include/linux/xattr.h

/*
  File: linux/xattr.h

  Extended attributes handling.

  Copyright (C) 2001 by Andreas Gruenbacher <a.gruenbacher@computer.org>
  Copyright (c) 2001-2002 Silicon Graphics, Inc.  All Rights Reserved.
  Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
*/
#ifndef _LINUX_XATTR_H
#define _LINUX_XATTR_H

#define XATTR_CREATE	0x1	/* set value, fail if attr already exists */
#define XATTR_REPLACE	0x2	/* set value, fail if attr does not exist */

/* Namespaces */
#define XATTR_OS2_PREFIX "os2."
#define XATTR_OS2_PREFIX_LEN (sizeof (XATTR_OS2_PREFIX) - 1)

#define XATTR_SECURITY_PREFIX	"security."
#define XATTR_SECURITY_PREFIX_LEN (sizeof (XATTR_SECURITY_PREFIX) - 1)

#define XATTR_SYSTEM_PREFIX "system."
#define XATTR_SYSTEM_PREFIX_LEN (sizeof (XATTR_SYSTEM_PREFIX) - 1)

#define XATTR_TRUSTED_PREFIX "trusted."
#define XATTR_TRUSTED_PREFIX_LEN (sizeof (XATTR_TRUSTED_PREFIX) - 1)

#define XATTR_USER_PREFIX "user."
#define XATTR_USER_PREFIX_LEN (sizeof (XATTR_USER_PREFIX) - 1)

/* Security namespace */
#define XATTR_EVM_SUFFIX "evm"
#define XATTR_NAME_EVM XATTR_SECURITY_PREFIX XATTR_EVM_SUFFIX

#define XATTR_SELINUX_SUFFIX "selinux"
#define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX

#define XATTR_SMACK_SUFFIX "SMACK64"
#define XATTR_SMACK_IPIN "SMACK64IPIN"
#define XATTR_SMACK_IPOUT "SMACK64IPOUT"
#define XATTR_SMACK_EXEC "SMACK64EXEC"
#define XATTR_SMACK_TRANSMUTE "SMACK64TRANSMUTE"
#define XATTR_SMACK_MMAP "SMACK64MMAP"
#define XATTR_NAME_SMACK XATTR_SECURITY_PREFIX XATTR_SMACK_SUFFIX
#define XATTR_NAME_SMACKIPIN	XATTR_SECURITY_PREFIX XATTR_SMACK_IPIN
#define XATTR_NAME_SMACKIPOUT	XATTR_SECURITY_PREFIX XATTR_SMACK_IPOUT
#define XATTR_NAME_SMACKEXEC	XATTR_SECURITY_PREFIX XATTR_SMACK_EXEC
#define XATTR_NAME_SMACKTRANSMUTE XATTR_SECURITY_PREFIX XATTR_SMACK_TRANSMUTE
#define XATTR_NAME_SMACKMMAP XATTR_SECURITY_PREFIX XATTR_SMACK_MMAP

#define XATTR_CAPS_SUFFIX "capability"
#define XATTR_NAME_CAPS XATTR_SECURITY_PREFIX XATTR_CAPS_SUFFIX

#define XATTR_POSIX_ACL_ACCESS  "posix_acl_access"
#define XATTR_NAME_POSIX_ACL_ACCESS XATTR_SYSTEM_PREFIX XATTR_POSIX_ACL_ACCESS
#define XATTR_POSIX_ACL_DEFAULT  "posix_acl_default"
#define XATTR_NAME_POSIX_ACL_DEFAULT XATTR_SYSTEM_PREFIX XATTR_POSIX_ACL_DEFAULT

#ifdef  __KERNEL__

#include <linux/slab.h>
#include <linux/types.h>
#include <linux/spinlock.h>

struct inode;
struct dentry;

struct xattr_handler {
	const char *prefix;
	int flags;	/* fs private flags passed back to the handlers */
	size_t (*list)(struct dentry *dentry, char *list, size_t list_size,
		       const char *name, size_t name_len, int handler_flags);
	int (*get)(struct dentry *dentry, const char *name, void *buffer,
		   size_t size, int handler_flags);
	int (*set)(struct dentry *dentry, const char *name, const void *buffer,
		   size_t size, int flags, int handler_flags);
};

struct xattr {
	char *name;
	void *value;
	size_t value_len;
};

ssize_t xattr_getsecurity(struct inode *, const char *, void *, size_t);
ssize_t vfs_getxattr(struct dentry *, const char *, void *, size_t);
ssize_t vfs_listxattr(struct dentry *d, char *list, size_t size);
int __vfs_setxattr_noperm(struct dentry *, const char *, const void *, size_t, int);
int vfs_setxattr(struct dentry *, const char *, const void *, size_t, int);
int vfs_removexattr(struct dentry *, const char *);

ssize_t generic_getxattr(struct dentry *dentry, const char *name, void *buffer, size_t size);
ssize_t generic_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size);
int generic_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags);
int generic_removexattr(struct dentry *dentry, const char *name);
ssize_t vfs_getxattr_alloc(struct dentry *dentry, const char *name,
			   char **xattr_value, size_t size, gfp_t flags);
int vfs_xattr_cmp(struct dentry *dentry, const char *xattr_name,
		  const char *value, size_t size, gfp_t flags);

struct simple_xattrs {
	struct list_head head;
	spinlock_t lock;
};

struct simple_xattr {
	struct list_head list;
	char *name;
	size_t size;
	char value[0];
};

/*
 * initialize the simple_xattrs structure
 */
static inline void simple_xattrs_init(struct simple_xattrs *xattrs)
{
	INIT_LIST_HEAD(&xattrs->head);
	spin_lock_init(&xattrs->lock);
}

/*
 * free all the xattrs
 */
static inline void simple_xattrs_free(struct simple_xattrs *xattrs)
{
	struct simple_xattr *xattr, *node;

	list_for_each_entry_safe(xattr, node, &xattrs->head, list) {
		kfree(xattr->name);
		kfree(xattr);
	}
}

struct simple_xattr *simple_xattr_alloc(const void *value, size_t size);
int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
		     void *buffer, size_t size);
int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
		     const void *value, size_t size, int flags);
int simple_xattr_remove(struct simple_xattrs *xattrs, const char *name);
ssize_t simple_xattr_list(struct simple_xattrs *xattrs, char *buffer,
			  size_t size);
void simple_xattr_list_add(struct simple_xattrs *xattrs,
			   struct simple_xattr *new_xattr);

#endif  /*  __KERNEL__  */

#endif	/* _LINUX_XATTR_H */