1/*
2 * linux/fs/ext4/xattr_trusted.c
3 * Handler for trusted extended attributes.
4 *
5 * Copyright (C) 2003 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
6 */
7
8#include <linux/string.h>
9#include <linux/capability.h>
10#include <linux/fs.h>
11#include "ext4_jbd2.h"
12#include "ext4.h"
13#include "xattr.h"
14
15static size_t
16ext4_xattr_trusted_list(struct dentry *dentry, char *list, size_t list_size,
17		const char *name, size_t name_len, int type)
18{
19	const size_t prefix_len = XATTR_TRUSTED_PREFIX_LEN;
20	const size_t total_len = prefix_len + name_len + 1;
21
22	if (!capable(CAP_SYS_ADMIN))
23		return 0;
24
25	if (list && total_len <= list_size) {
26		memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
27		memcpy(list+prefix_len, name, name_len);
28		list[prefix_len + name_len] = '\0';
29	}
30	return total_len;
31}
32
33static int
34ext4_xattr_trusted_get(struct dentry *dentry, const char *name, void *buffer,
35		size_t size, int type)
36{
37	if (strcmp(name, "") == 0)
38		return -EINVAL;
39	return ext4_xattr_get(d_inode(dentry), EXT4_XATTR_INDEX_TRUSTED,
40			      name, buffer, size);
41}
42
43static int
44ext4_xattr_trusted_set(struct dentry *dentry, const char *name,
45		const void *value, size_t size, int flags, int type)
46{
47	if (strcmp(name, "") == 0)
48		return -EINVAL;
49	return ext4_xattr_set(d_inode(dentry), EXT4_XATTR_INDEX_TRUSTED,
50			      name, value, size, flags);
51}
52
53const struct xattr_handler ext4_xattr_trusted_handler = {
54	.prefix	= XATTR_TRUSTED_PREFIX,
55	.list	= ext4_xattr_trusted_list,
56	.get	= ext4_xattr_trusted_get,
57	.set	= ext4_xattr_trusted_set,
58};
59