// SPDX-License-Identifier: GPL-2.0

  #include "reiserfs.h"

  #include <linux/errno.h>
  #include <linux/fs.h>
  #include <linux/pagemap.h>
  #include <linux/xattr.h>

  #include <linux/slab.h>

  #include "xattr.h"

  #include <linux/security.h>

  #include <linux/uaccess.h>

  static int

  security_get(const struct xattr_handler *handler, struct dentry *unused,
  	     struct inode *inode, const char *name, void *buffer, size_t size)

  {

  	if (IS_PRIVATE(inode))

  		return -EPERM;

  	return reiserfs_xattr_get(inode, xattr_full_name(handler, name),

  				  buffer, size);

  }
  
  static int

  security_set(const struct xattr_handler *handler, struct dentry *unused,
  	     struct inode *inode, const char *name, const void *buffer,
  	     size_t size, int flags)

  {

  	if (IS_PRIVATE(inode))

  		return -EPERM;

  	return reiserfs_xattr_set(inode,

  				  xattr_full_name(handler, name),
  				  buffer, size, flags);

  }

  static bool security_list(struct dentry *dentry)

  {

  	return !IS_PRIVATE(d_inode(dentry));

  }

  /* Initializes the security context for a new inode and returns the number
   * of blocks needed for the transaction. If successful, reiserfs_security
   * must be released using reiserfs_security_free when the caller is done. */
  int reiserfs_security_init(struct inode *dir, struct inode *inode,

  			   const struct qstr *qstr,

  			   struct reiserfs_security_handle *sec)
  {
  	int blocks = 0;

  	int error;
  
  	sec->name = NULL;
  
  	/* Don't add selinux attributes on xattrs - they'll never get used */
  	if (IS_PRIVATE(dir))
  		return 0;

  	error = security_old_inode_init_security(inode, dir, qstr, &sec->name,
  						 &sec->value, &sec->length);

  	if (error) {
  		if (error == -EOPNOTSUPP)
  			error = 0;
  
  		sec->name = NULL;
  		sec->value = NULL;
  		sec->length = 0;
  		return error;
  	}

  	if (sec->length && reiserfs_xattrs_initialized(inode->i_sb)) {

  		blocks = reiserfs_xattr_jcreate_nblocks(inode) +
  			 reiserfs_xattr_nblocks(inode, sec->length);
  		/* We don't want to count the directories twice if we have
  		 * a default ACL. */
  		REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
  	}
  	return blocks;
  }
  
  int reiserfs_security_write(struct reiserfs_transaction_handle *th,
  			    struct inode *inode,
  			    struct reiserfs_security_handle *sec)
  {
  	int error;
  	if (strlen(sec->name) < sizeof(XATTR_SECURITY_PREFIX))
  		return -EINVAL;
  
  	error = reiserfs_xattr_set_handle(th, inode, sec->name, sec->value,
  					  sec->length, XATTR_CREATE);
  	if (error == -ENODATA || error == -EOPNOTSUPP)
  		error = 0;
  
  	return error;
  }
  
  void reiserfs_security_free(struct reiserfs_security_handle *sec)
  {
  	kfree(sec->name);
  	kfree(sec->value);
  	sec->name = NULL;
  	sec->value = NULL;
  }

  const struct xattr_handler reiserfs_xattr_security_handler = {

  	.prefix = XATTR_SECURITY_PREFIX,
  	.get = security_get,
  	.set = security_set,

  	.list = security_list,
  };