include/net/ip_fib.h - kernel/msm-4.19 - Gitiles

 /*
  * INET		An implementation of the TCP/IP protocol suite for the LINUX
  *		operating system.  INET  is implemented using the  BSD Socket
  *		interface as the means of communication with the user level.
  *
  *		Definitions for the Forwarding Information Base.
  *
  * Authors:	A.N.Kuznetsov, <kuznet@ms2.inr.ac.ru>
  *
  *		This program is free software; you can redistribute it and/or
  *		modify it under the terms of the GNU General Public License
  *		as published by the Free Software Foundation; either version
  *		2 of the License, or (at your option) any later version.
  */

 #ifndef _NET_IP_FIB_H
 #define _NET_IP_FIB_H

 #include <net/flow.h>
 #include <linux/seq_file.h>
 #include <linux/rcupdate.h>
 #include <net/fib_rules.h>
 #include <net/inetpeer.h>
 #include <linux/percpu.h>
 #include <linux/notifier.h>

 struct fib_config {
 	u8			fc_dst_len;
 	u8			fc_tos;
 	u8			fc_protocol;
 	u8			fc_scope;
 	u8			fc_type;
 	/* 3 bytes unused */
 	u32			fc_table;
 	__be32			fc_dst;
 	__be32			fc_gw;
 	int			fc_oif;
 	u32			fc_flags;
 	u32			fc_priority;
 	__be32			fc_prefsrc;
 	struct nlattr		*fc_mx;
 	struct rtnexthop	*fc_mp;
 	int			fc_mx_len;
 	int			fc_mp_len;
 	u32			fc_flow;
 	u32			fc_nlflags;
 	struct nl_info		fc_nlinfo;
 	struct nlattr		*fc_encap;
 	u16			fc_encap_type;
 };

 struct fib_info;
 struct rtable;

 struct fib_nh_exception {
 	struct fib_nh_exception __rcu	*fnhe_next;
 	int				fnhe_genid;
 	__be32				fnhe_daddr;
 	u32				fnhe_pmtu;
 	__be32				fnhe_gw;
 	unsigned long			fnhe_expires;
 	struct rtable __rcu		*fnhe_rth_input;
 	struct rtable __rcu		*fnhe_rth_output;
 	unsigned long			fnhe_stamp;
 	struct rcu_head			rcu;
 };

 struct fnhe_hash_bucket {
 	struct fib_nh_exception __rcu	*chain;
 };

 #define FNHE_HASH_SHIFT		11
 #define FNHE_HASH_SIZE		(1 << FNHE_HASH_SHIFT)
 #define FNHE_RECLAIM_DEPTH	5

 struct fib_nh {
 	struct net_device	*nh_dev;
 	struct hlist_node	nh_hash;
 	struct fib_info		*nh_parent;
 	unsigned int		nh_flags;
 	unsigned char		nh_scope;
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 	int			nh_weight;
 	atomic_t		nh_upper_bound;
 #endif
 #ifdef CONFIG_IP_ROUTE_CLASSID
 	__u32			nh_tclassid;
 #endif
 	int			nh_oif;
 	__be32			nh_gw;
 	__be32			nh_saddr;
 	int			nh_saddr_genid;
 	struct rtable __rcu * __percpu *nh_pcpu_rth_output;
 	struct rtable __rcu	*nh_rth_input;
 	struct fnhe_hash_bucket	__rcu *nh_exceptions;
 	struct lwtunnel_state	*nh_lwtstate;
 };

