/*

   * linux/fs/ext4/xattr_security.c

   * Handler for storing security labels as extended attributes.
   */
  
  #include <linux/module.h>
  #include <linux/string.h>
  #include <linux/fs.h>

  #include <linux/ext4_jbd2.h>

  #include <linux/ext4_fs.h>

  #include <linux/security.h>
  #include "xattr.h"
  
  static size_t

  ext4_xattr_security_list(struct inode *inode, char *list, size_t list_size,

  			 const char *name, size_t name_len)
  {
  	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 inode *inode, const char *name,

  		       void *buffer, size_t size)
  {
  	if (strcmp(name, "") == 0)
  		return -EINVAL;

  	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_SECURITY, name,

  			      buffer, size);
  }
  
  static int

  ext4_xattr_security_set(struct inode *inode, const char *name,

  		       const void *value, size_t size, int flags)
  {
  	if (strcmp(name, "") == 0)
  		return -EINVAL;

  	return ext4_xattr_set(inode, EXT4_XATTR_INDEX_SECURITY, name,

  			      value, size, flags);
  }
  
  int

  ext4_init_security(handle_t *handle, struct inode *inode, struct inode *dir)

  {
  	int err;
  	size_t len;
  	void *value;
  	char *name;
  
  	err = security_inode_init_security(inode, dir, &name, &value, &len);
  	if (err) {
  		if (err == -EOPNOTSUPP)
  			return 0;
  		return err;
  	}

  	err = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_SECURITY,

  				    name, value, len, 0);
  	kfree(name);
  	kfree(value);
  	return err;
  }

  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,

  };