1/*
 2 * linux/fs/ext4/xattr_security.c
 3 * Handler for storing security labels as extended attributes.
 4 */
 5
 6#include <linux/module.h>
 7#include <linux/string.h>
 8#include <linux/fs.h>
 9#include <linux/security.h>
10#include <linux/slab.h>
11#include "ext4_jbd2.h"
12#include "ext4.h"
13#include "xattr.h"
14
15static size_t
16ext4_xattr_security_list(struct dentry *dentry, char *list, size_t list_size,
17		const char *name, size_t name_len, int type)
 
18{
19	const size_t prefix_len = sizeof(XATTR_SECURITY_PREFIX)-1;
20	const size_t total_len = prefix_len + name_len + 1;
21
22
23	if (list && total_len <= list_size) {
24		memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
25		memcpy(list+prefix_len, name, name_len);
26		list[prefix_len + name_len] = '\0';
27	}
28	return total_len;
29}
30
31static int
32ext4_xattr_security_get(struct dentry *dentry, const char *name,
33		       void *buffer, size_t size, int type)
 
 
 
34{
35	if (strcmp(name, "") == 0)
36		return -EINVAL;
37	return ext4_xattr_get(dentry->d_inode, EXT4_XATTR_INDEX_SECURITY,
38			      name, buffer, size);
39}
40
41static int
42ext4_xattr_security_set(struct dentry *dentry, const char *name,
43		const void *value, size_t size, int flags, int type)
44{
45	if (strcmp(name, "") == 0)
46		return -EINVAL;
47	return ext4_xattr_set(dentry->d_inode, EXT4_XATTR_INDEX_SECURITY,
48			      name, value, size, flags);
 
 
 
 
 
 
 
 
 
49}
50
51int
52ext4_init_security(handle_t *handle, struct inode *inode, struct inode *dir,
53		   const struct qstr *qstr)
54{
55	int err;
56	size_t len;
57	void *value;
58	char *name;
59
60	err = security_inode_init_security(inode, dir, qstr, &name, &value, &len);
61	if (err) {
62		if (err == -EOPNOTSUPP)
63			return 0;
64		return err;
65	}
66	err = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_SECURITY,
67				    name, value, len, 0);
68	kfree(name);
69	kfree(value);
70	return err;
71}
72
73const struct xattr_handler ext4_xattr_security_handler = {
74	.prefix	= XATTR_SECURITY_PREFIX,
75	.list	= ext4_xattr_security_list,
76	.get	= ext4_xattr_security_get,
77	.set	= ext4_xattr_security_set,
78};

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * linux/fs/ext4/xattr_security.c
 4 * Handler for storing security labels as extended attributes.
 5 */
 6
 
 7#include <linux/string.h>
 8#include <linux/fs.h>
 9#include <linux/security.h>
10#include <linux/slab.h>
11#include "ext4_jbd2.h"
12#include "ext4.h"
13#include "xattr.h"
14
15static int
16ext4_xattr_security_get(const struct xattr_handler *handler,
17			struct dentry *unused, struct inode *inode,
18			const char *name, void *buffer, size_t size)
19{
20	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_SECURITY,
21			      name, buffer, size);
 
 
 
 
 
 
 
 
22}
23
24static int
25ext4_xattr_security_set(const struct xattr_handler *handler,
26			struct user_namespace *mnt_userns,
27			struct dentry *unused, struct inode *inode,
28			const char *name, const void *value,
29			size_t size, int flags)
30{
31	return ext4_xattr_set(inode, EXT4_XATTR_INDEX_SECURITY,
32			      name, value, size, flags);
 
 
33}
34
35static int
36ext4_initxattrs(struct inode *inode, const struct xattr *xattr_array,
37		void *fs_info)
38{
39	const struct xattr *xattr;
40	handle_t *handle = fs_info;
41	int err = 0;
42
43	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
44		err = ext4_xattr_set_handle(handle, inode,
45					    EXT4_XATTR_INDEX_SECURITY,
46					    xattr->name, xattr->value,
47					    xattr->value_len, XATTR_CREATE);
48		if (err < 0)
49			break;
50	}
51	return err;
52}
53
54int
55ext4_init_security(handle_t *handle, struct inode *inode, struct inode *dir,
56		   const struct qstr *qstr)
57{
58	return security_inode_init_security(inode, dir, qstr,
59					    &ext4_initxattrs, handle);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
60}
61
62const struct xattr_handler ext4_xattr_security_handler = {
63	.prefix	= XATTR_SECURITY_PREFIX,
 
64	.get	= ext4_xattr_security_get,
65	.set	= ext4_xattr_security_set,
66};