 345e9b5426
			
		
	
	
	345e9b5426
	
	
	
		
			
			This change is to start cleaning up some of the rcu_read_lock/unlock handling. I realized while reviewing the code there are several spots that I don't believe are being handled correctly or are masking warnings by locally calling rcu_read_lock/unlock instead of calling them at the correct level. A common example is a call to fib_get_table followed by fib_table_lookup. The rcu_read_lock/unlock ought to wrap both but there are several spots where they were not wrapped. Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
		
			
				
	
	
		
			346 lines
		
	
	
	
		
			8.5 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			346 lines
		
	
	
	
		
			8.5 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * INET		An implementation of the TCP/IP protocol suite for the LINUX
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|  *		operating system.  INET  is implemented using the  BSD Socket
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|  *		interface as the means of communication with the user level.
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|  *
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|  *		Definitions for the Forwarding Information Base.
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|  *
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|  * Authors:	A.N.Kuznetsov, <kuznet@ms2.inr.ac.ru>
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|  *
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|  *		This program is free software; you can redistribute it and/or
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|  *		modify it under the terms of the GNU General Public License
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|  *		as published by the Free Software Foundation; either version
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|  *		2 of the License, or (at your option) any later version.
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|  */
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| 
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| #ifndef _NET_IP_FIB_H
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| #define _NET_IP_FIB_H
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| 
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| #include <net/flow.h>
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| #include <linux/seq_file.h>
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| #include <linux/rcupdate.h>
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| #include <net/fib_rules.h>
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| #include <net/inetpeer.h>
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| #include <linux/percpu.h>
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| 
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| struct fib_config {
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| 	u8			fc_dst_len;
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| 	u8			fc_tos;
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| 	u8			fc_protocol;
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| 	u8			fc_scope;
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| 	u8			fc_type;
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| 	/* 3 bytes unused */
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| 	u32			fc_table;
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| 	__be32			fc_dst;
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| 	__be32			fc_gw;
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| 	int			fc_oif;
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| 	u32			fc_flags;
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| 	u32			fc_priority;
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| 	__be32			fc_prefsrc;
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| 	struct nlattr		*fc_mx;
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| 	struct rtnexthop	*fc_mp;
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| 	int			fc_mx_len;
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| 	int			fc_mp_len;
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| 	u32			fc_flow;
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| 	u32			fc_nlflags;
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| 	struct nl_info		fc_nlinfo;
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|  };
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| 
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| struct fib_info;
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| struct rtable;
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| 
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| struct fib_nh_exception {
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| 	struct fib_nh_exception __rcu	*fnhe_next;
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| 	int				fnhe_genid;
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| 	__be32				fnhe_daddr;
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| 	u32				fnhe_pmtu;
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| 	__be32				fnhe_gw;
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| 	unsigned long			fnhe_expires;
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| 	struct rtable __rcu		*fnhe_rth_input;
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| 	struct rtable __rcu		*fnhe_rth_output;
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| 	unsigned long			fnhe_stamp;
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| };
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| 
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| struct fnhe_hash_bucket {
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| 	struct fib_nh_exception __rcu	*chain;
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| };
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| 
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| #define FNHE_HASH_SHIFT		11
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| #define FNHE_HASH_SIZE		(1 << FNHE_HASH_SHIFT)
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| #define FNHE_RECLAIM_DEPTH	5
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| 
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| struct fib_nh {
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| 	struct net_device	*nh_dev;
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| 	struct hlist_node	nh_hash;
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| 	struct fib_info		*nh_parent;
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| 	unsigned int		nh_flags;
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| 	unsigned char		nh_scope;
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| #ifdef CONFIG_IP_ROUTE_MULTIPATH
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| 	int			nh_weight;
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| 	int			nh_power;
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| #endif
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| #ifdef CONFIG_IP_ROUTE_CLASSID
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| 	__u32			nh_tclassid;
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| #endif
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| 	int			nh_oif;
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| 	__be32			nh_gw;
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| 	__be32			nh_saddr;
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| 	int			nh_saddr_genid;
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| 	struct rtable __rcu * __percpu *nh_pcpu_rth_output;
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| 	struct rtable __rcu	*nh_rth_input;
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| 	struct fnhe_hash_bucket	__rcu *nh_exceptions;
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| };
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| 
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| /*
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|  * This structure contains data shared by many of routes.
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|  */
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| 
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| struct fib_info {
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| 	struct hlist_node	fib_hash;
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| 	struct hlist_node	fib_lhash;
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| 	struct net		*fib_net;
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| 	int			fib_treeref;
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| 	atomic_t		fib_clntref;
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| 	unsigned int		fib_flags;
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| 	unsigned char		fib_dead;
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| 	unsigned char		fib_protocol;
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| 	unsigned char		fib_scope;
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| 	unsigned char		fib_type;
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| 	__be32			fib_prefsrc;
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| 	u32			fib_priority;
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| 	u32			*fib_metrics;
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| #define fib_mtu fib_metrics[RTAX_MTU-1]