 /*
  * This structure contains data shared by many of routes.
  */

 struct fib_info {
 	struct hlist_node	fib_hash;
 	struct hlist_node	fib_lhash;
 	struct net		*fib_net;
 	int			fib_treeref;
 	atomic_t		fib_clntref;
 	unsigned int		fib_flags;
 	unsigned char		fib_dead;
 	unsigned char		fib_protocol;
 	unsigned char		fib_scope;
 	unsigned char		fib_type;
 	__be32			fib_prefsrc;
 	u32			fib_tb_id;
 	u32			fib_priority;
 	u32			*fib_metrics;
 #define fib_mtu fib_metrics[RTAX_MTU-1]
 #define fib_window fib_metrics[RTAX_WINDOW-1]
 #define fib_rtt fib_metrics[RTAX_RTT-1]
 #define fib_advmss fib_metrics[RTAX_ADVMSS-1]
 	int			fib_nhs;
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 	int			fib_weight;
 #endif
 	unsigned int		fib_offload_cnt;
 	struct rcu_head		rcu;
 	struct fib_nh		fib_nh[0];
 #define fib_dev		fib_nh[0].nh_dev
 };


 #ifdef CONFIG_IP_MULTIPLE_TABLES
 struct fib_rule;
 #endif

 struct fib_table;
 struct fib_result {
 	unsigned char	prefixlen;
 	unsigned char	nh_sel;
 	unsigned char	type;
 	unsigned char	scope;
 	u32		tclassid;
 	struct fib_info *fi;
 	struct fib_table *table;
 	struct hlist_head *fa_head;
 };

 struct fib_result_nl {
 	__be32		fl_addr;   /* To be looked up*/
 	u32		fl_mark;
 	unsigned char	fl_tos;
 	unsigned char   fl_scope;
 	unsigned char   tb_id_in;

 	unsigned char   tb_id;      /* Results */
 	unsigned char	prefixlen;
 	unsigned char	nh_sel;
 	unsigned char	type;
 	unsigned char	scope;
 	int             err;
 };

 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 #define FIB_RES_NH(res)		((res).fi->fib_nh[(res).nh_sel])
 #else /* CONFIG_IP_ROUTE_MULTIPATH */
 #define FIB_RES_NH(res)		((res).fi->fib_nh[0])
 #endif /* CONFIG_IP_ROUTE_MULTIPATH */

 #ifdef CONFIG_IP_MULTIPLE_TABLES
 #define FIB_TABLE_HASHSZ 256
 #else
 #define FIB_TABLE_HASHSZ 2
 #endif

 __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);

 static inline void fib_info_offload_inc(struct fib_info *fi)
 {
 	fi->fib_offload_cnt++;
 	fi->fib_flags |= RTNH_F_OFFLOAD;
 }

 static inline void fib_info_offload_dec(struct fib_info *fi)
 {
 	if (--fi->fib_offload_cnt == 0)
 		fi->fib_flags &= ~RTNH_F_OFFLOAD;
 }

 #define FIB_RES_SADDR(net, res)				\
 	((FIB_RES_NH(res).nh_saddr_genid ==		\
 	  atomic_read(&(net)->ipv4.dev_addr_genid)) ?	\
 	 FIB_RES_NH(res).nh_saddr :			\
 	 fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
 #define FIB_RES_GW(res)			(FIB_RES_NH(res).nh_gw)
 #define FIB_RES_DEV(res)		(FIB_RES_NH(res).nh_dev)
 #define FIB_RES_OIF(res)		(FIB_RES_NH(res).nh_oif)

 #define FIB_RES_PREFSRC(net, res)	((res).fi->fib_prefsrc ? : \
 					 FIB_RES_SADDR(net, res))

 struct fib_notifier_info {
 	struct net *net;
 };

 struct fib_entry_notifier_info {
 	struct fib_notifier_info info; /* must be first */
 	u32 dst;
 	int dst_len;
 	struct fib_info *fi;
 	u8 tos;
 	u8 type;
 	u32 tb_id;
 	u32 nlflags;
 };

 enum fib_event_type {
 	FIB_EVENT_ENTRY_ADD,
 	FIB_EVENT_ENTRY_DEL,
 	FIB_EVENT_RULE_ADD,
 	FIB_EVENT_RULE_DEL,
 };

 int register_fib_notifier(struct notifier_block *nb);
 int unregister_fib_notifier(struct notifier_block *nb);
 int call_fib_notifiers(struct net *net, enum fib_event_type event_type,
 		       struct fib_notifier_info *info);

 struct fib_table {
 	struct hlist_node	tb_hlist;
 	u32			tb_id;
 	int			tb_num_default;
 	struct rcu_head		rcu;
 	unsigned long 		*tb_data;
 	unsigned long		__data[0];
 };

