xref: /openbmc/linux/fs/ext2/xattr_trusted.c (revision 384740dc)
1 /*
2  * linux/fs/ext2/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/ext2_fs.h>
13 #include "xattr.h"
14 
15 static size_t
16 ext2_xattr_trusted_list(struct inode *inode, char *list, size_t list_size,
17 			const char *name, size_t name_len)
18 {
19 	const int 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 
33 static int
34 ext2_xattr_trusted_get(struct inode *inode, const char *name,
35 		       void *buffer, size_t size)
36 {
37 	if (strcmp(name, "") == 0)
38 		return -EINVAL;
39 	return ext2_xattr_get(inode, EXT2_XATTR_INDEX_TRUSTED, name,
40 			      buffer, size);
41 }
42 
43 static int
44 ext2_xattr_trusted_set(struct inode *inode, const char *name,
45 		       const void *value, size_t size, int flags)
46 {
47 	if (strcmp(name, "") == 0)
48 		return -EINVAL;
49 	return ext2_xattr_set(inode, EXT2_XATTR_INDEX_TRUSTED, name,
50 			      value, size, flags);
51 }
52 
53 struct xattr_handler ext2_xattr_trusted_handler = {
54 	.prefix	= XATTR_TRUSTED_PREFIX,
55 	.list	= ext2_xattr_trusted_list,
56 	.get	= ext2_xattr_trusted_get,
57 	.set	= ext2_xattr_trusted_set,
58 };
59