1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
/*
* fs/generic_acl.c
*
* (C) 2005 Andreas Gruenbacher <agruen@suse.de>
*
* This file is released under the GPL.
*/
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/generic_acl.h>
/**
* generic_acl_list - Generic xattr_handler->list() operation
* @ops: Filesystem specific getacl and setacl callbacks
*/
size_t
generic_acl_list(struct inode *inode, struct generic_acl_operations *ops,
int type, char *list, size_t list_size)
{
struct posix_acl *acl;
const char *name;
size_t size;
acl = ops->getacl(inode, type);
if (!acl)
return 0;
posix_acl_release(acl);
switch(type) {
case ACL_TYPE_ACCESS:
name = POSIX_ACL_XATTR_ACCESS;
break;
case ACL_TYPE_DEFAULT:
name = POSIX_ACL_XATTR_DEFAULT;
break;
default:
return 0;
}
size = strlen(name) + 1;
if (list && size <= list_size)
memcpy(list, name, size);
return size;
}
/**
* generic_acl_get - Generic xattr_handler->get() operation
* @ops: Filesystem specific getacl and setacl callbacks
*/
int
generic_acl_get(struct inode *inode, struct generic_acl_operations *ops,
int type, void *buffer, size_t size)
{
struct posix_acl *acl;
int error;
acl = ops->getacl(inode, type);
if (!acl)
return -ENODATA;
error = posix_acl_to_xattr(acl, buffer, size);
posix_acl_release(acl);
return error;
}
/**
* generic_acl_set - Generic xattr_handler->set() operation
* @ops: Filesystem specific getacl and setacl callbacks
*/
int
generic_acl_set(struct inode *inode, struct generic_acl_operations *ops,
int type, const void *value, size_t size)
{
struct posix_acl *acl = NULL;
int error;
if (S_ISLNK(inode->i_mode))
return -EOPNOTSUPP;
if (current->fsuid != inode->i_uid && !capable(CAP_FOWNER))
return -EPERM;
if (value) {
acl = posix_acl_from_xattr(value, size);
if (IS_ERR(acl))
return PTR_ERR(acl);
}
if (acl) {
mode_t mode;
error = posix_acl_valid(acl);
if (error)
goto failed;
switch(type) {
case ACL_TYPE_ACCESS:
mode = inode->i_mode;
error = posix_acl_equiv_mode(acl, &mode);
if (error < 0)
goto failed;
inode->i_mode = mode;
if (error == 0) {
posix_acl_release(acl);
acl = NULL;
}
break;
case ACL_TYPE_DEFAULT:
if (!S_ISDIR(inode->i_mode)) {
error = -EINVAL;
goto failed;
}
break;
}
}
ops->setacl(inode, type, acl);
error = 0;
failed:
posix_acl_release(acl);
return error;
}
/**
* generic_acl_init - Take care of acl inheritance at @inode create time
* @ops: Filesystem specific getacl and setacl callbacks
*
* Files created inside a directory with a default ACL inherit the
* directory's default ACL.
*/
int
generic_acl_init(struct inode *inode, struct inode *dir,
struct generic_acl_operations *ops)
{
struct posix_acl *acl = NULL;
mode_t mode = inode->i_mode;
int error;
inode->i_mode = mode & ~current->fs->umask;
if (!S_ISLNK(inode->i_mode))
acl = ops->getacl(dir, ACL_TYPE_DEFAULT);
if (acl) {
struct posix_acl *clone;
if (S_ISDIR(inode->i_mode)) {
clone = posix_acl_clone(acl, GFP_KERNEL);
error = -ENOMEM;
if (!clone)
goto cleanup;
ops->setacl(inode, ACL_TYPE_DEFAULT, clone);
posix_acl_release(clone);
}
clone = posix_acl_clone(acl, GFP_KERNEL);
error = -ENOMEM;
if (!clone)
goto cleanup;
error = posix_acl_create_masq(clone, &mode);
if (error >= 0) {
inode->i_mode = mode;
if (error > 0)
ops->setacl(inode, ACL_TYPE_ACCESS, clone);
}
posix_acl_release(clone);
}
error = 0;
cleanup:
posix_acl_release(acl);
return error;
}
/**
* generic_acl_chmod - change the access acl of @inode upon chmod()
* @ops: FIlesystem specific getacl and setacl callbacks
*
* A chmod also changes the permissions of the owner, group/mask, and
* other ACL entries.
*/
int
generic_acl_chmod(struct inode *inode, struct generic_acl_operations *ops)
{
struct posix_acl *acl, *clone;
int error = 0;
if (S_ISLNK(inode->i_mode))
return -EOPNOTSUPP;
acl = ops->getacl(inode, ACL_TYPE_ACCESS);
if (acl) {
clone = posix_acl_clone(acl, GFP_KERNEL);
posix_acl_release(acl);
if (!clone)
return -ENOMEM;
error = posix_acl_chmod_masq(clone, inode->i_mode);
if (!error)
ops->setacl(inode, ACL_TYPE_ACCESS, clone);
posix_acl_release(clone);
}
return error;
}
|
