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1/*
2 * FUSE: Filesystem in Userspace
3 * Copyright (C) 2016 Canonical Ltd. <seth.forshee@canonical.com>
4 *
5 * This program can be distributed under the terms of the GNU GPL.
6 * See the file COPYING.
7 */
8
9#include "fuse_i.h"
10
11#include <linux/posix_acl.h>
12#include <linux/posix_acl_xattr.h>
13
14struct posix_acl *fuse_get_acl(struct inode *inode, int type)
15{
16 struct fuse_conn *fc = get_fuse_conn(inode);
17 int size;
18 const char *name;
19 void *value = NULL;
20 struct posix_acl *acl;
21
22 if (!fc->posix_acl || fc->no_getxattr)
23 return NULL;
24
25 if (type == ACL_TYPE_ACCESS)
26 name = XATTR_NAME_POSIX_ACL_ACCESS;
27 else if (type == ACL_TYPE_DEFAULT)
28 name = XATTR_NAME_POSIX_ACL_DEFAULT;
29 else
30 return ERR_PTR(-EOPNOTSUPP);
31
32 value = kmalloc(PAGE_SIZE, GFP_KERNEL);
33 if (!value)
34 return ERR_PTR(-ENOMEM);
35 size = fuse_getxattr(inode, name, value, PAGE_SIZE);
36 if (size > 0)
37 acl = posix_acl_from_xattr(&init_user_ns, value, size);
38 else if ((size == 0) || (size == -ENODATA) ||
39 (size == -EOPNOTSUPP && fc->no_getxattr))
40 acl = NULL;
41 else if (size == -ERANGE)
42 acl = ERR_PTR(-E2BIG);
43 else
44 acl = ERR_PTR(size);
45
46 kfree(value);
47 return acl;
48}
49
50int fuse_set_acl(struct inode *inode, struct posix_acl *acl, int type)
51{
52 struct fuse_conn *fc = get_fuse_conn(inode);
53 const char *name;
54 int ret;
55
56 if (!fc->posix_acl || fc->no_setxattr)
57 return -EOPNOTSUPP;
58
59 if (type == ACL_TYPE_ACCESS)
60 name = XATTR_NAME_POSIX_ACL_ACCESS;
61 else if (type == ACL_TYPE_DEFAULT)
62 name = XATTR_NAME_POSIX_ACL_DEFAULT;
63 else
64 return -EINVAL;
65
66 if (acl) {
67 /*
68 * Fuse userspace is responsible for updating access
69 * permissions in the inode, if needed. fuse_setxattr
70 * invalidates the inode attributes, which will force
71 * them to be refreshed the next time they are used,
72 * and it also updates i_ctime.
73 */
74 size_t size = posix_acl_xattr_size(acl->a_count);
75 void *value;
76
77 if (size > PAGE_SIZE)
78 return -E2BIG;
79
80 value = kmalloc(size, GFP_KERNEL);
81 if (!value)
82 return -ENOMEM;
83
84 ret = posix_acl_to_xattr(&init_user_ns, acl, value, size);
85 if (ret < 0) {
86 kfree(value);
87 return ret;
88 }
89
90 ret = fuse_setxattr(inode, name, value, size, 0);
91 kfree(value);
92 } else {
93 ret = fuse_removexattr(inode, name);
94 }
95 forget_all_cached_acls(inode);
96 fuse_invalidate_attr(inode);
97
98 return ret;
99}
1/*
2 * FUSE: Filesystem in Userspace
3 * Copyright (C) 2016 Canonical Ltd. <seth.forshee@canonical.com>
4 *
5 * This program can be distributed under the terms of the GNU GPL.
6 * See the file COPYING.
7 */
8
9#include "fuse_i.h"
10
11#include <linux/posix_acl.h>
12#include <linux/posix_acl_xattr.h>
13
14struct posix_acl *fuse_get_acl(struct inode *inode, int type)
15{
16 struct fuse_conn *fc = get_fuse_conn(inode);
17 int size;
18 const char *name;
19 void *value = NULL;
20 struct posix_acl *acl;
21
22 if (fuse_is_bad(inode))
23 return ERR_PTR(-EIO);
24
25 if (!fc->posix_acl || fc->no_getxattr)
26 return NULL;
27
28 if (type == ACL_TYPE_ACCESS)
29 name = XATTR_NAME_POSIX_ACL_ACCESS;
30 else if (type == ACL_TYPE_DEFAULT)
31 name = XATTR_NAME_POSIX_ACL_DEFAULT;
32 else
33 return ERR_PTR(-EOPNOTSUPP);
34
35 value = kmalloc(PAGE_SIZE, GFP_KERNEL);
36 if (!value)
37 return ERR_PTR(-ENOMEM);
38 size = fuse_getxattr(inode, name, value, PAGE_SIZE);
39 if (size > 0)
40 acl = posix_acl_from_xattr(fc->user_ns, value, size);
41 else if ((size == 0) || (size == -ENODATA) ||
42 (size == -EOPNOTSUPP && fc->no_getxattr))
43 acl = NULL;
44 else if (size == -ERANGE)
45 acl = ERR_PTR(-E2BIG);
46 else
47 acl = ERR_PTR(size);
48
49 kfree(value);
50 return acl;
51}
52
53int fuse_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
54 struct posix_acl *acl, int type)
55{
56 struct fuse_conn *fc = get_fuse_conn(inode);
57 const char *name;
58 int ret;
59
60 if (fuse_is_bad(inode))
61 return -EIO;
62
63 if (!fc->posix_acl || fc->no_setxattr)
64 return -EOPNOTSUPP;
65
66 if (type == ACL_TYPE_ACCESS)
67 name = XATTR_NAME_POSIX_ACL_ACCESS;
68 else if (type == ACL_TYPE_DEFAULT)
69 name = XATTR_NAME_POSIX_ACL_DEFAULT;
70 else
71 return -EINVAL;
72
73 if (acl) {
74 unsigned int extra_flags = 0;
75 /*
76 * Fuse userspace is responsible for updating access
77 * permissions in the inode, if needed. fuse_setxattr
78 * invalidates the inode attributes, which will force
79 * them to be refreshed the next time they are used,
80 * and it also updates i_ctime.
81 */
82 size_t size = posix_acl_xattr_size(acl->a_count);
83 void *value;
84
85 if (size > PAGE_SIZE)
86 return -E2BIG;
87
88 value = kmalloc(size, GFP_KERNEL);
89 if (!value)
90 return -ENOMEM;
91
92 ret = posix_acl_to_xattr(fc->user_ns, acl, value, size);
93 if (ret < 0) {
94 kfree(value);
95 return ret;
96 }
97
98 if (!in_group_p(i_gid_into_mnt(&init_user_ns, inode)) &&
99 !capable_wrt_inode_uidgid(&init_user_ns, inode, CAP_FSETID))
100 extra_flags |= FUSE_SETXATTR_ACL_KILL_SGID;
101
102 ret = fuse_setxattr(inode, name, value, size, 0, extra_flags);
103 kfree(value);
104 } else {
105 ret = fuse_removexattr(inode, name);
106 }
107 forget_all_cached_acls(inode);
108 fuse_invalidate_attr(inode);
109
110 return ret;
111}