Line data Source code
1 : /*
2 : * linux/fs/ext2/xattr_security.c
3 : * Handler for storing security labels as extended attributes.
4 : */
5 :
6 : #include <linux/module.h>
7 : #include <linux/string.h>
8 : #include <linux/fs.h>
9 : #include <linux/ext2_fs.h>
10 : #include <linux/security.h>
11 : #include "xattr.h"
12 :
13 : static size_t
14 : ext2_xattr_security_list(struct dentry *dentry, char *list, size_t list_size,
15 : const char *name, size_t name_len, int type)
16 : {
17 2 : const int prefix_len = XATTR_SECURITY_PREFIX_LEN;
18 2 : const size_t total_len = prefix_len + name_len + 1;
19 :
20 4 : if (list && total_len <= list_size) {
21 1 : memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
22 1 : memcpy(list+prefix_len, name, name_len);
23 1 : list[prefix_len + name_len] = '\0';
24 : }
25 1 : return total_len;
26 : }
27 :
28 : static int
29 : ext2_xattr_security_get(struct dentry *dentry, const char *name,
30 : void *buffer, size_t size, int type)
31 : {
32 4 : if (strcmp(name, "") == 0)
33 2 : return -EINVAL;
34 4 : return ext2_xattr_get(dentry->d_inode, EXT2_XATTR_INDEX_SECURITY, name,
35 : buffer, size);
36 : }
37 :
38 : static int
39 : ext2_xattr_security_set(struct dentry *dentry, const char *name,
40 : const void *value, size_t size, int flags, int type)
41 : {
42 4 : if (strcmp(name, "") == 0)
43 2 : return -EINVAL;
44 4 : return ext2_xattr_set(dentry->d_inode, EXT2_XATTR_INDEX_SECURITY, name,
45 : value, size, flags);
46 : }
47 :
48 : int
49 : ext2_init_security(struct inode *inode, struct inode *dir)
50 : {
51 16 : int err;
52 16 : size_t len;
53 16 : void *value;
54 16 : char *name;
55 :
56 32 : err = security_inode_init_security(inode, dir, &name, &value, &len);
57 32 : if (err) {
58 32 : if (err == -EOPNOTSUPP)
59 16 : return 0;
60 16 : return err;
61 : }
62 48 : err = ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY,
63 : name, value, len, 0);
64 16 : kfree(name);
65 16 : kfree(value);
66 16 : return err;
67 : }
68 :
69 1 : struct xattr_handler ext2_xattr_security_handler = {
70 : .prefix = XATTR_SECURITY_PREFIX,
71 : .list = ext2_xattr_security_list,
72 : .get = ext2_xattr_security_get,
73 : .set = ext2_xattr_security_set,
74 : };
|