Merge branch 'for_linus' into for_linus_merged
[linux-2.6.git] / fs / ext4 / xattr_security.c
1 /*
2  * linux/fs/ext4/xattr_security.c
3  * Handler for storing security labels as extended attributes.
4  */
5
6 #include <linux/string.h>
7 #include <linux/fs.h>
8 #include <linux/security.h>
9 #include <linux/slab.h>
10 #include "ext4_jbd2.h"
11 #include "ext4.h"
12 #include "xattr.h"
13
14 static size_t
15 ext4_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 size_t prefix_len = sizeof(XATTR_SECURITY_PREFIX)-1;
19         const size_t total_len = prefix_len + name_len + 1;
20
21
22         if (list && total_len <= list_size) {
23                 memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
24                 memcpy(list+prefix_len, name, name_len);
25                 list[prefix_len + name_len] = '\0';
26         }
27         return total_len;
28 }
29
30 static int
31 ext4_xattr_security_get(struct dentry *dentry, const char *name,
32                        void *buffer, size_t size, int type)
33 {
34         if (strcmp(name, "") == 0)
35                 return -EINVAL;
36         return ext4_xattr_get(dentry->d_inode, EXT4_XATTR_INDEX_SECURITY,
37                               name, buffer, size);
38 }
39
40 static int
41 ext4_xattr_security_set(struct dentry *dentry, const char *name,
42                 const void *value, size_t size, int flags, int type)
43 {
44         if (strcmp(name, "") == 0)
45                 return -EINVAL;
46         return ext4_xattr_set(dentry->d_inode, EXT4_XATTR_INDEX_SECURITY,
47                               name, value, size, flags);
48 }
49
50 static int
51 ext4_initxattrs(struct inode *inode, const struct xattr *xattr_array,
52                 void *fs_info)
53 {
54         const struct xattr *xattr;
55         handle_t *handle = fs_info;
56         int err = 0;
57
58         for (xattr = xattr_array; xattr->name != NULL; xattr++) {
59                 err = ext4_xattr_set_handle(handle, inode,
60                                             EXT4_XATTR_INDEX_SECURITY,
61                                             xattr->name, xattr->value,
62                                             xattr->value_len, 0);
63                 if (err < 0)
64                         break;
65         }
66         return err;
67 }
68
69 int
70 ext4_init_security(handle_t *handle, struct inode *inode, struct inode *dir,
71                    const struct qstr *qstr)
72 {
73         return security_inode_init_security(inode, dir, qstr,
74                                             &ext4_initxattrs, handle);
75 }
76
77 const struct xattr_handler ext4_xattr_security_handler = {
78         .prefix = XATTR_SECURITY_PREFIX,
79         .list   = ext4_xattr_security_list,
80         .get    = ext4_xattr_security_get,
81         .set    = ext4_xattr_security_set,
82 };