 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
 		     struct fib_result *res, int fib_flags);
 int fib_table_insert(struct net *, struct fib_table *, struct fib_config *);
 int fib_table_delete(struct net *, struct fib_table *, struct fib_config *);
 int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
 		   struct netlink_callback *cb);
 int fib_table_flush(struct net *net, struct fib_table *table);
 struct fib_table *fib_trie_unmerge(struct fib_table *main_tb);
 void fib_free_table(struct fib_table *tb);

 #ifndef CONFIG_IP_MULTIPLE_TABLES

 #define TABLE_LOCAL_INDEX	(RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
 #define TABLE_MAIN_INDEX	(RT_TABLE_MAIN  & (FIB_TABLE_HASHSZ - 1))

 static inline struct fib_table *fib_get_table(struct net *net, u32 id)
 {
 	struct hlist_node *tb_hlist;
 	struct hlist_head *ptr;

 	ptr = id == RT_TABLE_LOCAL ?
 		&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
 		&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];

 	tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));

 	return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
 }

 static inline struct fib_table *fib_new_table(struct net *net, u32 id)
 {
 	return fib_get_table(net, id);
 }

 static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
 			     struct fib_result *res, unsigned int flags)
 {
 	struct fib_table *tb;
 	int err = -ENETUNREACH;

 	rcu_read_lock();

 	tb = fib_get_table(net, RT_TABLE_MAIN);
 	if (tb)
 		err = fib_table_lookup(tb, flp, res, flags | FIB_LOOKUP_NOREF);

 	if (err == -EAGAIN)
 		err = -ENETUNREACH;

 	rcu_read_unlock();

 	return err;
 }

 #else /* CONFIG_IP_MULTIPLE_TABLES */
 int __net_init fib4_rules_init(struct net *net);
 void __net_exit fib4_rules_exit(struct net *net);

 struct fib_table *fib_new_table(struct net *net, u32 id);
 struct fib_table *fib_get_table(struct net *net, u32 id);

 int __fib_lookup(struct net *net, struct flowi4 *flp,
 		 struct fib_result *res, unsigned int flags);

 static inline int fib_lookup(struct net *net, struct flowi4 *flp,
 			     struct fib_result *res, unsigned int flags)
 {
 	struct fib_table *tb;
 	int err = -ENETUNREACH;

 	flags |= FIB_LOOKUP_NOREF;
 	if (net->ipv4.fib_has_custom_rules)
 		return __fib_lookup(net, flp, res, flags);

 	rcu_read_lock();

 	res->tclassid = 0;

 	tb = rcu_dereference_rtnl(net->ipv4.fib_main);
 	if (tb)
 		err = fib_table_lookup(tb, flp, res, flags);

 	if (!err)
 		goto out;

 	tb = rcu_dereference_rtnl(net->ipv4.fib_default);
 	if (tb)
 		err = fib_table_lookup(tb, flp, res, flags);

 out:
 	if (err == -EAGAIN)
 		err = -ENETUNREACH;

 	rcu_read_unlock();

 	return err;
 }

 #endif /* CONFIG_IP_MULTIPLE_TABLES */

 /* Exported by fib_frontend.c */
 extern const struct nla_policy rtm_ipv4_policy[];
 void ip_fib_init(void);
 __be32 fib_compute_spec_dst(struct sk_buff *skb);
 int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 			u8 tos, int oif, struct net_device *dev,
 			struct in_device *idev, u32 *itag);
 void fib_select_default(const struct flowi4 *flp, struct fib_result *res);
 #ifdef CONFIG_IP_ROUTE_CLASSID
 static inline int fib_num_tclassid_users(struct net *net)
 {
 	return net->ipv4.fib_num_tclassid_users;
 }
 #else
 static inline int fib_num_tclassid_users(struct net *net)
 {
 	return 0;
 }
 #endif
 int fib_unmerge(struct net *net);

