xref: /linux/fs/ext2/xattr_security.c (revision c0e297dc61f8d4453e07afbea1fa8d0e67cd4a34)
1 /*
2  * linux/fs/ext2/xattr_security.c
3  * Handler for storing security labels as extended attributes.
4  */
5 
6 #include "ext2.h"
7 #include <linux/security.h>
8 #include "xattr.h"
9 
10 static size_t
11 ext2_xattr_security_list(struct dentry *dentry, char *list, size_t list_size,
12 			 const char *name, size_t name_len, int type)
13 {
14 	const int prefix_len = XATTR_SECURITY_PREFIX_LEN;
15 	const size_t total_len = prefix_len + name_len + 1;
16 
17 	if (list && total_len <= list_size) {
18 		memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
19 		memcpy(list+prefix_len, name, name_len);
20 		list[prefix_len + name_len] = '\0';
21 	}
22 	return total_len;
23 }
24 
25 static int
26 ext2_xattr_security_get(struct dentry *dentry, const char *name,
27 		       void *buffer, size_t size, int type)
28 {
29 	if (strcmp(name, "") == 0)
30 		return -EINVAL;
31 	return ext2_xattr_get(d_inode(dentry), EXT2_XATTR_INDEX_SECURITY, name,
32 			      buffer, size);
33 }
34 
35 static int
36 ext2_xattr_security_set(struct dentry *dentry, const char *name,
37 		const void *value, size_t size, int flags, int type)
38 {
39 	if (strcmp(name, "") == 0)
40 		return -EINVAL;
41 	return ext2_xattr_set(d_inode(dentry), EXT2_XATTR_INDEX_SECURITY, name,
42 			      value, size, flags);
43 }
44 
45 static int ext2_initxattrs(struct inode *inode, const struct xattr *xattr_array,
46 			   void *fs_info)
47 {
48 	const struct xattr *xattr;
49 	int err = 0;
50 
51 	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
52 		err = ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY,
53 				     xattr->name, xattr->value,
54 				     xattr->value_len, 0);
55 		if (err < 0)
56 			break;
57 	}
58 	return err;
59 }
60 
61 int
62 ext2_init_security(struct inode *inode, struct inode *dir,
63 		   const struct qstr *qstr)
64 {
65 	return security_inode_init_security(inode, dir, qstr,
66 					    &ext2_initxattrs, NULL);
67 }
68 
69 const 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