/*
 *	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 <net/dst.h>
#include <net/flow.h>
#include <linux/rtnetlink.h>
#include <linux/spinlock.h>

struct rt6_info;

struct fib6_node
{
	struct fib6_node	*parent;
	struct fib6_node	*left;
	struct fib6_node	*right;

	struct fib6_node	*subtree;

	struct rt6_info		*leaf;

	__u16			fn_bit;		/* bit key */
	__u16			fn_flags;
	__u32			fn_sernum;
};


/*
 *	routing information
 *
 */

struct rt6key
{
	struct in6_addr	addr;
	int		plen;
};

struct fib6_table;

struct rt6_info
{
	union {
		struct dst_entry	dst;
		struct rt6_info		*next;
	} u;

	struct inet6_dev		*rt6i_idev;

#define rt6i_dev			u.dst.dev
#define rt6i_nexthop			u.dst.neighbour
#define rt6i_expires			u.dst.expires

	struct fib6_node		*rt6i_node;

	struct in6_addr			rt6i_gateway;
	
	u32				rt6i_flags;
	u32				rt6i_metric;
	atomic_t			rt6i_ref;
	struct fib6_table		*rt6i_table;

	struct rt6key			rt6i_dst;
	struct rt6key			rt6i_src;

	u8				rt6i_protocol;
};

struct fib6_walker_t
{
	struct fib6_walker_t *prev, *next;
	struct fib6_node *root, *node;
	struct rt6_info *leaf;
	unsigned char state;
	unsigned char prune;
	int (*func)(struct fib6_walker_t *);
	void *args;
};

extern struct fib6_walker_t fib6_walker_list;
extern rwlock_t fib6_walker_lock;

static inline void fib6_walker_link(struct fib6_walker_t *w)
{
	write_lock_bh(&fib6_walker_lock);
	w->next = fib6_walker_list.next;
	w->prev = &fib6_walker_list;
	w->next->prev = w;
	w->prev->next = w;
	write_unlock_bh(&fib6_walker_lock);
}

static inline void fib6_walker_unlink(struct fib6_walker_t *w)
{
	write_lock_bh(&fib6_walker_lock);
	w->next->prev = w->prev;
	w->prev->next = w->next;
	w->prev = w->next = w;
	write_unlock_bh(&fib6_walker_lock);
}

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)
 *
 */

#define RTPRI_FIREWALL	8		/* Firewall control information	*/
#define RTPRI_FLOW	16		/* Flow based forwarding rules	*/
#define RTPRI_KERN_CTL	32		/* Kernel control routes	*/

#define RTPRI_USER_MIN	256		/* Mimimum user priority	*/
#define RTPRI_USER_MAX	1024		/* Maximum user priority	*/

#define RTPRI_KERN_DFLT	4096		/* Kernel default routes	*/

#define	MAX_FLOW_BACKTRACE	32


typedef void			(*f_pnode)(struct fib6_node *fn, void *);

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

#define RT6_F_STRICT		1
#define RT6_F_HAS_SADDR		2

typedef struct rt6_info *(*pol_lookup_t)(struct fib6_table *,
					 struct flowi *, int);

/*
 *	exported functions
 */

extern struct fib6_table *	fib6_get_table(u32 id);
extern struct fib6_table *	fib6_new_table(u32 id);
extern struct dst_entry *	fib6_rule_lookup(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_tree(struct fib6_node *root,
						int (*func)(struct rt6_info *, void *arg),
						int prune, void *arg);

extern void			fib6_clean_all(int (*func)(struct rt6_info *, void *arg),
					       int prune, void *arg);

extern int			fib6_walk(struct fib6_walker_t *w);
extern int			fib6_walk_continue(struct fib6_walker_t *w);

extern int			fib6_add(struct fib6_node *root,
					 struct rt6_info *rt,
					 struct nlmsghdr *nlh,
					 void *rtattr,
					 struct netlink_skb_parms *req);

extern int			fib6_del(struct rt6_info *rt,
					 struct nlmsghdr *nlh,
					 void *rtattr,
					 struct netlink_skb_parms *req);

extern void			inet6_rt_notify(int event, struct rt6_info *rt,
						struct nlmsghdr *nlh,
						struct netlink_skb_parms *req);

extern void			fib6_run_gc(unsigned long dummy);

extern void			fib6_gc_cleanup(void);

extern void			fib6_init(void);

extern void			fib6_rules_init(void);
extern void			fib6_rules_cleanup(void);
extern int			fib6_rules_dump(struct sk_buff *,
						struct netlink_callback *);

#endif
#endif