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| #define fib_window fib_metrics[RTAX_WINDOW-1]
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| #define fib_rtt fib_metrics[RTAX_RTT-1]
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| #define fib_advmss fib_metrics[RTAX_ADVMSS-1]
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| 	int			fib_nhs;
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| #ifdef CONFIG_IP_ROUTE_MULTIPATH
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| 	int			fib_power;
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| #endif
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| 	struct rcu_head		rcu;
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| 	struct fib_nh		fib_nh[0];
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| #define fib_dev		fib_nh[0].nh_dev
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| };
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| 
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| 
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| #ifdef CONFIG_IP_MULTIPLE_TABLES
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| struct fib_rule;
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| #endif
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| 
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| struct fib_table;
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| struct fib_result {
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| 	unsigned char	prefixlen;
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| 	unsigned char	nh_sel;
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| 	unsigned char	type;
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| 	unsigned char	scope;
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| 	u32		tclassid;
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| 	struct fib_info *fi;
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| 	struct fib_table *table;
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| 	struct list_head *fa_head;
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| };
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| 
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| struct fib_result_nl {
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| 	__be32		fl_addr;   /* To be looked up*/
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| 	u32		fl_mark;
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| 	unsigned char	fl_tos;
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| 	unsigned char   fl_scope;
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| 	unsigned char   tb_id_in;
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| 
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| 	unsigned char   tb_id;      /* Results */
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| 	unsigned char	prefixlen;
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| 	unsigned char	nh_sel;
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| 	unsigned char	type;
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| 	unsigned char	scope;
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| 	int             err;      
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| };
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| 
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| #ifdef CONFIG_IP_ROUTE_MULTIPATH
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| #define FIB_RES_NH(res)		((res).fi->fib_nh[(res).nh_sel])
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| #else /* CONFIG_IP_ROUTE_MULTIPATH */
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| #define FIB_RES_NH(res)		((res).fi->fib_nh[0])
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| #endif /* CONFIG_IP_ROUTE_MULTIPATH */
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| 
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| #ifdef CONFIG_IP_MULTIPLE_TABLES
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| #define FIB_TABLE_HASHSZ 256
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| #else
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| #define FIB_TABLE_HASHSZ 2
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| #endif
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| 
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| __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh);
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| 
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| #define FIB_RES_SADDR(net, res)				\
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| 	((FIB_RES_NH(res).nh_saddr_genid ==		\
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| 	  atomic_read(&(net)->ipv4.dev_addr_genid)) ?	\
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| 	 FIB_RES_NH(res).nh_saddr :			\
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| 	 fib_info_update_nh_saddr((net), &FIB_RES_NH(res)))
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| #define FIB_RES_GW(res)			(FIB_RES_NH(res).nh_gw)
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| #define FIB_RES_DEV(res)		(FIB_RES_NH(res).nh_dev)
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| #define FIB_RES_OIF(res)		(FIB_RES_NH(res).nh_oif)
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| 
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| #define FIB_RES_PREFSRC(net, res)	((res).fi->fib_prefsrc ? : \
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| 					 FIB_RES_SADDR(net, res))
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| 
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| struct fib_table {
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| 	struct hlist_node	tb_hlist;
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| 	u32			tb_id;
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| 	int			tb_default;
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| 	int			tb_num_default;
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| 	unsigned long		tb_data[0];
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| };
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| 
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| int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
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| 		     struct fib_result *res, int fib_flags);
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| int fib_table_insert(struct fib_table *, struct fib_config *);
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| int fib_table_delete(struct fib_table *, struct fib_config *);
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| int fib_table_dump(struct fib_table *table, struct sk_buff *skb,
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| 		   struct netlink_callback *cb);
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| int fib_table_flush(struct fib_table *table);
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| void fib_free_table(struct fib_table *tb);
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| 
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| 
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| 
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| #ifndef CONFIG_IP_MULTIPLE_TABLES
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| 
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| #define TABLE_LOCAL_INDEX	(RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
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| #define TABLE_MAIN_INDEX	(RT_TABLE_MAIN  & (FIB_TABLE_HASHSZ - 1))
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| 
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| static inline struct fib_table *fib_get_table(struct net *net, u32 id)
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| {
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| 	struct hlist_head *ptr;
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| 
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| 	ptr = id == RT_TABLE_LOCAL ?
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| 		&net->ipv4.fib_table_hash[TABLE_LOCAL_INDEX] :
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| 		&net->ipv4.fib_table_hash[TABLE_MAIN_INDEX];
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| 	return hlist_entry(ptr->first, struct fib_table, tb_hlist);
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| }
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| 
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| static inline struct fib_table *fib_new_table(struct net *net, u32 id)
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| {
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| 	return fib_get_table(net, id);
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| }
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| 
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| static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
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| 			     struct fib_result *res)
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| {
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| 	int err = -ENETUNREACH;
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| 
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| 	rcu_read_lock();
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| 
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| 	if (!fib_table_lookup(fib_get_table(net, RT_TABLE_LOCAL), flp, res,
