1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 This file is part of systemd.
5 Copyright 2010-2012 Lennart Poettering
7 systemd is free software; you can redistribute it and/or modify it
8 under the terms of the GNU Lesser General Public License as published by
9 the Free Software Foundation; either version 2.1 of the License, or
10 (at your option) any later version.
12 systemd is distributed in the hope that it will be useful, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Lesser General Public License for more details.
17 You should have received a copy of the GNU Lesser General Public License
18 along with systemd; If not, see <http://www.gnu.org/licenses/>.
25 #include <sys/types.h>
26 #include <linux/magic.h>
27 #include <sys/statvfs.h>
30 #include "dirent-util.h"
35 #include "stat-util.h"
36 #include "string-util.h"
38 int is_symlink(const char *path
) {
43 if (lstat(path
, &info
) < 0)
46 return !!S_ISLNK(info
.st_mode
);
49 int is_dir(const char* path
, bool follow
) {
62 return !!S_ISDIR(st
.st_mode
);
65 int is_device_node(const char *path
) {
70 if (lstat(path
, &info
) < 0)
73 return !!(S_ISBLK(info
.st_mode
) || S_ISCHR(info
.st_mode
));
76 int dir_is_empty(const char *path
) {
77 _cleanup_closedir_
DIR *d
;
84 FOREACH_DIRENT(de
, d
, return -errno
)
90 bool null_or_empty(struct stat
*st
) {
93 if (S_ISREG(st
->st_mode
) && st
->st_size
<= 0)
96 /* We don't want to hardcode the major/minor of /dev/null,
97 * hence we do a simpler "is this a device node?" check. */
99 if (S_ISCHR(st
->st_mode
) || S_ISBLK(st
->st_mode
))
105 int null_or_empty_path(const char *fn
) {
110 if (stat(fn
, &st
) < 0)
113 return null_or_empty(&st
);
116 int null_or_empty_fd(int fd
) {
121 if (fstat(fd
, &st
) < 0)
124 return null_or_empty(&st
);
127 int path_is_read_only_fs(const char *path
) {
132 if (statvfs(path
, &st
) < 0)
135 if (st
.f_flag
& ST_RDONLY
)
138 /* On NFS, statvfs() might not reflect whether we can actually
139 * write to the remote share. Let's try again with
140 * access(W_OK) which is more reliable, at least sometimes. */
141 if (access(path
, W_OK
) < 0 && errno
== EROFS
)
147 int path_is_os_tree(const char *path
) {
152 /* Does the path exist at all? If not, generate an error immediately. This is useful so that a missing root dir
153 * always results in -ENOENT, and we can properly distuingish the case where the whole root doesn't exist from
154 * the case where just the os-release file is missing. */
155 if (laccess(path
, F_OK
) < 0)
158 /* We use /usr/lib/os-release as flag file if something is an OS */
159 r
= chase_symlinks("/usr/lib/os-release", path
, CHASE_PREFIX_ROOT
, NULL
);
162 /* Also check for the old location in /etc, just in case. */
163 r
= chase_symlinks("/etc/os-release", path
, CHASE_PREFIX_ROOT
, NULL
);
165 return 0; /* We got nothing */
173 int files_same(const char *filea
, const char *fileb
, int flags
) {
179 if (fstatat(AT_FDCWD
, filea
, &a
, flags
) < 0)
182 if (fstatat(AT_FDCWD
, fileb
, &b
, flags
) < 0)
185 return a
.st_dev
== b
.st_dev
&&
186 a
.st_ino
== b
.st_ino
;
189 bool is_fs_type(const struct statfs
*s
, statfs_f_type_t magic_value
) {
191 assert_cc(sizeof(statfs_f_type_t
) >= sizeof(s
->f_type
));
193 return F_TYPE_EQUAL(s
->f_type
, magic_value
);
196 int fd_is_fs_type(int fd
, statfs_f_type_t magic_value
) {
199 if (fstatfs(fd
, &s
) < 0)
202 return is_fs_type(&s
, magic_value
);
205 int path_is_fs_type(const char *path
, statfs_f_type_t magic_value
) {
206 _cleanup_close_
int fd
= -1;
208 fd
= open(path
, O_RDONLY
|O_CLOEXEC
|O_NOCTTY
|O_PATH
);
212 return fd_is_fs_type(fd
, magic_value
);
215 bool is_temporary_fs(const struct statfs
*s
) {
216 return is_fs_type(s
, TMPFS_MAGIC
) ||
217 is_fs_type(s
, RAMFS_MAGIC
);
220 int fd_is_temporary_fs(int fd
) {
223 if (fstatfs(fd
, &s
) < 0)
226 return is_temporary_fs(&s
);
229 int fd_is_network_ns(int fd
) {
232 r
= fd_is_fs_type(fd
, NSFS_MAGIC
);
235 r
= ioctl(fd
, NS_GET_NSTYPE
);
238 return r
== CLONE_NEWNET
;
241 int path_is_temporary_fs(const char *path
) {
242 _cleanup_close_
int fd
= -1;
244 fd
= open(path
, O_RDONLY
|O_CLOEXEC
|O_NOCTTY
|O_PATH
);
248 return fd_is_temporary_fs(fd
);