/*

   * linux/fs/ext4/xattr_security.c

   * Handler for storing security labels as extended attributes.
   */

  #include <linux/string.h>
  #include <linux/fs.h>

  #include <linux/security.h>

  #include <linux/slab.h>

  #include "ext4_jbd2.h"
  #include "ext4.h"

  #include "xattr.h"
  
  static size_t

  ext4_xattr_security_list(struct dentry *dentry, char *list, size_t list_size,
  		const char *name, size_t name_len, int type)

  {
  	const size_t prefix_len = sizeof(XATTR_SECURITY_PREFIX)-1;
  	const size_t total_len = prefix_len + name_len + 1;
  
  
  	if (list && total_len <= list_size) {
  		memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
  		memcpy(list+prefix_len, name, name_len);
  		list[prefix_len + name_len] = '\0';
  	}
  	return total_len;
  }
  
  static int

  ext4_xattr_security_get(struct dentry *dentry, const char *name,
  		       void *buffer, size_t size, int type)

  {
  	if (strcmp(name, "") == 0)
  		return -EINVAL;

  	return ext4_xattr_get(dentry->d_inode, EXT4_XATTR_INDEX_SECURITY,
  			      name, buffer, size);

  }
  
  static int

  ext4_xattr_security_set(struct dentry *dentry, const char *name,
  		const void *value, size_t size, int flags, int type)

  {
  	if (strcmp(name, "") == 0)
  		return -EINVAL;

  	return ext4_xattr_set(dentry->d_inode, EXT4_XATTR_INDEX_SECURITY,
  			      name, value, size, flags);

  }

  static int
  ext4_initxattrs(struct inode *inode, const struct xattr *xattr_array,
  		void *fs_info)

  {

  	const struct xattr *xattr;
  	handle_t *handle = fs_info;
  	int err = 0;

  	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
  		err = ext4_xattr_set_handle(handle, inode,
  					    EXT4_XATTR_INDEX_SECURITY,
  					    xattr->name, xattr->value,
  					    xattr->value_len, 0);
  		if (err < 0)
  			break;

  	}

  	return err;
  }

  int
  ext4_init_security(handle_t *handle, struct inode *inode, struct inode *dir,
  		   const struct qstr *qstr)
  {
  	return security_inode_init_security(inode, dir, qstr,
  					    &ext4_initxattrs, handle);
  }

  const struct xattr_handler ext4_xattr_security_handler = {

  	.prefix	= XATTR_SECURITY_PREFIX,

  	.list	= ext4_xattr_security_list,
  	.get	= ext4_xattr_security_get,
  	.set	= ext4_xattr_security_set,

  };