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v4.6
  1/*
  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.
  5 *
  6 *		Definitions for the Forwarding Information Base.
  7 *
  8 * Authors:	A.N.Kuznetsov, <kuznet@ms2.inr.ac.ru>
  9 *
 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.
 14 */
 15
 16#ifndef _NET_IP_FIB_H
 17#define _NET_IP_FIB_H
 18
 19#include <net/flow.h>
 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
 26struct fib_config {
 27	u8			fc_dst_len;
 28	u8			fc_tos;
 29	u8			fc_protocol;
 30	u8			fc_scope;
 31	u8			fc_type;
 32	/* 3 bytes unused */
 33	u32			fc_table;
 34	__be32			fc_dst;
 35	__be32			fc_gw;
 36	int			fc_oif;
 37	u32			fc_flags;
 38	u32			fc_priority;
 39	__be32			fc_prefsrc;
 40	struct nlattr		*fc_mx;
 41	struct rtnexthop	*fc_mp;
 42	int			fc_mx_len;
 43	int			fc_mp_len;
 44	u32			fc_flow;
 45	u32			fc_nlflags;
 46	struct nl_info		fc_nlinfo;
 47	struct nlattr		*fc_encap;
 48	u16			fc_encap_type;
 49};
 50
 51struct fib_info;
 52struct rtable;
 53
 54struct fib_nh_exception {
 55	struct fib_nh_exception __rcu	*fnhe_next;
 56	int				fnhe_genid;
 57	__be32				fnhe_daddr;
 58	u32				fnhe_pmtu;
 59	__be32				fnhe_gw;
 60	unsigned long			fnhe_expires;
 61	struct rtable __rcu		*fnhe_rth_input;
 62	struct rtable __rcu		*fnhe_rth_output;
 63	unsigned long			fnhe_stamp;
 64	struct rcu_head			rcu;
 65};
 66
 67struct fnhe_hash_bucket {
 68	struct fib_nh_exception __rcu	*chain;
 69};
 70
 71#define FNHE_HASH_SHIFT		11
 72#define FNHE_HASH_SIZE		(1 << FNHE_HASH_SHIFT)
 73#define FNHE_RECLAIM_DEPTH	5
 74
 75struct fib_nh {
 76	struct net_device	*nh_dev;
 77	struct hlist_node	nh_hash;
 78	struct fib_info		*nh_parent;
 79	unsigned int		nh_flags;
 80	unsigned char		nh_scope;
 81#ifdef CONFIG_IP_ROUTE_MULTIPATH
 82	int			nh_weight;
 83	atomic_t		nh_upper_bound;
 84#endif
 85#ifdef CONFIG_IP_ROUTE_CLASSID
 86	__u32			nh_tclassid;
 87#endif
 88	int			nh_oif;
 89	__be32			nh_gw;
 90	__be32			nh_saddr;
 91	int			nh_saddr_genid;
 92	struct rtable __rcu * __percpu *nh_pcpu_rth_output;
 93	struct rtable __rcu	*nh_rth_input;
 94	struct fnhe_hash_bucket	__rcu *nh_exceptions;
 95	struct lwtunnel_state	*nh_lwtstate;
 96};
 97
 98/*
 99 * This structure contains data shared by many of routes.
100 */
101
102struct fib_info {
103	struct hlist_node	fib_hash;
104	struct hlist_node	fib_lhash;
105	struct net		*fib_net;
106	int			fib_treeref;
107	atomic_t		fib_clntref;
108	unsigned int		fib_flags;
109	unsigned char		fib_dead;
110	unsigned char		fib_protocol;
111	unsigned char		fib_scope;
112	unsigned char		fib_type;
113	__be32			fib_prefsrc;
 
114	u32			fib_priority;
115	u32			*fib_metrics;
116#define fib_mtu fib_metrics[RTAX_MTU-1]
117#define fib_window fib_metrics[RTAX_WINDOW-1]
118#define fib_rtt fib_metrics[RTAX_RTT-1]
119#define fib_advmss fib_metrics[RTAX_ADVMSS-1]
120	int			fib_nhs;
121#ifdef CONFIG_IP_ROUTE_MULTIPATH
122	int			fib_weight;
123#endif
 