 /* Exported by fib_semantics.c */
 int ip_fib_check_default(__be32 gw, struct net_device *dev);
 int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
 int fib_sync_down_addr(struct net_device *dev, __be32 local);
 int fib_sync_up(struct net_device *dev, unsigned int nh_flags);

 extern u32 fib_multipath_secret __read_mostly;

 static inline int fib_multipath_hash(__be32 saddr, __be32 daddr)
 {
 	return jhash_2words((__force u32)saddr, (__force u32)daddr,
 			    fib_multipath_secret) >> 1;
 }

 void fib_select_multipath(struct fib_result *res, int hash);
 void fib_select_path(struct net *net, struct fib_result *res,
 		     struct flowi4 *fl4, int mp_hash);

 /* Exported by fib_trie.c */
 void fib_trie_init(void);
 struct fib_table *fib_trie_table(u32 id, struct fib_table *alias);

 static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
 {
 #ifdef CONFIG_IP_ROUTE_CLASSID
 #ifdef CONFIG_IP_MULTIPLE_TABLES
 	u32 rtag;
 #endif
 	*itag = FIB_RES_NH(*res).nh_tclassid<<16;
 #ifdef CONFIG_IP_MULTIPLE_TABLES
 	rtag = res->tclassid;
 	if (*itag == 0)
 		*itag = (rtag<<16);
 	*itag |= (rtag>>16);
 #endif
 #endif
 }

 void free_fib_info(struct fib_info *fi);

 static inline void fib_info_put(struct fib_info *fi)
 {
 	if (atomic_dec_and_test(&fi->fib_clntref))
 		free_fib_info(fi);
 }

 #ifdef CONFIG_PROC_FS
 int __net_init fib_proc_init(struct net *net);
 void __net_exit fib_proc_exit(struct net *net);
 #else
 static inline int fib_proc_init(struct net *net)
 {
 	return 0;
 }
 static inline void fib_proc_exit(struct net *net)
 {
 }
 #endif

 #endif  /* _NET_FIB_H */
	/*
	* INET An implementation of the TCP/IP protocol suite for the LINUX
	* operating system. INET is implemented using the BSD Socket
	* interface as the means of communication with the user level.
	*
	* Definitions for the Forwarding Information Base.
	*
	* Authors: A.N.Kuznetsov, <kuznet@ms2.inr.ac.ru>
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version
	* 2 of the License, or (at your option) any later version.
	*/

	#ifndef _NET_IP_FIB_H
	#define _NET_IP_FIB_H

	#include <net/flow.h>
	#include <linux/seq_file.h>
	#include <linux/rcupdate.h>
	#include <net/fib_rules.h>
	#include <net/inetpeer.h>
	#include <linux/percpu.h>
	#include <linux/notifier.h>

	struct fib_config {
	u8 fc_dst_len;
	u8 fc_tos;
	u8 fc_protocol;
	u8 fc_scope;
	u8 fc_type;
	/* 3 bytes unused */
	u32 fc_table;
	__be32 fc_dst;
	__be32 fc_gw;
	int fc_oif;
	u32 fc_flags;
	u32 fc_priority;
	__be32 fc_prefsrc;
	struct nlattr *fc_mx;
	struct rtnexthop *fc_mp;
	int fc_mx_len;
	int fc_mp_len;
	u32 fc_flow;
	u32 fc_nlflags;
	struct nl_info fc_nlinfo;
	struct nlattr *fc_encap;
	u16 fc_encap_type;
	};

	struct fib_info;
	struct rtable;

	struct fib_nh_exception {
	struct fib_nh_exception __rcu *fnhe_next;
	int fnhe_genid;
	__be32 fnhe_daddr;
	u32 fnhe_pmtu;
	__be32 fnhe_gw;
	unsigned long fnhe_expires;
	struct rtable __rcu *fnhe_rth_input;
	struct rtable __rcu *fnhe_rth_output;
	unsigned long fnhe_stamp;
	struct rcu_head rcu;
	};

	struct fnhe_hash_bucket {
	struct fib_nh_exception __rcu *chain;
	};

