ext3: ensure fast symlinks are NUL-terminated
[linux-2.6.git] / fs / ext3 / xattr_trusted.c
1 /*
2  * linux/fs/ext3/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/ext3_jbd.h>
13 #include <linux/ext3_fs.h>
14 #include "xattr.h"
15
16 static size_t
17 ext3_xattr_trusted_list(struct inode *inode, char *list, size_t list_size,
18                         const char *name, size_t name_len)
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
35 ext3_xattr_trusted_get(struct inode *inode, const char *name,
36                        void *buffer, size_t size)
37 {
38         if (strcmp(name, "") == 0)
39                 return -EINVAL;
40         return ext3_xattr_get(inode, EXT3_XATTR_INDEX_TRUSTED, name,
41                               buffer, size);
42 }
43
44 static int
45 ext3_xattr_trusted_set(struct inode *inode, const char *name,
46                        const void *value, size_t size, int flags)
47 {
48         if (strcmp(name, "") == 0)
49                 return -EINVAL;
50         return ext3_xattr_set(inode, EXT3_XATTR_INDEX_TRUSTED, name,
51                               value, size, flags);
52 }
53
54 struct xattr_handler ext3_xattr_trusted_handler = {
55         .prefix = XATTR_TRUSTED_PREFIX,
56         .list   = ext3_xattr_trusted_list,
57         .get    = ext3_xattr_trusted_get,
58         .set    = ext3_xattr_trusted_set,
59 };