xref: /openbmc/linux/fs/reiserfs/xattr_security.c (revision f3539c12)
1 #include "reiserfs.h"
2 #include <linux/errno.h>
3 #include <linux/fs.h>
4 #include <linux/pagemap.h>
5 #include <linux/xattr.h>
6 #include <linux/slab.h>
7 #include "xattr.h"
8 #include <linux/security.h>
9 #include <linux/uaccess.h>
10 
11 static int
12 security_get(const struct xattr_handler *handler, struct dentry *unused,
13 	     struct inode *inode, const char *name, void *buffer, size_t size)
14 {
15 	if (IS_PRIVATE(inode))
16 		return -EPERM;
17 
18 	return reiserfs_xattr_get(inode, xattr_full_name(handler, name),
19 				  buffer, size);
20 }
21 
22 static int
23 security_set(const struct xattr_handler *handler, struct dentry *unused,
24 	     struct inode *inode, const char *name, const void *buffer,
25 	     size_t size, int flags)
26 {
27 	if (IS_PRIVATE(inode))
28 		return -EPERM;
29 
30 	return reiserfs_xattr_set(inode,
31 				  xattr_full_name(handler, name),
32 				  buffer, size, flags);
33 }
34 
35 static bool security_list(struct dentry *dentry)
36 {
37 	return !IS_PRIVATE(d_inode(dentry));
38 }
39 
40 /* Initializes the security context for a new inode and returns the number
41  * of blocks needed for the transaction. If successful, reiserfs_security
42  * must be released using reiserfs_security_free when the caller is done. */
43 int reiserfs_security_init(struct inode *dir, struct inode *inode,
44 			   const struct qstr *qstr,
45 			   struct reiserfs_security_handle *sec)
46 {
47 	int blocks = 0;
48 	int error;
49 
50 	sec->name = NULL;
51 
52 	/* Don't add selinux attributes on xattrs - they'll never get used */
53 	if (IS_PRIVATE(dir))
54 		return 0;
55 
56 	error = security_old_inode_init_security(inode, dir, qstr, &sec->name,
57 						 &sec->value, &sec->length);
58 	if (error) {
59 		if (error == -EOPNOTSUPP)
60 			error = 0;
61 
62 		sec->name = NULL;
63 		sec->value = NULL;
64 		sec->length = 0;
65 		return error;
66 	}
67 
68 	if (sec->length && reiserfs_xattrs_initialized(inode->i_sb)) {
69 		blocks = reiserfs_xattr_jcreate_nblocks(inode) +
70 			 reiserfs_xattr_nblocks(inode, sec->length);
71 		/* We don't want to count the directories twice if we have
72 		 * a default ACL. */
73 		REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
74 	}
75 	return blocks;
76 }
77 
78 int reiserfs_security_write(struct reiserfs_transaction_handle *th,
79 			    struct inode *inode,
80 			    struct reiserfs_security_handle *sec)
81 {
82 	int error;
83 	if (strlen(sec->name) < sizeof(XATTR_SECURITY_PREFIX))
84 		return -EINVAL;
85 
86 	error = reiserfs_xattr_set_handle(th, inode, sec->name, sec->value,
87 					  sec->length, XATTR_CREATE);
88 	if (error == -ENODATA || error == -EOPNOTSUPP)
89 		error = 0;
90 
91 	return error;
92 }
93 
94 void reiserfs_security_free(struct reiserfs_security_handle *sec)
95 {
96 	kfree(sec->name);
97 	kfree(sec->value);
98 	sec->name = NULL;
99 	sec->value = NULL;
100 }
101 
102 const struct xattr_handler reiserfs_xattr_security_handler = {
103 	.prefix = XATTR_SECURITY_PREFIX,
104 	.get = security_get,
105 	.set = security_set,
106 	.list = security_list,
107 };
108