	#define FNHE_HASH_SHIFT 11
	#define FNHE_HASH_SIZE (1 << FNHE_HASH_SHIFT)
	#define FNHE_RECLAIM_DEPTH 5

	struct fib_nh {
	struct net_device *nh_dev;
	struct hlist_node nh_hash;
	struct fib_info *nh_parent;
	unsigned int nh_flags;
	unsigned char nh_scope;
	#ifdef CONFIG_IP_ROUTE_MULTIPATH
	int nh_weight;
	atomic_t nh_upper_bound;
	#endif
	#ifdef CONFIG_IP_ROUTE_CLASSID
	__u32 nh_tclassid;
	#endif
	int nh_oif;
	__be32 nh_gw;
	__be32 nh_saddr;
	int nh_saddr_genid;
	struct rtable __rcu * __percpu *nh_pcpu_rth_output;
	struct rtable __rcu *nh_rth_input;
	struct fnhe_hash_bucket __rcu *nh_exceptions;
	struct lwtunnel_state *nh_lwtstate;
	};

	/*
	* This structure contains data shared by many of routes.
	*/

	struct fib_info {
	struct hlist_node fib_hash;
	struct hlist_node fib_lhash;
	struct net *fib_net;
	int fib_treeref;
	atomic_t fib_clntref;
	unsigned int fib_flags;
	unsigned char fib_dead;
	unsigned char fib_protocol;
	unsigned char fib_scope;
	unsigned char fib_type;
	__be32 fib_prefsrc;
	u32 fib_tb_id;
	u32 fib_priority;
	u32 *fib_metrics;
	#define fib_mtu fib_metrics[RTAX_MTU-1]
	#define fib_window fib_metrics[RTAX_WINDOW-1]
	#define fib_rtt fib_metrics[RTAX_RTT-1]
	#define fib_advmss fib_metrics[RTAX_ADVMSS-1]
	int fib_nhs;
	#ifdef CONFIG_IP_ROUTE_MULTIPATH
	int fib_weight;
	#endif
	unsigned int fib_offload_cnt;
	struct rcu_head rcu;
	struct fib_nh fib_nh[0];
	#define fib_dev fib_nh[0].nh_dev
	};


	#ifdef CONFIG_IP_MULTIPLE_TABLES
	struct fib_rule;
	#endif

	struct fib_table;
	struct fib_result {
	unsigned char prefixlen;
	unsigned char nh_sel;
	unsigned char type;
	unsigned char scope;
	u32 tclassid;
	struct fib_info *fi;
	struct fib_table *table;
	struct hlist_head *fa_head;
	};

	struct fib_result_nl {
	__be32 fl_addr; /* To be looked up*/
	u32 fl_mark;
	unsigned char fl_tos;
	unsigned char fl_scope;
	unsigned char tb_id_in;

	unsigned char tb_id; /* Results */
	unsigned char prefixlen;
	unsigned char nh_sel;
	unsigned char type;
	unsigned char scope;
	int err;
	};

	#ifdef CONFIG_IP_ROUTE_MULTIPATH
	#define FIB_RES_NH(res) ((res).fi->fib_nh[(res).nh_sel])
	#else /* CONFIG_IP_ROUTE_MULTIPATH */
	#define FIB_RES_NH(res) ((res).fi->fib_nh[0])
	#endif /* CONFIG_IP_ROUTE_MULTIPATH */

	#ifdef CONFIG_IP_MULTIPLE_TABLES
	#define FIB_TABLE_HASHSZ 256
	#else
	#define FIB_TABLE_HASHSZ 2
	#endif

