path: root/fs/f2fs/xattr.c

// SPDX-License-Identifier: GPL-2.0
/*
 * fs/f2fs/xattr.c
 *
 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
 *             http://www.samsung.com/
 *
 * Portions of this code from linux/fs/ext2/xattr.c
 *
 * Copyright (C) 2001-2003 Andreas Gruenbacher <agruen@suse.de>
 *
 * Fix by Harrison Xing <harrison@mountainviewdata.com>.
 * Extended attributes for symlinks and special files added per
 *  suggestion of Luka Renko <luka.renko@hermes.si>.
 * xattr consolidation Copyright (c) 2004 James Morris <jmorris@redhat.com>,
 *  Red Hat Inc.
 */
#include <linux/rwsem.h>
#include <linux/f2fs_fs.h>
#include <linux/security.h>
#include <linux/posix_acl_xattr.h>
#include "f2fs.h"
#include "xattr.h"
#include "segment.h"

static struct kmem_cache *inline_xattr_slab;
static void *xattr_alloc(struct f2fs_sb_info *sbi, int size, bool *is_inline)
{
	if (likely(size == DEFAULT_XATTR_SLAB_SIZE)) {
		*is_inline = true;
		return f2fs_kmem_cache_alloc(inline_xattr_slab,
					GFP_F2FS_ZERO, false, sbi);
	}
	*is_inline = false;
	return f2fs_kzalloc(sbi, size, GFP_NOFS);
}

static void xattr_free(struct f2fs_sb_info *sbi, void *xattr_addr,
							bool is_inline)
{
	if (is_inline)
		kmem_cache_free(inline_xattr_slab, xattr_addr);
	else
		kfree(xattr_addr);
}

static int f2fs_xattr_generic_get(const struct xattr_handler *handler,
		struct dentry *unused, struct inode *inode,
		const char *name, void *buffer, size_t size)
{
	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);

	switch (handler->flags) {
	case F2FS_XATTR_INDEX_USER:
		if (!test_opt(sbi, XATTR_USER))
			return -EOPNOTSUPP;
		break;
	case F2FS_XATTR_INDEX_TRUSTED:
	case F2FS_XATTR_INDEX_SECURITY:
		break;
	default:
		return -EINVAL;
	}
	return f2fs_getxattr(inode, handler->flags, name,
			     buffer, size, NULL);
}

static int f2fs_xattr_generic_set(const struct xattr_handler *handler,
		struct mnt_idmap *idmap,
		struct dentry *unused, struct inode *inode,
		const char *name, const void *value,
		size_t size, int flags)
{
	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);

	switch (handler->flags) {
	case F2FS_XATTR_INDEX_USER:
		if (!test_opt(sbi, XATTR_USER))
			return -EOPNOTSUPP;
		break;
	case F2FS_XATTR_INDEX_TRUSTED:
	case F2FS_XATTR_INDEX_SECURITY:
		break;
	default:
		return -EINVAL;
	}
	return f2fs_setxattr(inode, handler->flags, name,
					value, size, NULL, flags);
}

static bool f2fs_xattr_user_list(struct dentry *dentry)
{
	struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);

	return test_opt(sbi, XATTR_USER);
}

static bool f2fs_xattr_trusted_list(struct dentry *dentry)
{
	return capable(CAP_SYS_ADMIN);
}

static int f2fs_xattr_advise_get(const struct xattr_handler *handler,
		struct dentry *unused, struct inode *inode,
		const char *name, void *buffer, size_t size)
{
	if (buffer)
		*((char *)buffer) = F2FS_I(inode)->i_advise;
	return sizeof(char);
}

static int f2fs_xattr_advise_set(const struct xattr_handler *handler,
		struct mnt_idmap *idmap,
		struct dentry *unused, struct inode *inode,
		const char *name, const void *value,
		size_t size, int flags)
{
	unsigned char old_advise = F2FS_I(inode)->i_advise;
	unsigned char new_advise;

	if (!inode_owner_or_capable(&nop_mnt_idmap, inode))
		return -EPERM;
	if (value == NULL)
		return -EINVAL;

	new_advise = *(char *)value;
	if (new_advise & ~FADVISE_MODIFIABLE_BITS)
		return -EINVAL;

	new_advise = new_advise & FADVISE_MODIFIABLE_BITS;
	new_advise |= old_advise & ~FADVISE_MODIFIABLE_BITS;

	F2FS_I(inode)->i_advise = new_advise;
	f2fs_mark_inode_dirty_sync(inode, true);
	return 0;
}

#ifdef CONFIG_F2FS_FS_SECURITY
static int f2fs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
		void *folio)
{
	const struct xattr *xattr;
	int err = 0;

	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
		err = f2fs_setxattr(inode, F2FS_XATTR_INDEX_SECURITY,
				xattr->name, xattr->value,
				xattr->value_len, folio, 0);
		if (err < 0)
			break;
	}
	return err;
}

int f2fs_init_security(struct inode *inode, struct inode *dir,
				const struct qstr *qstr, struct folio *ifolio)
{