124	struct rcu_head		rcu;
125	struct fib_nh		fib_nh[0];
126#define fib_dev		fib_nh[0].nh_dev
127};
128
129
130#ifdef CONFIG_IP_MULTIPLE_TABLES
131struct fib_rule;
132#endif
133
134struct fib_table;
135struct fib_result {
136	unsigned char	prefixlen;
137	unsigned char	nh_sel;
138	unsigned char	type;
139	unsigned char	scope;
140	u32		tclassid;
141	struct fib_info *fi;
142	struct fib_table *table;
143	struct hlist_head *fa_head;
144};
145
146struct fib_result_nl {
147	__be32		fl_addr;   /* To be looked up*/
148	u32		fl_mark;
149	unsigned char	fl_tos;
150	unsigned char   fl_scope;
151	unsigned char   tb_id_in;
152
153	unsigned char   tb_id;      /* Results */
154	unsigned char	prefixlen;
155	unsigned char	nh_sel;
156	unsigned char	type;
157	unsigned char	scope;
158	int             err;      
159};
160
161#ifdef CONFIG_IP_ROUTE_MULTIPATH
162#define FIB_RES_NH(res)		((res).fi->fib_nh[(res).nh_sel])
163#else /* CONFIG_IP_ROUTE_MULTIPATH */
164#define FIB_RES_NH(res)		((res).fi->fib_nh[0])
165#endif /* CONFIG_IP_ROUTE_MULTIPATH */
166
167#ifdef CONFIG_IP_MULTIPLE_TABLES
168#define FIB_TABLE_HASHSZ 256
169#else
170#define FIB_TABLE_HASHSZ 2
171#endif
172
173__be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
174
 
 
 
 
 
 
 
 
 
 
 
