[linux-2.6-block.git] / include / linux / capability.h

/*
 * This is <linux/capability.h>
 *
 * Andrew G. Morgan <morgan@kernel.org>
 * Alexander Kjeldaas <astor@guardian.no>
 * with help from Aleph1, Roland Buresund and Andrew Main.
 *
 * See here for the libcap library ("POSIX draft" compliance):
 *
 * ftp://www.kernel.org/pub/linux/libs/security/linux-privs/kernel-2.6/
 */
#ifndef _LINUX_CAPABILITY_H
#define _LINUX_CAPABILITY_H

#include <uapi/linux/capability.h>


#define _KERNEL_CAPABILITY_VERSION _LINUX_CAPABILITY_VERSION_3
#define _KERNEL_CAPABILITY_U32S    _LINUX_CAPABILITY_U32S_3

extern int file_caps_enabled;

typedef struct kernel_cap_struct {
	__u32 cap[_KERNEL_CAPABILITY_U32S];
} kernel_cap_t;

/* exact same as vfs_cap_data but in cpu endian and always filled completely */
struct cpu_vfs_cap_data {
	__u32 magic_etc;
	kernel_cap_t permitted;
	kernel_cap_t inheritable;
};

#define _USER_CAP_HEADER_SIZE  (sizeof(struct __user_cap_header_struct))
#define _KERNEL_CAP_T_SIZE     (sizeof(kernel_cap_t))


struct inode;
struct dentry;
struct user_namespace;

struct user_namespace *current_user_ns(void);

extern const kernel_cap_t __cap_empty_set;
extern const kernel_cap_t __cap_init_eff_set;

/*
 * Internal kernel functions only
 */

#define CAP_FOR_EACH_U32(__capi)  \
	for (__capi = 0; __capi < _KERNEL_CAPABILITY_U32S; ++__capi)

/*
 * CAP_FS_MASK and CAP_NFSD_MASKS:
 *
 * The fs mask is all the privileges that fsuid==0 historically meant.
 * At one time in the past, that included CAP_MKNOD and CAP_LINUX_IMMUTABLE.
 *
 * It has never meant setting security.* and trusted.* xattrs.
 *
 * We could also define fsmask as follows:
 *   1. CAP_FS_MASK is the privilege to bypass all fs-related DAC permissions
 *   2. The security.* and trusted.* xattrs are fs-related MAC permissions
 */

# define CAP_FS_MASK_B0     (CAP_TO_MASK(CAP_CHOWN)		\
			    | CAP_TO_MASK(CAP_MKNOD)		\
			    | CAP_TO_MASK(CAP_DAC_OVERRIDE)	\
			    | CAP_TO_MASK(CAP_DAC_READ_SEARCH)	\
			    | CAP_TO_MASK(CAP_FOWNER)		\
			    | CAP_TO_MASK(CAP_FSETID))

# define CAP_FS_MASK_B1     (CAP_TO_MASK(CAP_MAC_OVERRIDE))

#if _KERNEL_CAPABILITY_U32S != 2
# error Fix up hand-coded capability macro initializers
#else /* HAND-CODED capability initializers */

# define CAP_EMPTY_SET    ((kernel_cap_t){{ 0, 0 }})
# define CAP_FULL_SET     ((kernel_cap_t){{ ~0, ~0 }})
# define CAP_FS_SET       ((kernel_cap_t){{ CAP_FS_MASK_B0 \
				    | CAP_TO_MASK(CAP_LINUX_IMMUTABLE), \
				    CAP_FS_MASK_B1 } })
# define CAP_NFSD_SET     ((kernel_cap_t){{ CAP_FS_MASK_B0 \
				    | CAP_TO_MASK(CAP_SYS_RESOURCE), \
				    CAP_FS_MASK_B1 } })

#endif /* _KERNEL_CAPABILITY_U32S != 2 */

# define cap_clear(c)         do { (c) = __cap_empty_set; } while (0)

#define cap_raise(c, flag)  ((c).cap[CAP_TO_INDEX(flag)] |= CAP_TO_MASK(flag))
#define cap_lower(c, flag)  ((c).cap[CAP_TO_INDEX(flag)] &= ~CAP_TO_MASK(flag))
#define cap_raised(c, flag) ((c).cap[CAP_TO_INDEX(flag)] & CAP_TO_MASK(flag))

#define CAP_BOP_ALL(c, a, b, OP)                                    \
do {                                                                \
	unsigned __capi;                                            \
	CAP_FOR_EACH_U32(__capi) {                                  \
		c.cap[__capi] = a.cap[__capi] OP b.cap[__capi];     \
	}                                                           \
} while (0)

