Root/fs/ext4/xattr_trusted.c

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 "ext4_jbd2.h"
13#include "ext4.h"
14#include "xattr.h"
15
16static size_t
17ext4_xattr_trusted_list(struct inode *inode, char *list, size_t list_size,
18            const char *name, size_t name_len)
19{
20    const size_t prefix_len = XATTR_TRUSTED_PREFIX_LEN;
21    const size_t total_len = prefix_len + name_len + 1;
22
23    if (!capable(CAP_SYS_ADMIN))
24        return 0;
25
26    if (list && total_len <= list_size) {
27        memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
28        memcpy(list+prefix_len, name, name_len);
29        list[prefix_len + name_len] = '\0';
30    }
31    return total_len;
32}
33
34static int
35ext4_xattr_trusted_get(struct inode *inode, const char *name,
36               void *buffer, size_t size)
37{
38    if (strcmp(name, "") == 0)
39        return -EINVAL;
40    return ext4_xattr_get(inode, EXT4_XATTR_INDEX_TRUSTED, name,
41                  buffer, size);
42}
43
44static int
45ext4_xattr_trusted_set(struct inode *inode, const char *name,
46               const void *value, size_t size, int flags)
47{
48    if (strcmp(name, "") == 0)
49        return -EINVAL;
50    return ext4_xattr_set(inode, EXT4_XATTR_INDEX_TRUSTED, name,
51                  value, size, flags);
52}
53
54struct xattr_handler ext4_xattr_trusted_handler = {
55    .prefix = XATTR_TRUSTED_PREFIX,
56    .list = ext4_xattr_trusted_list,
57    .get = ext4_xattr_trusted_get,
58    .set = ext4_xattr_trusted_set,
59};
60

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