 
175#define FIB_RES_SADDR(net, res)				\
176	((FIB_RES_NH(res).nh_saddr_genid ==		\
177	  atomic_read(&(net)->ipv4.dev_addr_genid)) ?	\
178	 FIB_RES_NH(res).nh_saddr :			\
179	 fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
180#define FIB_RES_GW(res)			(FIB_RES_NH(res).nh_gw)
181#define FIB_RES_DEV(res)		(FIB_RES_NH(res).nh_dev)
182#define FIB_RES_OIF(res)		(FIB_RES_NH(res).nh_oif)
183
184#define FIB_RES_PREFSRC(net, res)	((res).fi->fib_prefsrc ? : \
185					 FIB_RES_SADDR(net, res))
186
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
187struct fib_table {
188	struct hlist_node	tb_hlist;
189	u32			tb_id;
190	int			tb_num_default;
191	struct rcu_head		rcu;
192	unsigned long 		*tb_data;
193	unsigned long		__data[0];
194};
195
196int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
197		     struct fib_result *res, int fib_flags);
198int fib_table_insert(struct fib_table *, struct fib_config *);
199int fib_table_delete(struct fib_table *, struct fib_config *);
200int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
201		   struct netlink_callback *cb);
202int fib_table_flush(struct fib_table *table);
203struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
204void fib_table_flush_external(struct fib_table *table);
205void fib_free_table(struct fib_table *tb);
206
207#ifndef CONFIG_IP_MULTIPLE_TABLES
208
209#define TABLE_LOCAL_INDEX	(RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
210#define TABLE_MAIN_INDEX	(RT_TABLE_MAIN  & (FIB_TABLE_HASHSZ - 1))
211
212static inline struct fib_table *fib_get_table(struct net *net, u32 id)
213{
214	struct hlist_node *tb_hlist;
215	struct hlist_head *ptr;
216
217	ptr = id == RT_TABLE_LOCAL ?
218		&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
219		&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
220
221	tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));
222
223	return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
224}
225
226static inline struct fib_table *fib_new_table(struct net *net, u32 id)
227{
228	return fib_get_table(net, id);
229}
230
231static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
232			     struct fib_result *res, unsigned int flags)
233{
234	struct fib_table *tb;
235	int err = -ENETUNREACH;
236
237	rcu_read_lock();
238
239	tb = fib_get_table(net, RT_TABLE_MAIN);
240	if (tb)
241		err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF);
242
243	if (err == -EAGAIN)
244		err = -ENETUNREACH;
245
246	rcu_read_unlock();
247
248	return err;
249}
250
251#else /* CONFIG_IP_MULTIPLE_TABLES */
252int __net_init fib4_rules_init(struct net *net);
253void __net_exit fib4_rules_exit(struct net *net);
254
255struct fib_table *fib_new_table(struct net *net, u32 id);
256struct fib_table *fib_get_table(struct net *net, u32 id);
257
258int __fib_lookup(struct net *net, struct flowi4 *flp,
259		 struct fib_result *res, unsigned int flags);
260
261static inline int fib_lookup(struct net *net, struct flowi4 *flp,
262			     struct fib_result *res, unsigned int flags)
263{
264	struct fib_table *tb;
265	int err = -ENETUNREACH;
266
267	flags |= FIB_LOOKUP_NOREF;
268	if (net->ipv4.fib_has_custom_rules)
269		return __fib_lookup(net, flp, res, flags);
270
271	rcu_read_lock();
272
273	res->tclassid = 0;
274
275	tb = rcu_dereference_rtnl(net->ipv4.fib_main);
276	if (tb)
277		err = fib_table_lookup(tb, flp, res, flags);
278
279	if (!err)
280		goto out;
281
282	tb = rcu_dereference_rtnl(net->ipv4.fib_default);
283	if (tb)
284		err = fib_table_lookup(tb, flp, res, flags);
285
286out:
287	if (err == -EAGAIN)
288		err = -ENETUNREACH;
289
290	rcu_read_unlock();
291
292	return err;
293}
294
295#endif /* CONFIG_IP_MULTIPLE_TABLES */
296
297/* Exported by fib_frontend.c */
298extern const struct nla_policy rtm_ipv4_policy[];
299void ip_fib_init(void);
300__be32 fib_compute_spec_dst(struct sk_buff *skb);
301int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
302			u8 tos, int oif, struct net_device *dev,
303			struct in_device *idev, u32 *itag);
304void fib_select_default(const struct flowi4 *flp, struct fib_result *res);
305#ifdef CONFIG_IP_ROUTE_CLASSID
306static inline int fib_num_tclassid_users(struct net *net)
307{
308	return net->ipv4.fib_num_tclassid_users;
309}
310#else
311static inline int fib_num_tclassid_users(struct net *net)
312{
313	return 0;
314}
315#endif
316int fib_unmerge(struct net *net);
317void fib_flush_external(struct net *net);
318
319/* Exported by fib_semantics.c */
320int ip_fib_check_default(__be32 gw, struct net_device *dev);
321int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
322int fib_sync_down_addr(struct net *net, __be32 local);
323int fib_sync_up(struct net_device *dev, unsigned int nh_flags);
324
325extern u32 fib_multipath_secret __read_mostly;
326
327static inline int fib_multipath_hash(__be32 saddr, __be32 daddr)
328{
329	return jhash_2words((__force u32)saddr, (__force u32)daddr,
330			    fib_multipath_secret) >> 1;
331}
332
333void fib_select_multipath(struct fib_result *res, int hash);
334void fib_select_path(struct net *net, struct fib_result *res,
335		     struct flowi4 *fl4, int mp_hash);
336
337/* Exported by fib_trie.c */
338void fib_trie_init(void);
339struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
340
341static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
342{
343#ifdef CONFIG_IP_ROUTE_CLASSID
344#ifdef CONFIG_IP_MULTIPLE_TABLES
345	u32 rtag;
346#endif
347	*itag = FIB_RES_NH(*res).nh_tclassid<<16;
348#ifdef CONFIG_IP_MULTIPLE_TABLES
349	rtag = res->tclassid;
350	if (*itag == 0)
351		*itag = (rtag<<16);
352	*itag |= (rtag>>16);
353#endif
354#endif
355}
356
357void free_fib_info(struct fib_info *fi);
 
 
 
 
 
