/*
   *	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

  #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>

  #include <net/inetpeer.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;

  	u32		fc_type;	/* only 8 bits are used */

  
  	struct in6_addr	fc_dst;
  	struct in6_addr	fc_src;

  	struct in6_addr	fc_prefsrc;

  	struct in6_addr	fc_gateway;
  
  	unsigned long	fc_expires;
  	struct nlattr	*fc_mx;
  	int		fc_mx_len;

  	int		fc_mp_len;
  	struct nlattr	*fc_mp;

  
  	struct nl_info	fc_nlinfo;

  	struct nlattr	*fc_encap;
  	u16		fc_encap_type;

  };

  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;

  	int			fn_sernum;

  	struct rt6_info		*rr_ptr;

  };

  #ifndef CONFIG_IPV6_SUBTREES
  #define FIB6_SUBTREE(fn)	NULL
  #else
  #define FIB6_SUBTREE(fn)	((fn)->subtree)
  #endif

  struct mx6_config {
  	const u32 *mx;
  	DECLARE_BITMAP(mx_valid, RTAX_MAX);
  };

  /*
   *	routing information
   *
   */

  struct rt6key {

  	struct in6_addr	addr;
  	int		plen;
  };

  struct fib6_table;

  struct rt6_info {

  	struct dst_entry		dst;

  	/*
  	 * 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;

  	/* Multipath routes:
  	 * siblings is a list of rt6_info that have the the same metric/weight,
  	 * destination, but not the same gateway. nsiblings is just a cache
  	 * to speed up lookup.
  	 */
  	struct list_head		rt6i_siblings;
  	unsigned int			rt6i_nsiblings;

  	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;

  	struct rt6key			rt6i_prefsrc;

  	struct list_head		rt6i_uncached;
  	struct uncached_list		*rt6i_uncached_list;

  	struct inet6_dev		*rt6i_idev;

  	struct rt6_info * __percpu	*rt6i_pcpu;

  	u32				rt6i_metric;

  	u32				rt6i_pmtu;

  	/* 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;
  }

  static inline void rt6_clean_expires(struct rt6_info *rt)
  {

  	rt->rt6i_flags &= ~RTF_EXPIRES;

  	rt->dst.expires = 0;

  }
  
  static inline void rt6_set_expires(struct rt6_info *rt, unsigned long expires)
  {

  	rt->dst.expires = expires;

  	rt->rt6i_flags |= RTF_EXPIRES;

  }

  static inline void rt6_update_expires(struct rt6_info *rt0, int timeout)

  {

  	struct rt6_info *rt;
  
  	for (rt = rt0; rt && !(rt->rt6i_flags & RTF_EXPIRES);
  	     rt = (struct rt6_info *)rt->dst.from);
  	if (rt && rt != rt0)
  		rt0->dst.expires = rt->dst.expires;
  
  	dst_set_expires(&rt0->dst, timeout);
  	rt0->rt6i_flags |= RTF_EXPIRES;

  }

  
  static inline u32 rt6_get_cookie(const struct rt6_info *rt)
  {

  	if (rt->rt6i_flags & RTF_PCPU ||
  	    (unlikely(rt->dst.flags & DST_NOCACHE) && rt->dst.from))

  		rt = (struct rt6_info *)(rt->dst.from);

  	return rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
  }

  static inline void ip6_rt_put(struct rt6_info *rt)
  {
  	/* dst_release() accepts a NULL parameter.
  	 * We rely on dst being first structure in struct rt6_info
  	 */
  	BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
  	dst_release(&rt->dst);
  }

  enum fib6_walk_state {
  #ifdef CONFIG_IPV6_SUBTREES
  	FWS_S,
  #endif
  	FWS_L,
  	FWS_R,
  	FWS_C,
  	FWS_U
  };
  
  struct fib6_walker {

  	struct list_head lh;

  	struct fib6_node *root, *node;
  	struct rt6_info *leaf;

  	enum fib6_walk_state state;
  	bool prune;

  	unsigned int skip;
  	unsigned int count;

  	int (*func)(struct fib6_walker *);

  	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;

  	struct inet_peer_base	tb6_peers;

  	unsigned int		flags;
  #define RT6_TABLE_HAS_DFLT_ROUTER	BIT(0)

  };
  
  #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 flowi6 *, int);

  
  /*
   *	exported functions
   */

  struct fib6_table *fib6_get_table(struct net *net, u32 id);
  struct fib6_table *fib6_new_table(struct net *net, u32 id);
  struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
  				   int flags, pol_lookup_t lookup);

  struct fib6_node *fib6_lookup(struct fib6_node *root,
  			      const struct in6_addr *daddr,
  			      const struct in6_addr *saddr);

  struct fib6_node *fib6_locate(struct fib6_node *root,
  			      const struct in6_addr *daddr, int dst_len,
  			      const struct in6_addr *saddr, int src_len);

  void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),

  		    void *arg);

  int fib6_add(struct fib6_node *root, struct rt6_info *rt,
  	     struct nl_info *info, struct mx6_config *mxc);

  int fib6_del(struct rt6_info *rt, struct nl_info *info);

  void inet6_rt_notify(int event, struct rt6_info *rt, struct nl_info *info,
  		     unsigned int flags);

  void fib6_run_gc(unsigned long expires, struct net *net, bool force);

  void fib6_gc_cleanup(void);

  int fib6_init(void);

  int ipv6_route_open(struct inode *inode, struct file *file);

  #ifdef CONFIG_IPV6_MULTIPLE_TABLES

  int fib6_rules_init(void);
  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