GNU Linux-libre 4.19.211-gnu1
[releases.git] / fs / reiserfs / xattr_security.c
1 // SPDX-License-Identifier: GPL-2.0
2 #include "reiserfs.h"
3 #include <linux/errno.h>
4 #include <linux/fs.h>
5 #include <linux/pagemap.h>
6 #include <linux/xattr.h>
7 #include <linux/slab.h>
8 #include "xattr.h"
9 #include <linux/security.h>
10 #include <linux/uaccess.h>
11
12 static int
13 security_get(const struct xattr_handler *handler, struct dentry *unused,
14              struct inode *inode, const char *name, void *buffer, size_t size)
15 {
16         if (IS_PRIVATE(inode))
17                 return -EPERM;
18
19         return reiserfs_xattr_get(inode, xattr_full_name(handler, name),
20                                   buffer, size);
21 }
22
23 static int
24 security_set(const struct xattr_handler *handler, struct dentry *unused,
25              struct inode *inode, const char *name, const void *buffer,
26              size_t size, int flags)
27 {
28         if (IS_PRIVATE(inode))
29                 return -EPERM;
30
31         return reiserfs_xattr_set(inode,
32                                   xattr_full_name(handler, name),
33                                   buffer, size, flags);
34 }
35
36 static bool security_list(struct dentry *dentry)
37 {
38         return !IS_PRIVATE(d_inode(dentry));
39 }
40
41 /* Initializes the security context for a new inode and returns the number
42  * of blocks needed for the transaction. If successful, reiserfs_security
43  * must be released using reiserfs_security_free when the caller is done. */
44 int reiserfs_security_init(struct inode *dir, struct inode *inode,
45                            const struct qstr *qstr,
46                            struct reiserfs_security_handle *sec)
47 {
48         int blocks = 0;
49         int error;
50
51         sec->name = NULL;
52
53         /* Don't add selinux attributes on xattrs - they'll never get used */
54         if (IS_PRIVATE(dir))
55                 return 0;
56
57         error = security_old_inode_init_security(inode, dir, qstr, &sec->name,
58                                                  &sec->value, &sec->length);
59         if (error) {
60                 if (error == -EOPNOTSUPP)
61                         error = 0;
62
63                 sec->name = NULL;
64                 sec->value = NULL;
65                 sec->length = 0;
66                 return error;
67         }
68
69         if (sec->length && reiserfs_xattrs_initialized(inode->i_sb)) {
70                 blocks = reiserfs_xattr_jcreate_nblocks(inode) +
71                          reiserfs_xattr_nblocks(inode, sec->length);
72                 /* We don't want to count the directories twice if we have
73                  * a default ACL. */
74                 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
75         }
76         return blocks;
77 }
78
79 int reiserfs_security_write(struct reiserfs_transaction_handle *th,
80                             struct inode *inode,
81                             struct reiserfs_security_handle *sec)
82 {
83         int error;
84         if (strlen(sec->name) < sizeof(XATTR_SECURITY_PREFIX))
85                 return -EINVAL;
86
87         error = reiserfs_xattr_set_handle(th, inode, sec->name, sec->value,
88                                           sec->length, XATTR_CREATE);
89         if (error == -ENODATA || error == -EOPNOTSUPP)
90                 error = 0;
91
92         return error;
93 }
94
95 void reiserfs_security_free(struct reiserfs_security_handle *sec)
96 {
97         kfree(sec->name);
98         kfree(sec->value);
99         sec->name = NULL;
100         sec->value = NULL;
101 }
102
103 const struct xattr_handler reiserfs_xattr_security_handler = {
104         .prefix = XATTR_SECURITY_PREFIX,
105         .get = security_get,
106         .set = security_set,
107         .list = security_list,
108 };