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
|
/*
* Copyright (C) 2018 Canonical Ltd
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 3 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#define _GNU_SOURCE
#include "feature.h"
#include <errno.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include "cleanup-funcs.h"
#include "utils.h"
static const char *feature_flag_dir = "/var/lib/snapd/features";
bool sc_feature_enabled(sc_feature_flag flag) {
const char *file_name;
switch (flag) {
case SC_FEATURE_PER_USER_MOUNT_NAMESPACE:
file_name = "per-user-mount-namespace";
break;
case SC_FEATURE_REFRESH_APP_AWARENESS:
file_name = "refresh-app-awareness";
break;
case SC_FEATURE_PARALLEL_INSTANCES:
file_name = "parallel-instances";
break;
case SC_FEATURE_HIDDEN_SNAP_FOLDER:
file_name = "hidden-snap-folder";
break;
default:
die("unknown feature flag code %d", flag);
}
int dirfd SC_CLEANUP(sc_cleanup_close) = -1;
dirfd = open(feature_flag_dir, O_CLOEXEC | O_DIRECTORY | O_NOFOLLOW | O_PATH);
if (dirfd < 0 && errno == ENOENT) {
return false;
}
if (dirfd < 0) {
die("cannot open path %s", feature_flag_dir);
}
struct stat file_info;
if (fstatat(dirfd, file_name, &file_info, AT_SYMLINK_NOFOLLOW) < 0) {
if (errno == ENOENT) {
return false;
}
die("cannot inspect file %s/%s", feature_flag_dir, file_name);
}
return S_ISREG(file_info.st_mode);
}
|