	__be32 fib_info_update_nh_saddr(struct net net, struct fib_nh nh);

	static inline void fib_info_offload_inc(struct fib_info *fi)
	{
	fi->fib_offload_cnt++;
	fi->fib_flags \|= RTNH_F_OFFLOAD;
	}

	static inline void fib_info_offload_dec(struct fib_info *fi)
	{
	if (--fi->fib_offload_cnt == 0)
	fi->fib_flags &= ~RTNH_F_OFFLOAD;
	}

	#define FIB_RES_SADDR(net, res) \
	((FIB_RES_NH(res).nh_saddr_genid == \
	atomic_read(&(net)->ipv4.dev_addr_genid)) ? \
	FIB_RES_NH(res).nh_saddr : \
	fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
	#define FIB_RES_GW(res) (FIB_RES_NH(res).nh_gw)
	#define FIB_RES_DEV(res) (FIB_RES_NH(res).nh_dev)
	#define FIB_RES_OIF(res) (FIB_RES_NH(res).nh_oif)

	#define FIB_RES_PREFSRC(net, res) ((res).fi->fib_prefsrc ? : \
	FIB_RES_SADDR(net, res))

	struct fib_notifier_info {
	struct net *net;
	};

	struct fib_entry_notifier_info {
	struct fib_notifier_info info; /* must be first */
	u32 dst;
	int dst_len;
	struct fib_info *fi;
	u8 tos;
	u8 type;
	u32 tb_id;
	u32 nlflags;
	};

	enum fib_event_type {
	FIB_EVENT_ENTRY_ADD,
	FIB_EVENT_ENTRY_DEL,
	FIB_EVENT_RULE_ADD,
	FIB_EVENT_RULE_DEL,
	};

	int register_fib_notifier(struct notifier_block *nb);
	int unregister_fib_notifier(struct notifier_block *nb);
	int call_fib_notifiers(struct net *net, enum fib_event_type event_type,
	struct fib_notifier_info *info);

	struct fib_table {
	struct hlist_node tb_hlist;
	u32 tb_id;
	int tb_num_default;
	struct rcu_head rcu;
	unsigned long *tb_data;
	unsigned long __data[0];
	};

	int fib_table_lookup(struct fib_table tb, const struct flowi4 flp,
	struct fib_result *res, int fib_flags);
	int fib_table_insert(struct net , struct fib_table , struct fib_config *);
	int fib_table_delete(struct net , struct fib_table , struct fib_config *);
	int fib_table_dump(struct fib_table table, struct sk_buff skb,
	struct netlink_callback *cb);
	int fib_table_flush(struct net net, struct fib_table table);
	struct fib_table fib_trie_unmerge(struct fib_table main_tb);
	void fib_free_table(struct fib_table *tb);

	#ifndef CONFIG_IP_MULTIPLE_TABLES

	#define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
	#define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1))

	static inline struct fib_table fib_get_table(struct net net, u32 id)
	{
	struct hlist_node *tb_hlist;
	struct hlist_head *ptr;

	ptr = id == RT_TABLE_LOCAL ?
	&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
	&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];

	tb_hlist = rcu_dereference_rtnl(hlist_first_rcu(ptr));

	return hlist_entry(tb_hlist, struct fib_table, tb_hlist);
	}

	static inline struct fib_table fib_new_table(struct net net, u32 id)
	{
	return fib_get_table(net, id);
	}

	static inline int fib_lookup(struct net net, const struct flowi4 flp,
	struct fib_result *res, unsigned int flags)
	{
	struct fib_table *tb;
	int err = -ENETUNREACH;

	rcu_read_lock();

	tb = fib_get_table(net, RT_TABLE_MAIN);
	if (tb)
	err = fib_table_lookup(tb, flp, res, flags \| FIB_LOOKUP_NOREF);

	if (err == -EAGAIN)
	err = -ENETUNREACH;

	rcu_read_unlock();

	return err;
	}

	#else /* CONFIG_IP_MULTIPLE_TABLES */
	int __net_init fib4_rules_init(struct net *net);
	void __net_exit fib4_rules_exit(struct net *net);

