[deliverable/linux.git] / include / linux / projid.h

#ifndef _LINUX_PROJID_H
#define _LINUX_PROJID_H

/*
 * A set of types for the internal kernel types representing project ids.
 *
 * The types defined in this header allow distinguishing which project ids in
 * the kernel are values used by userspace and which project id values are
 * the internal kernel values.  With the addition of user namespaces the values
 * can be different.  Using the type system makes it possible for the compiler
 * to detect when we overlook these differences.
 *
 */
#include <linux/types.h>

struct user_namespace;
extern struct user_namespace init_user_ns;

typedef __kernel_uid32_t projid_t;

typedef struct {
	projid_t val;
} kprojid_t;

static inline projid_t __kprojid_val(kprojid_t projid)
{
	return projid.val;
}

#define KPROJIDT_INIT(value) (kprojid_t){ value }

#define INVALID_PROJID KPROJIDT_INIT(-1)
#define OVERFLOW_PROJID 65534

static inline bool projid_eq(kprojid_t left, kprojid_t right)
{
	return __kprojid_val(left) == __kprojid_val(right);
}

static inline bool projid_lt(kprojid_t left, kprojid_t right)
{
	return __kprojid_val(left) < __kprojid_val(right);
}

static inline bool projid_valid(kprojid_t projid)
{
	return !projid_eq(projid, INVALID_PROJID);
}

#ifdef CONFIG_USER_NS

extern kprojid_t make_kprojid(struct user_namespace *from, projid_t projid);

extern projid_t from_kprojid(struct user_namespace *to, kprojid_t projid);
extern projid_t from_kprojid_munged(struct user_namespace *to, kprojid_t projid);

static inline bool kprojid_has_mapping(struct user_namespace *ns, kprojid_t projid)
{
	return from_kprojid(ns, projid) != (projid_t)-1;
}

#else

static inline kprojid_t make_kprojid(struct user_namespace *from, projid_t projid)
{
	return KPROJIDT_INIT(projid);
}

static inline projid_t from_kprojid(struct user_namespace *to, kprojid_t kprojid)
{
	return __kprojid_val(kprojid);
}

static inline projid_t from_kprojid_munged(struct user_namespace *to, kprojid_t kprojid)
{
	projid_t projid = from_kprojid(to, kprojid);
	if (projid == (projid_t)-1)
		projid = OVERFLOW_PROJID;
	return projid;
}

static inline bool kprojid_has_mapping(struct user_namespace *ns, kprojid_t projid)
{
	return true;
}

#endif /* CONFIG_USER_NS */

#endif /* _LINUX_PROJID_H */
Commit	Line	Data
	1	#ifndef _LINUX_PROJID_H
	2	#define _LINUX_PROJID_H
	3
	4	/*
	5	* A set of types for the internal kernel types representing project ids.
	6	*
	7	* The types defined in this header allow distinguishing which project ids in
	8	* the kernel are values used by userspace and which project id values are
	9	* the internal kernel values. With the addition of user namespaces the values
	10	* can be different. Using the type system makes it possible for the compiler
	11	* to detect when we overlook these differences.
	12	*
	13	*/
	14	#include <linux/types.h>
	15
	16	struct user_namespace;
	17	extern struct user_namespace init_user_ns;
	18
	19	typedef __kernel_uid32_t projid_t;
	20
	21	typedef struct {
	22	projid_t val;
	23	} kprojid_t;
	24
	25	static inline projid_t __kprojid_val(kprojid_t projid)
	26	{
	27	return projid.val;
	28	}
	29
	30	#define KPROJIDT_INIT(value) (kprojid_t){ value }
	31
	32	#define INVALID_PROJID KPROJIDT_INIT(-1)
	33	#define OVERFLOW_PROJID 65534
	34
	35	static inline bool projid_eq(kprojid_t left, kprojid_t right)
	36	{
	37	return __kprojid_val(left) == __kprojid_val(right);
	38	}
	39
	40	static inline bool projid_lt(kprojid_t left, kprojid_t right)
	41	{
	42	return __kprojid_val(left) < __kprojid_val(right);
	43	}
	44
	45	static inline bool projid_valid(kprojid_t projid)
	46	{
	47	return !projid_eq(projid, INVALID_PROJID);
	48	}
	49
	50	#ifdef CONFIG_USER_NS
	51
	52	extern kprojid_t make_kprojid(struct user_namespace *from, projid_t projid);
	53
	54	extern projid_t from_kprojid(struct user_namespace *to, kprojid_t projid);
	55	extern projid_t from_kprojid_munged(struct user_namespace *to, kprojid_t projid);
	56
	57	static inline bool kprojid_has_mapping(struct user_namespace *ns, kprojid_t projid)
	58	{
	59	return from_kprojid(ns, projid) != (projid_t)-1;
	60	}
	61
	62	#else
	63
	64	static inline kprojid_t make_kprojid(struct user_namespace *from, projid_t projid)
	65	{
	66	return KPROJIDT_INIT(projid);
	67	}
	68
	69	static inline projid_t from_kprojid(struct user_namespace *to, kprojid_t kprojid)
	70	{
	71	return __kprojid_val(kprojid);
	72	}
	73
	74	static inline projid_t from_kprojid_munged(struct user_namespace *to, kprojid_t kprojid)
	75	{
	76	projid_t projid = from_kprojid(to, kprojid);
	77	if (projid == (projid_t)-1)
	78	projid = OVERFLOW_PROJID;
	79	return projid;
	80	}
	81
	82	static inline bool kprojid_has_mapping(struct user_namespace *ns, kprojid_t projid)
	83	{
	84	return true;
	85	}
	86
	87	#endif /* CONFIG_USER_NS */
	88
	89	#endif /* _LINUX_PROJID_H */