1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2010 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 2.1 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
25 #include <sys/mount.h>
28 #include "alloc-util.h"
30 #include "cgroup-util.h"
31 #include "dev-setup.h"
38 #include "mount-setup.h"
39 #include "mount-util.h"
40 #include "path-util.h"
42 #include "smack-util.h"
44 #include "user-util.h"
48 typedef enum MountMode
{
51 MNT_IN_CONTAINER
= 1 << 1,
54 typedef struct MountPoint
{
60 bool (*condition_fn
)(void);
64 /* The first three entries we might need before SELinux is up. The
65 * fourth (securityfs) is needed by IMA to load a custom policy. The
66 * other ones we can delay until SELinux and IMA are loaded. When
67 * SMACK is enabled we need smackfs, too, so it's a fifth one. */
69 #define N_EARLY_MOUNT 5
71 #define N_EARLY_MOUNT 4
74 static const MountPoint mount_table
[] = {
75 { "sysfs", "/sys", "sysfs", NULL
, MS_NOSUID
|MS_NOEXEC
|MS_NODEV
,
76 NULL
, MNT_FATAL
|MNT_IN_CONTAINER
},
77 { "proc", "/proc", "proc", NULL
, MS_NOSUID
|MS_NOEXEC
|MS_NODEV
,
78 NULL
, MNT_FATAL
|MNT_IN_CONTAINER
},
79 { "devtmpfs", "/dev", "devtmpfs", "mode=755", MS_NOSUID
|MS_STRICTATIME
,
80 NULL
, MNT_FATAL
|MNT_IN_CONTAINER
},
81 { "securityfs", "/sys/kernel/security", "securityfs", NULL
, MS_NOSUID
|MS_NOEXEC
|MS_NODEV
,
84 { "smackfs", "/sys/fs/smackfs", "smackfs", "smackfsdef=*", MS_NOSUID
|MS_NOEXEC
|MS_NODEV
,
85 mac_smack_use
, MNT_FATAL
},
86 { "tmpfs", "/dev/shm", "tmpfs", "mode=1777,smackfsroot=*", MS_NOSUID
|MS_NODEV
|MS_STRICTATIME
,
87 mac_smack_use
, MNT_FATAL
},
89 { "tmpfs", "/dev/shm", "tmpfs", "mode=1777", MS_NOSUID
|MS_NODEV
|MS_STRICTATIME
,
90 NULL
, MNT_FATAL
|MNT_IN_CONTAINER
},
91 { "devpts", "/dev/pts", "devpts", "mode=620,gid=" STRINGIFY(TTY_GID
), MS_NOSUID
|MS_NOEXEC
,
92 NULL
, MNT_IN_CONTAINER
},
94 { "tmpfs", "/run", "tmpfs", "mode=755,smackfsroot=*", MS_NOSUID
|MS_NODEV
|MS_STRICTATIME
,
95 mac_smack_use
, MNT_FATAL
},
97 { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID
|MS_NODEV
|MS_STRICTATIME
,
98 NULL
, MNT_FATAL
|MNT_IN_CONTAINER
},
99 { "cgroup", "/sys/fs/cgroup", "cgroup", "__DEVEL__sane_behavior", MS_NOSUID
|MS_NOEXEC
|MS_NODEV
,
100 cg_is_unified_wanted
, MNT_FATAL
|MNT_IN_CONTAINER
},
101 { "tmpfs", "/sys/fs/cgroup", "tmpfs", "mode=755", MS_NOSUID
|MS_NOEXEC
|MS_NODEV
|MS_STRICTATIME
,
102 cg_is_legacy_wanted
, MNT_FATAL
|MNT_IN_CONTAINER
},
103 { "cgroup", "/sys/fs/cgroup/systemd", "cgroup", "none,name=systemd,xattr", MS_NOSUID
|MS_NOEXEC
|MS_NODEV
,
104 cg_is_legacy_wanted
, MNT_IN_CONTAINER
},
105 { "cgroup", "/sys/fs/cgroup/systemd", "cgroup", "none,name=systemd", MS_NOSUID
|MS_NOEXEC
|MS_NODEV
,
106 cg_is_legacy_wanted
, MNT_FATAL
|MNT_IN_CONTAINER
},
107 { "pstore", "/sys/fs/pstore", "pstore", NULL
, MS_NOSUID
|MS_NOEXEC
|MS_NODEV
,
110 { "efivarfs", "/sys/firmware/efi/efivars", "efivarfs", NULL
, MS_NOSUID
|MS_NOEXEC
|MS_NODEV
,
111 is_efi_boot
, MNT_NONE
},
113 { "kdbusfs", "/sys/fs/kdbus", "kdbusfs", NULL
, MS_NOSUID
|MS_NOEXEC
|MS_NODEV
,
114 is_kdbus_wanted
, MNT_IN_CONTAINER
},
117 /* These are API file systems that might be mounted by other software,
118 * we just list them here so that we know that we should ignore them */
120 static const char ignore_paths
[] =
121 /* SELinux file systems */
