 __be32 fl_addr; /* To be looked up*/
154 unsigned char fl_tos;
155 unsigned char fl_scope;
156 unsigned char tb_id_in;
158 unsigned char tb_id; /* Results */
159 unsigned char prefixlen;
160 unsigned char nh_sel;
166 #ifdef CONFIG_IP_ROUTE_MULTIPATH
167 #define FIB_RES_NH(res) ((res).fi->fib_nh[(res).nh_sel])
168 #else /* CONFIG_IP_ROUTE_MULTIPATH */
169 #define FIB_RES_NH(res) ((res).fi->fib_nh[0])
170 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
172 #ifdef CONFIG_IP_MULTIPLE_TABLES
173 #define FIB_TABLE_HASHSZ 256
175 #define FIB_TABLE_HASHSZ 2
178 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
180 static inline void fib_info_offload_inc(struct fib_info *fi)
182 fi->fib_offload_cnt++;
183 fi->fib_flags |= RTNH_F_OFFLOAD;
186 static inline void fib_info_offload_dec(struct fib_info *fi)
188 if (--fi->fib_offload_cnt == 0)
189 fi->fib_flags &= ~RTNH_F_OFFLOAD;
192 #define FIB_RES_SADDR(net, res) \
193 ((FIB_RES_NH(res).nh_saddr_genid == \
194 atomic_read(&(net)->ipv4.dev_addr_genid)) ? \
195 FIB_RES_NH(res).nh_saddr : \
196 fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
197 #define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw)
198 #define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev)
199 #define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif)
201 #define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \
202 FIB_RES_SADDR(net, res))
204 struct fib_notifier_info {
208 struct fib_entry_notifier_info {
209 struct fib_notifier_info info; /* must be first */
218 struct fib_rule_notifier_info {
219 struct fib_notifier_info info; /* must be first */
220 struct fib_rule *rule;
223 struct fib_nh_notifier_info {
224 struct fib_notifier_info info; /* must be first */
225 struct fib_nh *fib_nh;
228 enum fib_event_type {
229 FIB_EVENT_ENTRY_REPLACE,
230 FIB_EVENT_ENTRY_APPEND,
239 int register_fib_notifier(struct notifier_block *nb,
240 void (*cb)(struct notifier_block *nb));
241 int unregister_fib_notifier(struct notifier_block *nb);
242 int call_fib_notifier(struct notifier_block *nb, struct net *net,
243 enum fib_event_type event_type,
244 struct fib_notifier_info *info);
245 int call_fib_notifiers(struct net *net, enum fib_event_type event_type,
246 struct fib_notifier_info *info);
248 void fib_notify(struct net *net, struct notifier_block *nb);
249 #ifdef CONFIG_IP_MULTIPLE_TABLES
250 void fib_rules_notify(struct net *net, struct notifier_block *nb);
252 static inline void fib_rules_notify(struct net *net, struct notifier_block *nb)
258 struct hlist_node tb_hlist;
262 unsigned long *tb_data;
263 unsigned long __data[0];
266 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
267 struct fib_result *res, int fib_flags);
268 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *,
269 struct netlink_ext_ack *extack);
270 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *,
271 struct netlink_ext_ack *extack);
272 int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
273 struct netlink_callback *cb);
274 int fib_table_flush(struct net *net, struct fib_table *table);
275 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
276 void fib_table_flush_external(struct fib_table *table);
277 void fib_free_table(struct fib_table *tb);
279 #ifndef CONFIG_IP_MULTIPLE_TABLES
281 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
282 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1))
284 static inline struct fib_table *fib_get_table(struct net *net, u32 id)
286 struct hlist_node *tb_hlist;
287 struct hlist_head *ptr;
289 ptr = id == RT_TABLE_LOCAL ?
