xref: /openbmc/linux/fs/ext2/xattr_trusted.c (revision 643d1f7f)
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 #define XATTR_TRUSTED_PREFIX "trusted."
16 
17 static size_t
18 ext2_xattr_trusted_list(struct inode *inode, char *list, size_t list_size,
19 			const char *name, size_t name_len)
20 {
21 	const int prefix_len = sizeof(XATTR_TRUSTED_PREFIX)-1;
22 	const size_t total_len = prefix_len + name_len + 1;
23 
24 	if (!capable(CAP_SYS_ADMIN))
25 		return 0;
26 
27 	if (list && total_len <= list_size) {
28 		memcpy(list, XATTR_TRUSTED_PREFIX, prefix_len);
29 		memcpy(list+prefix_len, name, name_len);
30 		list[prefix_len + name_len] = '\0';
31 	}
32 	return total_len;
33 }
34 
35 static int
36 ext2_xattr_trusted_get(struct inode *inode, const char *name,
37 		       void *buffer, size_t size)
38 {
39 	if (strcmp(name, "") == 0)
40 		return -EINVAL;
41 	return ext2_xattr_get(inode, EXT2_XATTR_INDEX_TRUSTED, name,
42 			      buffer, size);
43 }
44 
45 static int
46 ext2_xattr_trusted_set(struct inode *inode, const char *name,
47 		       const void *value, size_t size, int flags)
48 {
49 	if (strcmp(name, "") == 0)
50 		return -EINVAL;
51 	return ext2_xattr_set(inode, EXT2_XATTR_INDEX_TRUSTED, name,
52 			      value, size, flags);
53 }
54 
55 struct xattr_handler ext2_xattr_trusted_handler = {
56 	.prefix	= XATTR_TRUSTED_PREFIX,
57 	.list	= ext2_xattr_trusted_list,
58 	.get	= ext2_xattr_trusted_get,
59 	.set	= ext2_xattr_trusted_set,
60 };
61