	struct fib_table fib_new_table(struct net net, u32 id);
	struct fib_table fib_get_table(struct net net, u32 id);

	int __fib_lookup(struct net net, struct flowi4 flp,
	struct fib_result *res, unsigned int flags);

	static inline int fib_lookup(struct net net, struct flowi4 flp,
	struct fib_result *res, unsigned int flags)
	{
	struct fib_table *tb;
	int err = -ENETUNREACH;

	flags \|= FIB_LOOKUP_NOREF;
	if (net->ipv4.fib_has_custom_rules)
	return __fib_lookup(net, flp, res, flags);

	rcu_read_lock();

	res->tclassid = 0;

	tb = rcu_dereference_rtnl(net->ipv4.fib_main);
	if (tb)
	err = fib_table_lookup(tb, flp, res, flags);

	if (!err)
	goto out;

	tb = rcu_dereference_rtnl(net->ipv4.fib_default);
	if (tb)
	err = fib_table_lookup(tb, flp, res, flags);

	out:
	if (err == -EAGAIN)
	err = -ENETUNREACH;

	rcu_read_unlock();

	return err;
	}

	#endif /* CONFIG_IP_MULTIPLE_TABLES */

	/* Exported by fib_frontend.c */
	extern const struct nla_policy rtm_ipv4_policy[];
	void ip_fib_init(void);
	__be32 fib_compute_spec_dst(struct sk_buff *skb);
	int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
	u8 tos, int oif, struct net_device *dev,
	struct in_device idev, u32 itag);
	void fib_select_default(const struct flowi4 flp, struct fib_result res);
	#ifdef CONFIG_IP_ROUTE_CLASSID
	static inline int fib_num_tclassid_users(struct net *net)
	{
	return net->ipv4.fib_num_tclassid_users;
	}
	#else
	static inline int fib_num_tclassid_users(struct net *net)
	{
	return 0;
	}
	#endif
	int fib_unmerge(struct net *net);

	/* Exported by fib_semantics.c */
	int ip_fib_check_default(__be32 gw, struct net_device *dev);
	int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool force);
	int fib_sync_down_addr(struct net_device *dev, __be32 local);
	int fib_sync_up(struct net_device *dev, unsigned int nh_flags);

	extern u32 fib_multipath_secret __read_mostly;

	static inline int fib_multipath_hash(__be32 saddr, __be32 daddr)
	{
	return jhash_2words((__force u32)saddr, (__force u32)daddr,
	fib_multipath_secret) >> 1;
	}

	void fib_select_multipath(struct fib_result *res, int hash);
	void fib_select_path(struct net net, struct fib_result res,
	struct flowi4 *fl4, int mp_hash);

	/* Exported by fib_trie.c */
	void fib_trie_init(void);
	struct fib_table fib_trie_table(u32 id, struct fib_table alias);

	static inline void fib_combine_itag(u32 itag, const struct fib_result res)
	{
	#ifdef CONFIG_IP_ROUTE_CLASSID
	#ifdef CONFIG_IP_MULTIPLE_TABLES
	u32 rtag;
	#endif
	itag = FIB_RES_NH(res).nh_tclassid<<16;
	#ifdef CONFIG_IP_MULTIPLE_TABLES
	rtag = res->tclassid;
	if (*itag == 0)
	*itag = (rtag<<16);
	*itag \|= (rtag>>16);
	#endif
	#endif
	}

	void free_fib_info(struct fib_info *fi);

	static inline void fib_info_put(struct fib_info *fi)
	{
	if (atomic_dec_and_test(&fi->fib_clntref))
	free_fib_info(fi);
	}

	#ifdef CONFIG_PROC_FS
	int __net_init fib_proc_init(struct net *net);
	void __net_exit fib_proc_exit(struct net *net);
	#else
	static inline int fib_proc_init(struct net *net)
	{
	return 0;
	}
	static inline void fib_proc_exit(struct net *net)
	{
	}
	#endif

	#endif /* _NET_FIB_H */