xref: /openbmc/linux/fs/ext2/xattr_security.c (revision 0f4630f3)
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(const struct xattr_handler *handler,
12 			 struct dentry *dentry, char *list, size_t list_size,
13 			 const char *name, size_t name_len)
14 {
15 	const int prefix_len = XATTR_SECURITY_PREFIX_LEN;
16 	const size_t total_len = prefix_len + name_len + 1;
17 
18 	if (list && total_len <= list_size) {
19 		memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
20 		memcpy(list+prefix_len, name, name_len);
21 		list[prefix_len + name_len] = '\0';
22 	}
23 	return total_len;
24 }
25 
26 static int
27 ext2_xattr_security_get(const struct xattr_handler *handler,
28 			struct dentry *dentry, const char *name,
29 			void *buffer, size_t size)
30 {
31 	if (strcmp(name, "") == 0)
32 		return -EINVAL;
33 	return ext2_xattr_get(d_inode(dentry), EXT2_XATTR_INDEX_SECURITY, name,
34 			      buffer, size);
35 }
36 
37 static int
38 ext2_xattr_security_set(const struct xattr_handler *handler,
39 			struct dentry *dentry, 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(d_inode(dentry), EXT2_XATTR_INDEX_SECURITY, name,
45 			      value, size, flags);
46 }
47 
48 static int ext2_initxattrs(struct inode *inode, const struct xattr *xattr_array,
49 			   void *fs_info)
50 {
51 	const struct xattr *xattr;
52 	int err = 0;
53 
54 	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
55 		err = ext2_xattr_set(inode, EXT2_XATTR_INDEX_SECURITY,
56 				     xattr->name, xattr->value,
57 				     xattr->value_len, 0);
58 		if (err < 0)
59 			break;
60 	}
61 	return err;
62 }
63 
64 int
65 ext2_init_security(struct inode *inode, struct inode *dir,
66 		   const struct qstr *qstr)
67 {
68 	return security_inode_init_security(inode, dir, qstr,
69 					    &ext2_initxattrs, NULL);
70 }
71 
72 const struct xattr_handler ext2_xattr_security_handler = {
73 	.prefix	= XATTR_SECURITY_PREFIX,
74 	.list	= ext2_xattr_security_list,
75 	.get	= ext2_xattr_security_get,
76 	.set	= ext2_xattr_security_set,
77 };
78