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>
42 struct rtnexthop *fc_mp;
47 struct nl_info fc_nlinfo;
48 struct nlattr *fc_encap;
55 struct fib_nh_exception {
56 struct fib_nh_exception __rcu *fnhe_next;
61 unsigned long fnhe_expires;
62 struct rtable __rcu *fnhe_rth_input;
63 struct rtable __rcu *fnhe_rth_output;
64 unsigned long fnhe_stamp;
68 struct fnhe_hash_bucket {
69 struct fib_nh_exception __rcu *chain;
72 #define FNHE_HASH_SHIFT 11
73 #define FNHE_HASH_SIZE (1 << FNHE_HASH_SHIFT)
74 #define FNHE_RECLAIM_DEPTH 5
77 struct net_device *nh_dev;
78 struct hlist_node nh_hash;
79 struct fib_info *nh_parent;
80 unsigned int nh_flags;
81 unsigned char nh_scope;
82 #ifdef CONFIG_IP_ROUTE_MULTIPATH
84 atomic_t nh_upper_bound;
86 #ifdef CONFIG_IP_ROUTE_CLASSID
93 struct rtable __rcu * __percpu *nh_pcpu_rth_output;
94 struct rtable __rcu *nh_rth_input;
95 struct fnhe_hash_bucket __rcu *nh_exceptions;
96 struct lwtunnel_state *nh_lwtstate;
100 * This structure contains data shared by many of routes.
104 struct hlist_node fib_hash;
105 struct hlist_node fib_lhash;
108 atomic_t fib_clntref;
109 unsigned int fib_flags;
110 unsigned char fib_dead;
111 unsigned char fib_protocol;
112 unsigned char fib_scope;
113 unsigned char fib_type;
117 struct dst_metrics *fib_metrics;
118 #define fib_mtu fib_metrics->metrics[RTAX_MTU-1]
119 #define fib_window fib_metrics->metrics[RTAX_WINDOW-1]
120 #define fib_rtt fib_metrics->metrics[RTAX_RTT-1]
121 #define fib_advmss fib_metrics->metrics[RTAX_ADVMSS-1]
123 #ifdef CONFIG_IP_ROUTE_MULTIPATH
126 unsigned int fib_offload_cnt;
128 struct fib_nh fib_nh[0];
129 #define fib_dev fib_nh[0].nh_dev
133 #ifdef CONFIG_IP_MULTIPLE_TABLES
140 unsigned char prefixlen;
141 unsigned char nh_sel;
146 struct fib_table *table;
147 struct hlist_head *fa_head;
150 struct fib_result_nl {
151 __be32 fl_addr; /* To be looked up*/
153 unsigned char fl_tos;
154 unsigned char fl_scope;
155 unsigned char tb_id_in;
157 unsigned char tb_id; /* Results */
158 unsigned char prefixlen;
159 unsigned char nh_sel;
165 #ifdef CONFIG_IP_ROUTE_MULTIPATH
166 #define FIB_RES_NH(res) ((res).fi->fib_nh[(res).nh_sel])
167 #else /* CONFIG_IP_ROUTE_MULTIPATH */
168 #define FIB_RES_NH(res) ((res).fi->fib_nh[0])
169 #endif /* CONFIG_IP_ROUTE_MULTIPATH */
171 #ifdef CONFIG_IP_MULTIPLE_TABLES
172 #define FIB_TABLE_HASHSZ 256
174 #define FIB_TABLE_HASHSZ 2
177 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
179 static inline void fib_info_offload_inc(struct fib_info *fi)
181 fi->fib_offload_cnt++;
182 fi->fib_flags |= RTNH_F_OFFLOAD;
185 static inline void fib_info_offload_dec(struct fib_info *fi)
187 if (--fi->fib_offload_cnt == 0)
188 fi->fib_flags &= ~RTNH_F_OFFLOAD;
191 #define FIB_RES_SADDR(net, res) \
192 ((FIB_RES_NH(res).nh_saddr_genid == \
193 atomic_read(&(net)->ipv4.dev_addr_genid)) ? \
194 FIB_RES_NH(res).nh_saddr : \
195 fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
196 #define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw)
197 #define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev)
198 #define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif)
200 #define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \
201 FIB_RES_SADDR(net, res))
203 struct fib_notifier_info {
207 struct fib_entry_notifier_info {
208 struct fib_notifier_info info; /* must be first */
217 struct fib_rule_notifier_info {
218 struct fib_notifier_info info; /* must be first */
219 struct fib_rule *rule;
222 struct fib_nh_notifier_info {
223 struct fib_notifier_info info; /* must be first */
224 struct fib_nh *fib_nh;
227 enum fib_event_type {
228 FIB_EVENT_ENTRY_REPLACE,
229 FIB_EVENT_ENTRY_APPEND,
238 int register_fib_notifier(struct notifier_block *nb,
239 void (*cb)(struct notifier_block *nb));
240 int unregister_fib_notifier(struct notifier_block *nb);
241 int call_fib_notifier(struct notifier_block *nb, struct net *net,
242 enum fib_event_type event_type,
243 struct fib_notifier_info *info);
244 int call_fib_notifiers(struct net *net, enum fib_event_type event_type,
245 struct fib_notifier_info *info);
247 void fib_notify(struct net *net, struct notifier_block *nb);
248 #ifdef CONFIG_IP_MULTIPLE_TABLES
249 void fib_rules_notify(struct net *net, struct notifier_block *nb);
251 static inline void fib_rules_notify(struct net *net, struct notifier_block *nb)
257 struct hlist_node tb_hlist;
261 unsigned long *tb_data;
262 unsigned long __data[0];
265 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
266 struct fib_result *res, int fib_flags);
267 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *,
268 struct netlink_ext_ack *extack);
269 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *,
270 struct netlink_ext_ack *extack);
271 int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
272 struct netlink_callback *cb);
273 int fib_table_flush(struct net *net, struct fib_table *table);
274 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
275 void fib_table_flush_external(struct fib_table *table);
276 void fib_free_table(struct fib_table *tb);
278 #ifndef CONFIG_IP_MULTIPLE_TABLES
280 #define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
281 #define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1))
283 static inline struct fib_table *fib_get_table(struct net *net, u32 id)
285 struct hlist_node *tb_hlist;
286 struct hlist_head *ptr;
288 ptr = id == RT_TABLE_LOCAL ?