290 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
291 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
293 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));
295 return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
298 static inline struct fib_table *fib_new_table(struct net *net, u32 id)
300 return fib_get_table(net, id);
303 static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
304 struct fib_result *res, unsigned int flags)
306 struct fib_table *tb;
307 int err = -ENETUNREACH;
311 tb = fib_get_table(net, RT_TABLE_MAIN);
313 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF);
323 static inline bool fib4_rule_default(const struct fib_rule *rule)
328 #else /* CONFIG_IP_MULTIPLE_TABLES */
329 int __net_init fib4_rules_init(struct net *net);
330 void __net_exit fib4_rules_exit(struct net *net);
332 struct fib_table *fib_new_table(struct net *net, u32 id);
333 struct fib_table *fib_get_table(struct net *net, u32 id);
335 int __fib_lookup(struct net *net, struct flowi4 *flp,
336 struct fib_result *res, unsigned int flags);
338 static inline int fib_lookup(struct net *net, struct flowi4 *flp,
339 struct fib_result *res, unsigned int flags)
341 struct fib_table *tb;
342 int err = -ENETUNREACH;
344 flags |= FIB_LOOKUP_NOREF;
345 if (net->ipv4.fib_has_custom_rules)
346 return __fib_lookup(net, flp, res, flags);
352 tb = rcu_dereference_rtnl(net->ipv4.fib_main);
354 err = fib_table_lookup(tb, flp, res, flags);
359 tb = rcu_dereference_rtnl(net->ipv4.fib_default);
361 err = fib_table_lookup(tb, flp, res, flags);
372 bool fib4_rule_default(const struct fib_rule *rule);
374 #endif /* CONFIG_IP_MULTIPLE_TABLES */
376 /* Exported by fib_frontend.c */
377 extern const struct nla_policy rtm_ipv4_policy[];
378 void ip_fib_init(void);
379 __be32 fib_compute_spec_dst(struct sk_buff *skb);
380 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
381 u8 tos, int oif, struct net_device *dev,
382 struct in_device *idev, u32 *itag);
383 #ifdef CONFIG_IP_ROUTE_CLASSID
384 static inline int fib_num_tclassid_users(struct net *net)
386 return net->ipv4.fib_num_tclassid_users;
389 static inline int fib_num_tclassid_users(struct net *net)
394 int fib_unmerge(struct net *net);
396 /* Exported by fib_semantics.c */
397 int ip_fib_check_default(__be32 gw, struct net_device *dev);
398 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
399 int fib_sync_down_addr(struct net_device *dev, __be32 local);
400 int fib_sync_up(struct net_device *dev, unsigned int nh_flags);
402 #ifdef CONFIG_IP_ROUTE_MULTIPATH
403 int fib_multipath_hash(const struct fib_info *fi, const struct flowi4 *fl4,
404 const struct sk_buff *skb);
406 void fib_select_multipath(struct fib_result *res, int hash);
407 void fib_select_path(struct net *net, struct fib_result *res,
408 struct flowi4 *fl4, const struct sk_buff *skb);
410 /* Exported by fib_trie.c */
411 void fib_trie_init(void);
412 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
414 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
416 #ifdef CONFIG_IP_ROUTE_CLASSID
417 #ifdef CONFIG_IP_MULTIPLE_TABLES
420 *itag = FIB_RES_NH(*res).nh_tclassid<<16;
421 #ifdef CONFIG_IP_MULTIPLE_TABLES
422 rtag = res->tclassid;
430 void free_fib_info(struct fib_info *fi);
432 static inline void fib_info_hold(struct fib_info *fi)
434 refcount_inc(&fi->fib_clntref);
437 static inline void fib_info_put(struct fib_info *fi)
439 if (refcount_dec_and_test(&fi->fib_clntref))
443 #ifdef CONFIG_PROC_FS
444 int __net_init fib_proc_init(struct net *net);
445 void __net_exit fib_proc_exit(struct net *net);
447 static inline int fib_proc_init(struct net *net)
451 static inline void fib_proc_exit(struct net *net)
456 #endif /* _NET_FIB_H */