358
359static inline void fib_info_put(struct fib_info *fi)
360{
361	if (atomic_dec_and_test(&fi->fib_clntref))
362		free_fib_info(fi);
363}
364
365#ifdef CONFIG_PROC_FS
366int __net_init fib_proc_init(struct net *net);
367void __net_exit fib_proc_exit(struct net *net);
368#else
369static inline int fib_proc_init(struct net *net)
370{
371	return 0;
372}
373static inline void fib_proc_exit(struct net *net)
374{
375}
376#endif
377
378#endif  /* _NET_FIB_H */
v4.10.11
  1/*
  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.
  5 *
  6 *		Definitions for the Forwarding Information Base.
  7 *
  8 * Authors:	A.N.Kuznetsov, <kuznet@ms2.inr.ac.ru>
  9 *
 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.
 14 */
 15
 16#ifndef _NET_IP_FIB_H
 17#define _NET_IP_FIB_H
 18
 19#include <net/flow.h>
 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
 27struct fib_config {
 28	u8			fc_dst_len;
 29	u8			fc_tos;
 30	u8			fc_protocol;
 31	u8			fc_scope;
 32	u8			fc_type;
 33	/* 3 bytes unused */
 34	u32			fc_table;
 35	__be32			fc_dst;
 36	__be32			fc_gw;
 37	int			fc_oif;
 38	u32			fc_flags;
 39	u32			fc_priority;
 40	__be32			fc_prefsrc;
 41	struct nlattr		*fc_mx;
 42	struct rtnexthop	*fc_mp;
 43	int			fc_mx_len;
 44	int			fc_mp_len;
 45	u32			fc_flow;
 46	u32			fc_nlflags;
 47	struct nl_info		fc_nlinfo;
 48	struct nlattr		*fc_encap;
 49	u16			fc_encap_type;
 50};
 51
 52struct fib_info;
 53struct rtable;
 54
 55struct fib_nh_exception {
 56	struct fib_nh_exception __rcu	*fnhe_next;
 57	int				fnhe_genid;
 58	__be32				fnhe_daddr;
 59	u32				fnhe_pmtu;
 60	__be32				fnhe_gw;
 61	unsigned long			fnhe_expires;
 62	struct rtable __rcu		*fnhe_rth_input;
 63	struct rtable __rcu		*fnhe_rth_output;
 64	unsigned long			fnhe_stamp;
 65	struct rcu_head			rcu;
 66};
 67
 68struct fnhe_hash_bucket {
 69	struct fib_nh_exception __rcu	*chain;
 70};
 71
 72#define FNHE_HASH_SHIFT		11
 73#define FNHE_HASH_SIZE		(1 << FNHE_HASH_SHIFT)
 74#define FNHE_RECLAIM_DEPTH	5
 75
 76struct fib_nh {
 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
 83	int			nh_weight;
 84	atomic_t		nh_upper_bound;
 85#endif
 86#ifdef CONFIG_IP_ROUTE_CLASSID
 87	__u32			nh_tclassid;
 88#endif
 89	int			nh_oif;
 90	__be32			nh_gw;
 91	__be32			nh_saddr;
 92	int			nh_saddr_genid;
 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;
 97};
 98
 99/*
100 * This structure contains data shared by many of routes.
101 */
102
103struct fib_info {
104	struct hlist_node	fib_hash;
105	struct hlist_node	fib_lhash;
106	struct net		*fib_net;
107	int			fib_treeref;
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;
114	__be32			fib_prefsrc;
115	u32			fib_tb_id;
116	u32			fib_priority;
117	u32			*fib_metrics;
118#define fib_mtu fib_metrics[RTAX_MTU-1]
119#define fib_window fib_metrics[RTAX_WINDOW-1]
120#define fib_rtt fib_metrics[RTAX_RTT-1]
121#define fib_advmss fib_metrics[RTAX_ADVMSS-1]
122	int			fib_nhs;
123#ifdef CONFIG_IP_ROUTE_MULTIPATH
124	int			fib_weight;
125#endif
126	unsigned int		fib_offload_cnt;
127	struct rcu_head		rcu;
128	struct fib_nh		fib_nh[0];
129#define fib_dev		fib_nh[0].nh_dev
130};
131
132
133#ifdef CONFIG_IP_MULTIPLE_TABLES
134struct fib_rule;
135#endif
136
137struct fib_table;
138struct fib_result {
139	unsigned char	prefixlen;
140	unsigned char	nh_sel;
141	unsigned char	type;
142	unsigned char	scope;
143	u32		tclassid;
144	struct fib_info *fi;
145	struct fib_table *table;
146	struct hlist_head *fa_head;
147};
148
149struct fib_result_nl {
150	__be32		fl_addr;   /* To be looked up*/
151	u32		fl_mark;
152	unsigned char	fl_tos;
153	unsigned char   fl_scope;
154	unsigned char   tb_id_in;
155
156	unsigned char   tb_id;      /* Results */
157	unsigned char	prefixlen;
158	unsigned char	nh_sel;
159	unsigned char	type;
160	unsigned char	scope;
161	int             err;      
162};
163
164#ifdef CONFIG_IP_ROUTE_MULTIPATH
165#define FIB_RES_NH(res)		((res).fi->fib_nh[(res).nh_sel])
166#else /* CONFIG_IP_ROUTE_MULTIPATH */
167#define FIB_RES_NH(res)		((res).fi->fib_nh[0])
168#endif /* CONFIG_IP_ROUTE_MULTIPATH */
169
170#ifdef CONFIG_IP_MULTIPLE_TABLES
171#define FIB_TABLE_HASHSZ 256
172#else
173#define FIB_TABLE_HASHSZ 2
174#endif
175
176__be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
177
178static inline void fib_info_offload_inc(struct fib_info *fi)
179{
180	fi->fib_offload_cnt++;
181	fi->fib_flags |= RTNH_F_OFFLOAD;
182}
183
184static inline void fib_info_offload_dec(struct fib_info *fi)
185{
186	if (--fi->fib_offload_cnt == 0)
187		fi->fib_flags &= ~RTNH_F_OFFLOAD;
188}
189
190#define FIB_RES_SADDR(net, res)				\
191	((FIB_RES_NH(res).nh_saddr_genid ==		\
192	  atomic_read(&(net)->ipv4.dev_addr_genid)) ?	\
193	 FIB_RES_NH(res).nh_saddr :			\
194	 fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
195#define FIB_RES_GW(res)			(FIB_RES_NH(res).nh_gw)
