kernel-ark/fs/ext3/xattr.h
Eric Paris 2a7dba391e fs/vfs/security: pass last path component to LSM on inode creation
SELinux would like to implement a new labeling behavior of newly created
inodes.  We currently label new inodes based on the parent and the creating
process.  This new behavior would also take into account the name of the
new object when deciding the new label.  This is not the (supposed) full path,
just the last component of the path.

This is very useful because creating /etc/shadow is different than creating
/etc/passwd but the kernel hooks are unable to differentiate these
operations.  We currently require that userspace realize it is doing some
difficult operation like that and than userspace jumps through SELinux hoops
to get things set up correctly.  This patch does not implement new
behavior, that is obviously contained in a seperate SELinux patch, but it
does pass the needed name down to the correct LSM hook.  If no such name
exists it is fine to pass NULL.

Signed-off-by: Eric Paris <eparis@redhat.com>
2011-02-01 11:12:29 -05:00

139 lines
3.9 KiB
C

/*
File: fs/ext3/xattr.h
On-disk format of extended attributes for the ext3 filesystem.
(C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
*/
#include <linux/xattr.h>
/* Magic value in attribute blocks */
#define EXT3_XATTR_MAGIC 0xEA020000
/* Maximum number of references to one attribute block */
#define EXT3_XATTR_REFCOUNT_MAX 1024
/* Name indexes */
#define EXT3_XATTR_INDEX_USER 1
#define EXT3_XATTR_INDEX_POSIX_ACL_ACCESS 2
#define EXT3_XATTR_INDEX_POSIX_ACL_DEFAULT 3
#define EXT3_XATTR_INDEX_TRUSTED 4
#define EXT3_XATTR_INDEX_LUSTRE 5
#define EXT3_XATTR_INDEX_SECURITY 6
struct ext3_xattr_header {
__le32 h_magic; /* magic number for identification */
__le32 h_refcount; /* reference count */
__le32 h_blocks; /* number of disk blocks used */
__le32 h_hash; /* hash value of all attributes */
__u32 h_reserved[4]; /* zero right now */
};
struct ext3_xattr_ibody_header {
__le32 h_magic; /* magic number for identification */
};
struct ext3_xattr_entry {
__u8 e_name_len; /* length of name */
__u8 e_name_index; /* attribute name index */
__le16 e_value_offs; /* offset in disk block of value */
__le32 e_value_block; /* disk block attribute is stored on (n/i) */
__le32 e_value_size; /* size of attribute value */
__le32 e_hash; /* hash value of name and value */
char e_name[0]; /* attribute name */
};
#define EXT3_XATTR_PAD_BITS 2
#define EXT3_XATTR_PAD (1<<EXT3_XATTR_PAD_BITS)
#define EXT3_XATTR_ROUND (EXT3_XATTR_PAD-1)
#define EXT3_XATTR_LEN(name_len) \
(((name_len) + EXT3_XATTR_ROUND + \
sizeof(struct ext3_xattr_entry)) & ~EXT3_XATTR_ROUND)
#define EXT3_XATTR_NEXT(entry) \
( (struct ext3_xattr_entry *)( \
(char *)(entry) + EXT3_XATTR_LEN((entry)->e_name_len)) )
#define EXT3_XATTR_SIZE(size) \
(((size) + EXT3_XATTR_ROUND) & ~EXT3_XATTR_ROUND)
# ifdef CONFIG_EXT3_FS_XATTR
extern const struct xattr_handler ext3_xattr_user_handler;
extern const struct xattr_handler ext3_xattr_trusted_handler;
extern const struct xattr_handler ext3_xattr_acl_access_handler;
extern const struct xattr_handler ext3_xattr_acl_default_handler;
extern const struct xattr_handler ext3_xattr_security_handler;
extern ssize_t ext3_listxattr(struct dentry *, char *, size_t);
extern int ext3_xattr_get(struct inode *, int, const char *, void *, size_t);
extern int ext3_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
extern int ext3_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
extern void ext3_xattr_delete_inode(handle_t *, struct inode *);
extern void ext3_xattr_put_super(struct super_block *);
extern int init_ext3_xattr(void);
extern void exit_ext3_xattr(void);
extern const struct xattr_handler *ext3_xattr_handlers[];
# else /* CONFIG_EXT3_FS_XATTR */
static inline int
ext3_xattr_get(struct inode *inode, int name_index, const char *name,
void *buffer, size_t size, int flags)
{
return -EOPNOTSUPP;
}
static inline int
ext3_xattr_set(struct inode *inode, int name_index, const char *name,
const void *value, size_t size, int flags)
{
return -EOPNOTSUPP;
}
static inline int
ext3_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index,
const char *name, const void *value, size_t size, int flags)
{
return -EOPNOTSUPP;
}
static inline void
ext3_xattr_delete_inode(handle_t *handle, struct inode *inode)
{
}
static inline void
ext3_xattr_put_super(struct super_block *sb)
{
}
static inline int
init_ext3_xattr(void)
{
return 0;
}
static inline void
exit_ext3_xattr(void)
{
}
#define ext3_xattr_handlers NULL
# endif /* CONFIG_EXT3_FS_XATTR */
#ifdef CONFIG_EXT3_FS_SECURITY
extern int ext3_init_security(handle_t *handle, struct inode *inode,
struct inode *dir, const struct qstr *qstr);
#else
static inline int ext3_init_security(handle_t *handle, struct inode *inode,
struct inode *dir, const struct qstr *qstr)
{
return 0;
}
#endif