/*
 *	Definitions for the generic connection tracking handling
 *
 *	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 _LINUX_GENERIC_CT_H
#define _LINUX_GENERIC_CT_H

#ifdef __KERNEL__
enum generic_ct_dir {
   GENERIC_CT_DIR_ORIGINAL = 0,
   GENERIC_CT_DIR_REPLY = 1,
   GENERIC_CT_DIR_MAX = 2
};

struct generic_ct;

struct generic_ct_ops {
   void (*destroy)(struct generic_ct *);

   /* set session id, NULL means: clear session id */
   void (*sessionid_set)(struct generic_ct *, enum generic_ct_dir,  void *);
   /* get session id, NULL means: no session id */
   void *(*sessionid_get)(struct generic_ct *, enum generic_ct_dir);
};

struct generic_ct {
   void                         *ct;
   struct generic_ct_ops *ops;
   /* */
   atomic_t                      use;
}; 

extern void generic_ct_init(void);

extern struct generic_ct *
generic_ct_create(void *ct, struct generic_ct_ops *ops, gfp_t gfp_mask);
extern void 
generic_ct_destroy(struct generic_ct *ct);


static inline void generic_ct_put(struct generic_ct *ct)
{
	if (ct && atomic_dec_and_test(&ct->use))
	   generic_ct_destroy(ct);
}

static inline struct generic_ct *generic_ct_get(struct generic_ct *ct)
{
	if (ct)
		atomic_inc(&ct->use);
    return ct;
}

/*
 * wrapper for ops
 */

static inline void generic_ct_sessionid_set(struct generic_ct *ct,
                                            enum generic_ct_dir dir,
											void *sessid)
{
   if (ct->ops && ct->ops->sessionid_set)
	  (*ct->ops->sessionid_set)(ct, dir, sessid);
}

static inline void *generic_ct_sessionid_get(struct generic_ct *ct,
                                             enum generic_ct_dir dir)
{
   if (ct->ops && ct->ops->sessionid_get)
	  return (*ct->ops->sessionid_get)(ct, dir);
   return 0;
}

#endif /* __KERNEL__ */
#endif /* _LINUX_GENERIC_CT_H */