196#define FIB_RES_DEV(res)		(FIB_RES_NH(res).nh_dev)
197#define FIB_RES_OIF(res)		(FIB_RES_NH(res).nh_oif)
198
199#define FIB_RES_PREFSRC(net, res)	((res).fi->fib_prefsrc ? : \
200					 FIB_RES_SADDR(net, res))
201
202struct fib_notifier_info {
203	struct net *net;
204};
205
206struct fib_entry_notifier_info {
207	struct fib_notifier_info info; /* must be first */
208	u32 dst;
209	int dst_len;
210	struct fib_info *fi;
211	u8 tos;
212	u8 type;
213	u32 tb_id;
214	u32 nlflags;
215};
216
217enum fib_event_type {
218	FIB_EVENT_ENTRY_ADD,
219	FIB_EVENT_ENTRY_DEL,
220	FIB_EVENT_RULE_ADD,
221	FIB_EVENT_RULE_DEL,
222};
223
224int register_fib_notifier(struct notifier_block *nb,
225			  void (*cb)(struct notifier_block *nb));
226int unregister_fib_notifier(struct notifier_block *nb);
227int call_fib_notifiers(struct net *net, enum fib_event_type event_type,
228		       struct fib_notifier_info *info);
229
230struct fib_table {
231	struct hlist_node	tb_hlist;
232	u32			tb_id;
233	int			tb_num_default;
234	struct rcu_head		rcu;
235	unsigned long 		*tb_data;
236	unsigned long		__data[0];
237};
238
239int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
240		     struct fib_result *res, int fib_flags);
241int fib_table_insert(struct net *, struct fib_table *, struct fib_config *);
242int fib_table_delete(struct net *, struct fib_table *, struct fib_config *);
243int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
244		   struct netlink_callback *cb);
245int fib_table_flush(struct net *net, struct fib_table *table);
246struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
247void fib_table_flush_external(struct fib_table *table);
248void fib_free_table(struct fib_table *tb);
249
250#ifndef CONFIG_IP_MULTIPLE_TABLES
251
252#define TABLE_LOCAL_INDEX	(RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
253#define TABLE_MAIN_INDEX	(RT_TABLE_MAIN  & (FIB_TABLE_HASHSZ - 1))
254
255static inline struct fib_table *fib_get_table(struct net *net, u32 id)
256{
257	struct hlist_node *tb_hlist;
258	struct hlist_head *ptr;
259
260	ptr = id == RT_TABLE_LOCAL ?
261		&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
262		&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
263
264	tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));
265
266	return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
267}
268
269static inline struct fib_table *fib_new_table(struct net *net, u32 id)
270{
271	return fib_get_table(net, id);
272}
273
274static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
275			     struct fib_result *res, unsigned int flags)
276{
277	struct fib_table *tb;
278	int err = -ENETUNREACH;
279
280	rcu_read_lock();
281
282	tb = fib_get_table(net, RT_TABLE_MAIN);
283	if (tb)
284		err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF);
285
286	if (err == -EAGAIN)
287		err = -ENETUNREACH;
288
289	rcu_read_unlock();
290
291	return err;
292}
293
294#else /* CONFIG_IP_MULTIPLE_TABLES */
295int __net_init fib4_rules_init(struct net *net);
296void __net_exit fib4_rules_exit(struct net *net);
297
298struct fib_table *fib_new_table(struct net *net, u32 id);
299struct fib_table *fib_get_table(struct net *net, u32 id);
300
301int __fib_lookup(struct net *net, struct flowi4 *flp,
302		 struct fib_result *res, unsigned int flags);
303
304static inline int fib_lookup(struct net *net, struct flowi4 *flp,
305			     struct fib_result *res, unsigned int flags)
306{
307	struct fib_table *tb;
308	int err = -ENETUNREACH;
309
310	flags |= FIB_LOOKUP_NOREF;
311	if (net->ipv4.fib_has_custom_rules)
312		return __fib_lookup(net, flp, res, flags);
313
314	rcu_read_lock();
315
316	res->tclassid = 0;
317
318	tb = rcu_dereference_rtnl(net->ipv4.fib_main);
319	if (tb)
320		err = fib_table_lookup(tb, flp, res, flags);
321
322	if (!err)
323		goto out;
324
325	tb = rcu_dereference_rtnl(net->ipv4.fib_default);
326	if (tb)
327		err = fib_table_lookup(tb, flp, res, flags);
328
329out:
330	if (err == -EAGAIN)
331		err = -ENETUNREACH;
332
333	rcu_read_unlock();
334
335	return err;
336}
337
338#endif /* CONFIG_IP_MULTIPLE_TABLES */
339
340/* Exported by fib_frontend.c */
341extern const struct nla_policy rtm_ipv4_policy[];
342void ip_fib_init(void);
343__be32 fib_compute_spec_dst(struct sk_buff *skb);
344int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
345			u8 tos, int oif, struct net_device *dev,
346			struct in_device *idev, u32 *itag);
347void fib_select_default(const struct flowi4 *flp, struct fib_result *res);
348#ifdef CONFIG_IP_ROUTE_CLASSID
349static inline int fib_num_tclassid_users(struct net *net)
350{
351	return net->ipv4.fib_num_tclassid_users;
352}
353#else
354static inline int fib_num_tclassid_users(struct net *net)
355{
356	return 0;
357}
358#endif
359int fib_unmerge(struct net *net);
 
