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
14 static size_t
ext2_xattr_security_list(struct dentry * dentry,char * list,size_t list_size,const char * name,size_t name_len,int type)15 ext2_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
29 static int
ext2_xattr_security_get(struct dentry * dentry,const char * name,void * buffer,size_t size,int type)30 ext2_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
39 static int
ext2_xattr_security_set(struct dentry * dentry,const char * name,const void * value,size_t size,int flags,int type)40 ext2_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
49 int
ext2_init_security(struct inode * inode,struct inode * dir,const struct qstr * qstr)50 ext2_init_security(struct inode *inode, struct inode *dir,
51 const struct qstr *qstr)
52 {
53 int err;
54 size_t len;
55 void *value;
56 char *name;
57
58 err = security_inode_init_security(inode, dir, qstr, &name, &value, &len);
59 if (err) {
60 if (err == -EOPNOTSUPP)
61 return 0;
62 return err;
63 }
64 err = ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY,
65 name, value, len, 0);
66 kfree(name);
67 kfree(value);
68 return err;
69 }
70
71 const struct xattr_handler ext2_xattr_security_handler = {
72 .prefix = XATTR_SECURITY_PREFIX,
73 .list = ext2_xattr_security_list,
74 .get = ext2_xattr_security_get,
75 .set = ext2_xattr_security_set,
76 };
77