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| 			      FIB_LOOKUP_NOREF) ||
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| 	    !fib_table_lookup(fib_get_table(net, RT_TABLE_MAIN), flp, res,
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| 			      FIB_LOOKUP_NOREF))
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| 		err = 0;
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| 
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| 	rcu_read_unlock();
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| 
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| 	return err;
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| }
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| 
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| #else /* CONFIG_IP_MULTIPLE_TABLES */
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| int __net_init fib4_rules_init(struct net *net);
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| void __net_exit fib4_rules_exit(struct net *net);
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| 
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| struct fib_table *fib_new_table(struct net *net, u32 id);
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| struct fib_table *fib_get_table(struct net *net, u32 id);
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| 
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| int __fib_lookup(struct net *net, struct flowi4 *flp, struct fib_result *res);
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| 
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| static inline int fib_lookup(struct net *net, struct flowi4 *flp,
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| 			     struct fib_result *res)
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| {
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| 	if (!net->ipv4.fib_has_custom_rules) {
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| 		int err = -ENETUNREACH;
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| 
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| 		rcu_read_lock();
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| 
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| 		res->tclassid = 0;
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| 		if ((net->ipv4.fib_local &&
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| 		     !fib_table_lookup(net->ipv4.fib_local, flp, res,
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| 				       FIB_LOOKUP_NOREF)) ||
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| 		    (net->ipv4.fib_main &&
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| 		     !fib_table_lookup(net->ipv4.fib_main, flp, res,
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| 				       FIB_LOOKUP_NOREF)) ||
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| 		    (net->ipv4.fib_default &&
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| 		     !fib_table_lookup(net->ipv4.fib_default, flp, res,
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| 				       FIB_LOOKUP_NOREF)))
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| 			err = 0;
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| 
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| 		rcu_read_unlock();
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| 
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| 		return err;
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| 	}
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| 	return __fib_lookup(net, flp, res);
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| }
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| 
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| #endif /* CONFIG_IP_MULTIPLE_TABLES */
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| 
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| /* Exported by fib_frontend.c */
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| extern const struct nla_policy rtm_ipv4_policy[];
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| void ip_fib_init(void);
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| __be32 fib_compute_spec_dst(struct sk_buff *skb);
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| int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
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| 			u8 tos, int oif, struct net_device *dev,
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| 			struct in_device *idev, u32 *itag);
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| void fib_select_default(struct fib_result *res);
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| #ifdef CONFIG_IP_ROUTE_CLASSID
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| static inline int fib_num_tclassid_users(struct net *net)
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| {
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| 	return net->ipv4.fib_num_tclassid_users;
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| }
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| #else
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| static inline int fib_num_tclassid_users(struct net *net)
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| {
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| 	return 0;
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| }
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| #endif
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| 
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| /* Exported by fib_semantics.c */
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| int ip_fib_check_default(__be32 gw, struct net_device *dev);
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| int fib_sync_down_dev(struct net_device *dev, int force);
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| int fib_sync_down_addr(struct net *net, __be32 local);
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| int fib_sync_up(struct net_device *dev);
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| void fib_select_multipath(struct fib_result *res);
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| 
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| /* Exported by fib_trie.c */
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| void fib_trie_init(void);
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| struct fib_table *fib_trie_table(u32 id);
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| 
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| static inline void fib_combine_itag(u32 *itag, const struct fib_result *res)
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| {
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| #ifdef CONFIG_IP_ROUTE_CLASSID
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| #ifdef CONFIG_IP_MULTIPLE_TABLES
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| 	u32 rtag;
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| #endif
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| 	*itag = FIB_RES_NH(*res).nh_tclassid<<16;
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| #ifdef CONFIG_IP_MULTIPLE_TABLES
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| 	rtag = res->tclassid;
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| 	if (*itag == 0)
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| 		*itag = (rtag<<16);
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| 	*itag |= (rtag>>16);
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| #endif
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| #endif
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| }
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| 
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| void free_fib_info(struct fib_info *fi);
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| 
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| static inline void fib_info_put(struct fib_info *fi)
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| {
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| 	if (atomic_dec_and_test(&fi->fib_clntref))
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| 		free_fib_info(fi);
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| }
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| 
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| #ifdef CONFIG_PROC_FS
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| int __net_init fib_proc_init(struct net *net);
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| void __net_exit fib_proc_exit(struct net *net);
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| #else
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| static inline int fib_proc_init(struct net *net)
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| {
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| 	return 0;
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| }
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| static inline void fib_proc_exit(struct net *net)
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| {
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| }
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| #endif
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| 
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| #endif  /* _NET_FIB_H */
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