text: /*
   *	Linux INET6 implementation 
   *
   *	Authors:
   *	Pedro Roque		<roque@di.fc.ul.pt>	
   *
   *	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 _IP6_FIB_H
  #define _IP6_FIB_H
  
  #ifdef __KERNEL__
  
  #include <linux/ipv6_route.h>
  #include <linux/rtnetlink.h>
  #include <linux/spinlock.h>
  #include <net/dst.h>
  #include <net/flow.h>
  #include <net/netlink.h>
  
  #ifdef CONFIG_IPV6_MULTIPLE_TABLES
  #define FIB6_TABLE_HASHSZ 256
  #else
  #define FIB6_TABLE_HASHSZ 1
  #endif
  
  struct rt6_info;
  
  struct fib6_config {
  	u32		fc_table;
  	u32		fc_metric;
  	int		fc_dst_len;
  	int		fc_src_len;
  	int		fc_ifindex;
  	u32		fc_flags;
  	u32		fc_protocol;
  
  	struct in6_addr	fc_dst;
  	struct in6_addr	fc_src;
  	struct in6_addr	fc_gateway;
  
  	unsigned long	fc_expires;
  	struct nlattr	*fc_mx;
  	int		fc_mx_len;
  
  	struct nl_info	fc_nlinfo;
  };
  
  struct fib6_node {
  	struct fib6_node	*parent;
  	struct fib6_node	*left;
  	struct fib6_node	*right;
  #ifdef CONFIG_IPV6_SUBTREES
  	struct fib6_node	*subtree;
  #endif
  	struct rt6_info		*leaf;
  
  	__u16			fn_bit;		/* bit key */
  	__u16			fn_flags;
  	__u32			fn_sernum;
  	struct rt6_info		*rr_ptr;
  };
  
  #ifndef CONFIG_IPV6_SUBTREES
  #define FIB6_SUBTREE(fn)	NULL
  #else
  #define FIB6_SUBTREE(fn)	((fn)->subtree)
  #endif
  
  /*
   *	routing information
   *
   */
  
  struct rt6key {
  	struct in6_addr	addr;
  	int		plen;
  };
  
  struct fib6_table;
  
  struct rt6_info {
  	struct dst_entry		dst;
  
  #define rt6i_dev			dst.dev
  #define rt6i_nexthop			dst.neighbour
  #define rt6i_expires			dst.expires
  
  	/*
  	 * Tail elements of dst_entry (__refcnt etc.)
  	 * and these elements (rarely used in hot path) are in
  	 * the same cache line.
  	 */
  	struct fib6_table		*rt6i_table;
  	struct fib6_node		*rt6i_node;
  
  	struct in6_addr			rt6i_gateway;
  
  	atomic_t			rt6i_ref;
  
  	/* These are in a separate cache line. */
  	struct rt6key			rt6i_dst ____cacheline_aligned_in_smp;
  	u32				rt6i_flags;
  	struct rt6key			rt6i_src;
  	u32				rt6i_metric;
  
  	struct inet6_dev		*rt6i_idev;
  
  #ifdef CONFIG_XFRM
  	u32				rt6i_flow_cache_genid;
  #endif
  	/* more non-fragment space at head required */
  	unsigned short			rt6i_nfheader_len;
  
  	u8				rt6i_protocol;
  };
  
  static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
  {
  	return ((struct rt6_info *)dst)->rt6i_idev;
  }
  
  struct fib6_walker_t {
  	struct list_head lh;
  	struct fib6_node *root, *node;
  	struct rt6_info *leaf;
  	unsigned char state;
  	unsigned char prune;
  	unsigned int skip;
  	unsigned int count;
  	int (*func)(struct fib6_walker_t *);
  	void *args;
  };
  
  struct rt6_statistics {
  	__u32		fib_nodes;
  	__u32		fib_route_nodes;
  	__u32		fib_rt_alloc;		/* permanent routes	*/
  	__u32		fib_rt_entries;		/* rt entries in table	*/
  	__u32		fib_rt_cache;		/* cache routes		*/
  	__u32		fib_discarded_routes;
  };
  
  #define RTN_TL_ROOT	0x0001
  #define RTN_ROOT	0x0002		/* tree root node		*/
  #define RTN_RTINFO	0x0004		/* node with valid routing info	*/
  
  /*
   *	priority levels (or metrics)
   *
   */
  
  
  struct fib6_table {
  	struct hlist_node	tb6_hlist;
  	u32			tb6_id;
  	rwlock_t		tb6_lock;
  	struct fib6_node	tb6_root;
  };
  
  #define RT6_TABLE_UNSPEC	RT_TABLE_UNSPEC
  #define RT6_TABLE_MAIN		RT_TABLE_MAIN
  #define RT6_TABLE_DFLT		RT6_TABLE_MAIN
  #define RT6_TABLE_INFO		RT6_TABLE_MAIN
  #define RT6_TABLE_PREFIX	RT6_TABLE_MAIN
  
  #ifdef CONFIG_IPV6_MULTIPLE_TABLES
  #define FIB6_TABLE_MIN		1
  #define FIB6_TABLE_MAX		RT_TABLE_MAX
  #define RT6_TABLE_LOCAL		RT_TABLE_LOCAL
  #else
  #define FIB6_TABLE_MIN		RT_TABLE_MAIN
  #define FIB6_TABLE_MAX		FIB6_TABLE_MIN
  #define RT6_TABLE_LOCAL		RT6_TABLE_MAIN
  #endif
  
  typedef struct rt6_info *(*pol_lookup_t)(struct net *,
  					 struct fib6_table *,
  					 struct flowi *, int);
  
  /*
   *	exported functions
   */
  
  extern struct fib6_table        *fib6_get_table(struct net *net, u32 id);
  extern struct fib6_table        *fib6_new_table(struct net *net, u32 id);
  extern struct dst_entry         *fib6_rule_lookup(struct net *net,
  						  struct flowi *fl, int flags,
  						  pol_lookup_t lookup);
  
  extern struct fib6_node		*fib6_lookup(struct fib6_node *root,
  					     struct in6_addr *daddr,
  					     struct in6_addr *saddr);
  
  struct fib6_node		*fib6_locate(struct fib6_node *root,
  					     struct in6_addr *daddr, int dst_len,
  					     struct in6_addr *saddr, int src_len);
  
  extern void			fib6_clean_all(struct net *net,
  					       int (*func)(struct rt6_info *, void *arg),
  					       int prune, void *arg);
  
  extern int			fib6_add(struct fib6_node *root,
  					 struct rt6_info *rt,
  					 struct nl_info *info);
  
  extern int			fib6_del(struct rt6_info *rt,
  					 struct nl_info *info);
  
  extern void			inet6_rt_notify(int event, struct rt6_info *rt,
  						struct nl_info *info);
  
  extern void			fib6_run_gc(unsigned long expires,
  					    struct net *net);
  
  extern void			fib6_gc_cleanup(void);
  
  extern int			fib6_init(void);
  
  #ifdef CONFIG_IPV6_MULTIPLE_TABLES
  extern int			fib6_rules_init(void);
  extern void			fib6_rules_cleanup(void);
  #else
  static inline int               fib6_rules_init(void)
  {
  	return 0;
  }
  static inline void              fib6_rules_cleanup(void)
  {
  	return ;
  }
  #endif
  #endif
  #endif
  