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/module.h>
9#include <linux/string.h>
10#include <linux/capability.h>
11#include <linux/fs.h>
12#include <linux/ext4_jbd2.h>
13#include <linux/ext4_fs.h>
14#include "xattr.h"
15
16#define XATTR_TRUSTED_PREFIX "trusted."
17
18static size_t
19ext4_xattr_trusted_list(struct inode *inode, char *list, size_t list_size,
20			const char *name, size_t name_len)
21{
22	const size_t prefix_len = sizeof(XATTR_TRUSTED_PREFIX)-1;
23	const size_t total_len = prefix_len + name_len + 1;
24
25	if (!capable(CAP_SYS_ADMIN))
26		return 0;
27
28	if (list && total_len <= list_size) {
29		memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
30		memcpy(list+prefix_len, name, name_len);
31		list[prefix_len + name_len] = '\0';
32	}
33	return total_len;
34}
35
36static int
37ext4_xattr_trusted_get(struct inode *inode, const char *name,
38		       void *buffer, size_t size)
39{
40	if (strcmp(name, "") == 0)
41		return -EINVAL;
42	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_TRUSTED, name,
43			      buffer, size);
44}
45
46static int
47ext4_xattr_trusted_set(struct inode *inode, const char *name,
48		       const void *value, size_t size, int flags)
49{
50	if (strcmp(name, "") == 0)
51		return -EINVAL;
52	return ext4_xattr_set(inode, EXT4_XATTR_INDEX_TRUSTED, name,
53			      value, size, flags);
54}
55
56struct xattr_handler ext4_xattr_trusted_handler = {
57	.prefix	= XATTR_TRUSTED_PREFIX,
58	.list	= ext4_xattr_trusted_list,
59	.get	= ext4_xattr_trusted_get,
60	.set	= ext4_xattr_trusted_set,
61};
62