289 &net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
290 &net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
292 tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));
294 return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
297 static inline struct fib_table *fib_new_table(struct net *net, u32 id)
299 return fib_get_table(net, id);
302 static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
303 struct fib_result *res, unsigned int flags)
305 struct fib_table *tb;
306 int err = -ENETUNREACH;
310 tb = fib_get_table(net, RT_TABLE_MAIN);
312 err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF);
322 static inline bool fib4_rule_default(const struct fib_rule *rule)
327 #else /* CONFIG_IP_MULTIPLE_TABLES */
328 int __net_init fib4_rules_init(struct net *net);
329 void __net_exit fib4_rules_exit(struct net *net);
331 struct fib_table *fib_new_table(struct net *net, u32 id);
332 struct fib_table *fib_get_table(struct net *net, u32 id);
334 int __fib_lookup(struct net *net, struct flowi4 *flp,
335 struct fib_result *res, unsigned int flags);
337 static inline int fib_lookup(struct net *net, struct flowi4 *flp,
338 struct fib_result *res, unsigned int flags)
340 struct fib_table *tb;
341 int err = -ENETUNREACH;
343 flags |= FIB_LOOKUP_NOREF;
344 if (net->ipv4.fib_has_custom_rules)
345 return __fib_lookup(net, flp, res, flags);
351 tb = rcu_dereference_rtnl(net->ipv4.fib_main);
353 err = fib_table_lookup(tb, flp, res, flags);
358 tb = rcu_dereference_rtnl(net->ipv4.fib_default);
360 err = fib_table_lookup(tb, flp, res, flags);
371 bool fib4_rule_default(const struct fib_rule *rule);
373 #endif /* CONFIG_IP_MULTIPLE_TABLES */
375 /* Exported by fib_frontend.c */
376 extern const struct nla_policy rtm_ipv4_policy[];
377 void ip_fib_init(void);
378 __be32 fib_compute_spec_dst(struct sk_buff *skb);
379 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
380 u8 tos, int oif, struct net_device *dev,
381 struct in_device *idev, u32 *itag);
382 #ifdef CONFIG_IP_ROUTE_CLASSID
383 static inline int fib_num_tclassid_users(struct net *net)
385 return net->ipv4.fib_num_tclassid_users;
388 static inline int fib_num_tclassid_users(struct net *net)
393 int fib_unmerge(struct net *net);
395 /* Exported by fib_semantics.c */
396 int ip_fib_check_default(__be32 gw, struct net_device *dev);
397 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
398 int fib_sync_down_addr(struct net_device *dev, __be32 local);
399 int fib_sync_up(struct net_device *dev, unsigned int nh_flags);
401 #ifdef CONFIG_IP_ROUTE_MULTIPATH
402 int fib_multipath_hash(const struct fib_info *fi, const struct flowi4 *fl4,
403 const struct sk_buff *skb);
405 void fib_select_multipath(struct fib_result *res, int hash);
406 void fib_select_path(struct net *net, struct fib_result *res,
407 struct flowi4 *fl4, const struct sk_buff *skb);
409 /* Exported by fib_trie.c */
410 void fib_trie_init(void);
411 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
413 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
415 #ifdef CONFIG_IP_ROUTE_CLASSID
416 #ifdef CONFIG_IP_MULTIPLE_TABLES
419 *itag = FIB_RES_NH(*res).nh_tclassid<<16;
420 #ifdef CONFIG_IP_MULTIPLE_TABLES
421 rtag = res->tclassid;
429 void free_fib_info(struct fib_info *fi);
431 static inline void fib_info_hold(struct fib_info *fi)
433 atomic_inc(&fi->fib_clntref);
436 static inline void fib_info_put(struct fib_info *fi)
438 if (atomic_dec_and_test(&fi->fib_clntref))
442 #ifdef CONFIG_PROC_FS
443 int __net_init fib_proc_init(struct net *net);
444 void __net_exit fib_proc_exit(struct net *net);
446 static inline int fib_proc_init(struct net *net)
450 static inline void fib_proc_exit(struct net *net)
455 #endif /* _NET_FIB_H */