#define CAP_UOP_ALL(c, a, OP)                                       \
do {                                                                \
	unsigned __capi;                                            \
	CAP_FOR_EACH_U32(__capi) {                                  \
		c.cap[__capi] = OP a.cap[__capi];                   \
	}                                                           \
} while (0)

static inline kernel_cap_t cap_combine(const kernel_cap_t a,
				       const kernel_cap_t b)
{
	kernel_cap_t dest;
	CAP_BOP_ALL(dest, a, b, |);
	return dest;
}

static inline kernel_cap_t cap_intersect(const kernel_cap_t a,
					 const kernel_cap_t b)
{
	kernel_cap_t dest;
	CAP_BOP_ALL(dest, a, b, &);
	return dest;
}

static inline kernel_cap_t cap_drop(const kernel_cap_t a,
				    const kernel_cap_t drop)
{
	kernel_cap_t dest;
	CAP_BOP_ALL(dest, a, drop, &~);
	return dest;
}

static inline kernel_cap_t cap_invert(const kernel_cap_t c)
{
	kernel_cap_t dest;
	CAP_UOP_ALL(dest, c, ~);
	return dest;
}

static inline int cap_isclear(const kernel_cap_t a)
{
	unsigned __capi;
	CAP_FOR_EACH_U32(__capi) {
		if (a.cap[__capi] != 0)
			return 0;
	}
	return 1;
}

/*
 * Check if "a" is a subset of "set".
 * return 1 if ALL of the capabilities in "a" are also in "set"
 *	cap_issubset(0101, 1111) will return 1
 * return 0 if ANY of the capabilities in "a" are not in "set"
 *	cap_issubset(1111, 0101) will return 0
 */
static inline int cap_issubset(const kernel_cap_t a, const kernel_cap_t set)
{
	kernel_cap_t dest;
	dest = cap_drop(a, set);
	return cap_isclear(dest);
}

/* Used to decide between falling back on the old suser() or fsuser(). */

static inline int cap_is_fs_cap(int cap)
{
	const kernel_cap_t __cap_fs_set = CAP_FS_SET;
	return !!(CAP_TO_MASK(cap) & __cap_fs_set.cap[CAP_TO_INDEX(cap)]);
}

static inline kernel_cap_t cap_drop_fs_set(const kernel_cap_t a)
{
	const kernel_cap_t __cap_fs_set = CAP_FS_SET;
	return cap_drop(a, __cap_fs_set);
}

static inline kernel_cap_t cap_raise_fs_set(const kernel_cap_t a,
					    const kernel_cap_t permitted)
{
	const kernel_cap_t __cap_fs_set = CAP_FS_SET;
	return cap_combine(a,
			   cap_intersect(permitted, __cap_fs_set));
}

static inline kernel_cap_t cap_drop_nfsd_set(const kernel_cap_t a)
{
	const kernel_cap_t __cap_fs_set = CAP_NFSD_SET;
	return cap_drop(a, __cap_fs_set);
}

static inline kernel_cap_t cap_raise_nfsd_set(const kernel_cap_t a,
					      const kernel_cap_t permitted)
{
	const kernel_cap_t __cap_nfsd_set = CAP_NFSD_SET;
	return cap_combine(a,
			   cap_intersect(permitted, __cap_nfsd_set));
}

extern bool has_capability(struct task_struct *t, int cap);
extern bool has_ns_capability(struct task_struct *t,
			      struct user_namespace *ns, int cap);
extern bool has_capability_noaudit(struct task_struct *t, int cap);
extern bool has_ns_capability_noaudit(struct task_struct *t,
				      struct user_namespace *ns, int cap);
extern bool capable(int cap);
extern bool ns_capable(struct user_namespace *ns, int cap);
extern bool nsown_capable(int cap);
extern bool inode_capable(const struct inode *inode, int cap);

/* audit system wants to get cap info from files as well */
extern int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps);

