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
16 static size_t
ext4_xattr_trusted_list(struct dentry * dentry,char * list,size_t list_size,const char * name,size_t name_len,int type)17 ext4_xattr_trusted_list(struct dentry *dentry, char *list, size_t list_size,
18 const char *name, size_t name_len, int type)
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
34 static int
ext4_xattr_trusted_get(struct dentry * dentry,const char * name,void * buffer,size_t size,int type)35 ext4_xattr_trusted_get(struct dentry *dentry, const char *name, void *buffer,
36 size_t size, int type)
37 {
38 if (strcmp(name, "") == 0)
39 return -EINVAL;
40 return ext4_xattr_get(dentry->d_inode, EXT4_XATTR_INDEX_TRUSTED,
41 name, buffer, size);
42 }
43
44 static int
ext4_xattr_trusted_set(struct dentry * dentry,const char * name,const void * value,size_t size,int flags,int type)45 ext4_xattr_trusted_set(struct dentry *dentry, const char *name,
46 const void *value, size_t size, int flags, int type)
47 {
48 if (strcmp(name, "") == 0)
49 return -EINVAL;
50 return ext4_xattr_set(dentry->d_inode, EXT4_XATTR_INDEX_TRUSTED,
51 name, value, size, flags);
52 }
53
54 const struct 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