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/slab.h>
8#include <linux/string.h>
9#include <linux/fs.h>
10#include <linux/ext2_fs.h>
11#include <linux/security.h>
12#include "xattr.h"
13
14static size_t
15ext2_xattr_security_list(struct dentry *dentry, char *list, size_t list_size,
16			 const char *name, size_t name_len, int type)
17{
18	const int prefix_len = XATTR_SECURITY_PREFIX_LEN;
19	const size_t total_len = prefix_len + name_len + 1;
20
21	if (list && total_len <= list_size) {
22		memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
23		memcpy(list+prefix_len, name, name_len);
24		list[prefix_len + name_len] = '\0';
25	}
26	return total_len;
27}
28
29static int
30ext2_xattr_security_get(struct dentry *dentry, const char *name,
31		       void *buffer, size_t size, int type)
32{
33	if (strcmp(name, "") == 0)
34		return -EINVAL;
35	return ext2_xattr_get(dentry->d_inode, EXT2_XATTR_INDEX_SECURITY, name,
36			      buffer, size);
37}
38
39static int
40ext2_xattr_security_set(struct dentry *dentry, const char *name,
41		const void *value, size_t size, int flags, int type)
42{
43	if (strcmp(name, "") == 0)
44		return -EINVAL;
45	return ext2_xattr_set(dentry->d_inode, EXT2_XATTR_INDEX_SECURITY, name,
46			      value, size, flags);
47}
48
49int
50ext2_init_security(struct inode *inode, struct inode *dir)
51{
52	int err;
53	size_t len;
54	void *value;
55	char *name;
56
57	err = security_inode_init_security(inode, dir, &name, &value, &len);
58	if (err) {
59		if (err == -EOPNOTSUPP)
60			return 0;
61		return err;
62	}
63	err = ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY,
64			     name, value, len, 0);
65	kfree(name);
66	kfree(value);
67	return err;
68}
69
70const struct xattr_handler ext2_xattr_security_handler = {
71	.prefix	= XATTR_SECURITY_PREFIX,
72	.list	= ext2_xattr_security_list,
73	.get	= ext2_xattr_security_get,
74	.set	= ext2_xattr_security_set,
75};
76