#endif /* !_LINUX_CAPABILITY_H */
Commit	Line	Data
	1	/*
	2	* This is <linux/capability.h>
	3	*
	4	* Andrew G. Morgan <morgan@kernel.org>
	5	* Alexander Kjeldaas <astor@guardian.no>
	6	* with help from Aleph1, Roland Buresund and Andrew Main.
	7	*
	8	* See here for the libcap library ("POSIX draft" compliance):
	9	*
	10	* ftp://www.kernel.org/pub/linux/libs/security/linux-privs/kernel-2.6/
	11	*/
	12	#ifndef _LINUX_CAPABILITY_H
	13	#define _LINUX_CAPABILITY_H
	14
	15	#include <uapi/linux/capability.h>
	16
	17
	18	#define _KERNEL_CAPABILITY_VERSION _LINUX_CAPABILITY_VERSION_3
	19	#define _KERNEL_CAPABILITY_U32S _LINUX_CAPABILITY_U32S_3
	20
	21	extern int file_caps_enabled;
	22
	23	typedef struct kernel_cap_struct {
	24	__u32 cap[_KERNEL_CAPABILITY_U32S];
	25	} kernel_cap_t;
	26
	27	/* exact same as vfs_cap_data but in cpu endian and always filled completely */
	28	struct cpu_vfs_cap_data {
	29	__u32 magic_etc;
	30	kernel_cap_t permitted;
	31	kernel_cap_t inheritable;
	32	};
	33
	34	#define _USER_CAP_HEADER_SIZE (sizeof(struct __user_cap_header_struct))
	35	#define _KERNEL_CAP_T_SIZE (sizeof(kernel_cap_t))
	36
	37
	38	struct inode;
	39	struct dentry;
	40	struct user_namespace;
	41
	42	struct user_namespace *current_user_ns(void);
	43
	44	extern const kernel_cap_t __cap_empty_set;
	45	extern const kernel_cap_t __cap_init_eff_set;
	46
	47	/*
	48	* Internal kernel functions only
	49	*/
	50
	51	#define CAP_FOR_EACH_U32(__capi) \
	52	for (__capi = 0; __capi < _KERNEL_CAPABILITY_U32S; ++__capi)
	53
	54	/*
	55	* CAP_FS_MASK and CAP_NFSD_MASKS:
	56	*
	57	* The fs mask is all the privileges that fsuid==0 historically meant.
	58	* At one time in the past, that included CAP_MKNOD and CAP_LINUX_IMMUTABLE.
	59	*
	60	* It has never meant setting security.* and trusted.* xattrs.
	61	*
	62	* We could also define fsmask as follows:
	63	* 1. CAP_FS_MASK is the privilege to bypass all fs-related DAC permissions
	64	* 2. The security.* and trusted.* xattrs are fs-related MAC permissions
	65	*/
	66
	67	# define CAP_FS_MASK_B0 (CAP_TO_MASK(CAP_CHOWN) \
	68	\| CAP_TO_MASK(CAP_MKNOD) \
	69	\| CAP_TO_MASK(CAP_DAC_OVERRIDE) \
	70	\| CAP_TO_MASK(CAP_DAC_READ_SEARCH) \
	71	\| CAP_TO_MASK(CAP_FOWNER) \
	72	\| CAP_TO_MASK(CAP_FSETID))
	73
	74	# define CAP_FS_MASK_B1 (CAP_TO_MASK(CAP_MAC_OVERRIDE))
	75
	76	#if _KERNEL_CAPABILITY_U32S != 2
	77	# error Fix up hand-coded capability macro initializers
	78	#else /* HAND-CODED capability initializers */
	79
	80	# define CAP_EMPTY_SET ((kernel_cap_t){{ 0, 0 }})
	81	# define CAP_FULL_SET ((kernel_cap_t){{ ~0, ~0 }})
	82	# define CAP_FS_SET ((kernel_cap_t){{ CAP_FS_MASK_B0 \
	83	\| CAP_TO_MASK(CAP_LINUX_IMMUTABLE), \
	84	CAP_FS_MASK_B1 } })
	85	# define CAP_NFSD_SET ((kernel_cap_t){{ CAP_FS_MASK_B0 \
	86	\| CAP_TO_MASK(CAP_SYS_RESOURCE), \
	87	CAP_FS_MASK_B1 } })
	88
	89	#endif /* _KERNEL_CAPABILITY_U32S != 2 */
	90
	91	# define cap_clear(c) do { (c) = __cap_empty_set; } while (0)
	92
	93	#define cap_raise(c, flag) ((c).cap[CAP_TO_INDEX(flag)] \|= CAP_TO_MASK(flag))
	94	#define cap_lower(c, flag) ((c).cap[CAP_TO_INDEX(flag)] &= ~CAP_TO_MASK(flag))
	95	#define cap_raised(c, flag) ((c).cap[CAP_TO_INDEX(flag)] & CAP_TO_MASK(flag))
	96
	97	#define CAP_BOP_ALL(c, a, b, OP) \
	98	do { \
	99	unsigned __capi; \
	100	CAP_FOR_EACH_U32(__capi) { \
	101	c.cap[__capi] = a.cap[__capi] OP b.cap[__capi]; \
	102	} \
	103	} while (0)
	104
	105	#define CAP_UOP_ALL(c, a, OP) \
	106	do { \