360
361/* Exported by fib_semantics.c */
362int ip_fib_check_default(__be32 gw, struct net_device *dev);
363int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
364int fib_sync_down_addr(struct net_device *dev, __be32 local);
365int fib_sync_up(struct net_device *dev, unsigned int nh_flags);
366
367extern u32 fib_multipath_secret __read_mostly;
368
369static inline int fib_multipath_hash(__be32 saddr, __be32 daddr)
370{
371	return jhash_2words((__force u32)saddr, (__force u32)daddr,
372			    fib_multipath_secret) >> 1;
373}
374
375void fib_select_multipath(struct fib_result *res, int hash);
376void fib_select_path(struct net *net, struct fib_result *res,
377		     struct flowi4 *fl4, int mp_hash);
378
379/* Exported by fib_trie.c */
380void fib_trie_init(void);
381struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);
382
383static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
384{
385#ifdef CONFIG_IP_ROUTE_CLASSID
386#ifdef CONFIG_IP_MULTIPLE_TABLES
387	u32 rtag;
388#endif
389	*itag = FIB_RES_NH(*res).nh_tclassid<<16;
390#ifdef CONFIG_IP_MULTIPLE_TABLES
391	rtag = res->tclassid;
392	if (*itag == 0)
393		*itag = (rtag<<16);
394	*itag |= (rtag>>16);
395#endif
396#endif
397}
398
399void free_fib_info(struct fib_info *fi);
400
401static inline void fib_info_hold(struct fib_info *fi)
402{
403	atomic_inc(&fi->fib_clntref);
404}
405
406static inline void fib_info_put(struct fib_info *fi)
407{
408	if (atomic_dec_and_test(&fi->fib_clntref))
409		free_fib_info(fi);
410}
411
412#ifdef CONFIG_PROC_FS
413int __net_init fib_proc_init(struct net *net);
414void __net_exit fib_proc_exit(struct net *net);
415#else
416static inline int fib_proc_init(struct net *net)
417{
418	return 0;
419}
420static inline void fib_proc_exit(struct net *net)
421{
422}
423#endif
424
425#endif  /* _NET_FIB_H */