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
ext2_xattr_security_list(struct inode * inode,char * list,size_t list_size,const char * name,size_t name_len)14 ext2_xattr_security_list(struct inode *inode, char *list, size_t list_size,
15 const char *name, size_t name_len)
16 {
17 const int prefix_len = XATTR_SECURITY_PREFIX_LEN;
18 const size_t total_len = prefix_len + name_len + 1;
19
20 if (list && total_len <= list_size) {
21 memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
22 memcpy(list+prefix_len, name, name_len);
23 list[prefix_len + name_len] = '\0';
24 }
25 return total_len;
26 }
27
28 static int
ext2_xattr_security_get(struct inode * inode,const char * name,void * buffer,size_t size)29 ext2_xattr_security_get(struct inode *inode, const char *name,
30 void *buffer, size_t size)
31 {
32 if (strcmp(name, "") == 0)
33 return -EINVAL;
34 return ext2_xattr_get(inode, EXT2_XATTR_INDEX_SECURITY, name,
35 buffer, size);
36 }
37
38 static int
ext2_xattr_security_set(struct inode * inode,const char * name,const void * value,size_t size,int flags)39 ext2_xattr_security_set(struct inode *inode, const char *name,
40 const void *value, size_t size, int flags)
41 {
42 if (strcmp(name, "") == 0)
43 return -EINVAL;
44 return ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY, name,
45 value, size, flags);
46 }
47
48 int
ext2_init_security(struct inode * inode,struct inode * dir)49 ext2_init_security(struct inode *inode, struct inode *dir)
50 {
51 int err;
52 size_t len;
53 void *value;
54 char *name;
55
56 err = security_inode_init_security(inode, dir, &name, &value, &len);
57 if (err) {
58 if (err == -EOPNOTSUPP)
59 return 0;
60 return err;
61 }
62 err = ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY,
63 name, value, len, 0);
64 kfree(name);
65 kfree(value);
66 return err;
67 }
68
69 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 };
75