	107	unsigned __capi; \
	108	CAP_FOR_EACH_U32(__capi) { \
	109	c.cap[__capi] = OP a.cap[__capi]; \
	110	} \
	111	} while (0)
	112
	113	static inline kernel_cap_t cap_combine(const kernel_cap_t a,
	114	const kernel_cap_t b)
	115	{
	116	kernel_cap_t dest;
	117	CAP_BOP_ALL(dest, a, b, \|);
	118	return dest;
	119	}
	120
	121	static inline kernel_cap_t cap_intersect(const kernel_cap_t a,
	122	const kernel_cap_t b)
	123	{
	124	kernel_cap_t dest;
	125	CAP_BOP_ALL(dest, a, b, &);
	126	return dest;
	127	}
	128
	129	static inline kernel_cap_t cap_drop(const kernel_cap_t a,
	130	const kernel_cap_t drop)
	131	{
	132	kernel_cap_t dest;
	133	CAP_BOP_ALL(dest, a, drop, &~);
	134	return dest;
	135	}
	136
	137	static inline kernel_cap_t cap_invert(const kernel_cap_t c)
	138	{
	139	kernel_cap_t dest;
	140	CAP_UOP_ALL(dest, c, ~);
	141	return dest;
	142	}
	143
	144	static inline int cap_isclear(const kernel_cap_t a)
	145	{
	146	unsigned __capi;
	147	CAP_FOR_EACH_U32(__capi) {
	148	if (a.cap[__capi] != 0)
	149	return 0;
	150	}
	151	return 1;
	152	}
	153
	154	/*
	155	* Check if "a" is a subset of "set".
	156	* return 1 if ALL of the capabilities in "a" are also in "set"
	157	* cap_issubset(0101, 1111) will return 1
	158	* return 0 if ANY of the capabilities in "a" are not in "set"
	159	* cap_issubset(1111, 0101) will return 0
	160	*/
	161	static inline int cap_issubset(const kernel_cap_t a, const kernel_cap_t set)
	162	{
	163	kernel_cap_t dest;
	164	dest = cap_drop(a, set);
	165	return cap_isclear(dest);
	166	}
	167
	168	/* Used to decide between falling back on the old suser() or fsuser(). */
	169
	170	static inline int cap_is_fs_cap(int cap)
	171	{
	172	const kernel_cap_t __cap_fs_set = CAP_FS_SET;
	173	return !!(CAP_TO_MASK(cap) & __cap_fs_set.cap[CAP_TO_INDEX(cap)]);
	174	}
	175
	176	static inline kernel_cap_t cap_drop_fs_set(const kernel_cap_t a)
	177	{
	178	const kernel_cap_t __cap_fs_set = CAP_FS_SET;
	179	return cap_drop(a, __cap_fs_set);
	180	}
	181
	182	static inline kernel_cap_t cap_raise_fs_set(const kernel_cap_t a,
	183	const kernel_cap_t permitted)
	184	{
	185	const kernel_cap_t __cap_fs_set = CAP_FS_SET;
	186	return cap_combine(a,
	187	cap_intersect(permitted, __cap_fs_set));
	188	}
	189
	190	static inline kernel_cap_t cap_drop_nfsd_set(const kernel_cap_t a)
	191	{
	192	const kernel_cap_t __cap_fs_set = CAP_NFSD_SET;
	193	return cap_drop(a, __cap_fs_set);
	194	}
	195
	196	static inline kernel_cap_t cap_raise_nfsd_set(const kernel_cap_t a,
	197	const kernel_cap_t permitted)
	198	{
	199	const kernel_cap_t __cap_nfsd_set = CAP_NFSD_SET;
	200	return cap_combine(a,
	201	cap_intersect(permitted, __cap_nfsd_set));
	202	}
	203
	204	extern bool has_capability(struct task_struct *t, int cap);
	205	extern bool has_ns_capability(struct task_struct *t,
	206	struct user_namespace *ns, int cap);
	207	extern bool has_capability_noaudit(struct task_struct *t, int cap);
	208	extern bool has_ns_capability_noaudit(struct task_struct *t,
	209	struct user_namespace *ns, int cap);
	210	extern bool capable(int cap);
	211	extern bool ns_capable(struct user_namespace *ns, int cap);
	212	extern bool nsown_capable(int cap);
	213	extern bool inode_capable(const struct inode *inode, int cap);
	214
	215	/* audit system wants to get cap info from files as well */
	216	extern int get_vfs_caps_from_disk(const struct dentry dentry, struct cpu_vfs_cap_data cpu_caps);
	217
	218	#endif /* !_LINUX_CAPABILITY_H */