123 /* Container bind mounts */
128 bool mount_point_is_api(const char *path
) {
131 /* Checks if this mount point is considered "API", and hence
132 * should be ignored */
134 for (i
= 0; i
< ELEMENTSOF(mount_table
); i
++)
135 if (path_equal(path
, mount_table
[i
].where
))
138 return path_startswith(path
, "/sys/fs/cgroup/");
141 bool mount_point_ignore(const char *path
) {
144 NULSTR_FOREACH(i
, ignore_paths
)
145 if (path_equal(path
, i
))
151 static int mount_one(const MountPoint
*p
, bool relabel
) {
156 if (p
->condition_fn
&& !p
->condition_fn())
159 /* Relabel first, just in case */
161 label_fix(p
->where
, true, true);
163 r
= path_is_mount_point(p
->where
, AT_SYMLINK_FOLLOW
);
164 if (r
< 0 && r
!= -ENOENT
)
169 /* Skip securityfs in a container */
170 if (!(p
->mode
& MNT_IN_CONTAINER
) && detect_container() > 0)
173 /* The access mode here doesn't really matter too much, since
174 * the mounted file system will take precedence anyway. */
176 mkdir_p_label(p
->where
, 0755);
178 mkdir_p(p
->where
, 0755);
180 log_debug("Mounting %s to %s of type %s with options %s.",
191 log_full((p
->mode
& MNT_FATAL
) ? LOG_ERR
: LOG_DEBUG
, "Failed to mount %s at %s: %m", p
->type
, p
->where
);
192 return (p
->mode
& MNT_FATAL
) ? -errno
: 0;
195 /* Relabel again, since we now mounted something fresh here */
197 label_fix(p
->where
, false, false);
202 int mount_setup_early(void) {
206 assert_cc(N_EARLY_MOUNT
<= ELEMENTSOF(mount_table
));
208 /* Do a minimal mount of /proc and friends to enable the most
209 * basic stuff, such as SELinux */
210 for (i
= 0; i
< N_EARLY_MOUNT
; i
++) {
213 j
= mount_one(mount_table
+ i
, false);
214 if (j
!= 0 && r
>= 0)
221 int mount_cgroup_controllers(char ***join_controllers
) {
222 _cleanup_set_free_free_ Set
*controllers
= NULL
;
225 if (!cg_is_legacy_wanted())
228 /* Mount all available cgroup controllers that are built into the kernel. */
230 controllers
= set_new(&string_hash_ops
);
234 r
= cg_kernel_controllers(controllers
);
236 return log_error_errno(r
, "Failed to enumerate cgroup controllers: %m");
239 _cleanup_free_
char *options
= NULL
, *controller
= NULL
, *where
= NULL
;
243 .flags
= MS_NOSUID
|MS_NOEXEC
|MS_NODEV
,
244 .mode
= MNT_IN_CONTAINER
,
248 controller
= set_steal_first(controllers
);
252 if (join_controllers
)
253 for (k
= join_controllers
; *k
; k
++)
254 if (strv_find(*k
, controller
))
260 for (i
= *k
, j
= *k
; *i
; i
++) {
262 if (!streq(*i
, controller
)) {
263 _cleanup_free_
char *t
;
265 t
= set_remove(controllers
, *i
);
277 options
= strv_join(*k
, ",");
281 options
= controller
;
285 where
= strappend("/sys/fs/cgroup/", options
);
292 r
= mount_one(&p
, true);
296 if (r
> 0 && k
&& *k
) {
299 for (i
= *k
; *i
; i
++) {
300 _cleanup_free_
char *t
= NULL
;
302 t
= strappend("/sys/fs/cgroup/", *i
);
306 r
= symlink(options
, t
);
308 #ifdef SMACK_RUN_LABEL
309 _cleanup_free_
char *src
;
310 src
= strappend("/sys/fs/cgroup/", options
);
313 r
= mac_smack_copy(t
, src
);
314 if (r
< 0 && r
!= -EOPNOTSUPP
)
315 return log_error_errno(r
, "Failed to copy smack label from %s to %s: %m", src
, t
);
317 } else if (errno
!= EEXIST
)
318 return log_error_errno(errno
, "Failed to create symlink %s: %m", t
);
323 /* Now that we mounted everything, let's make the tmpfs the
324 * cgroup file systems are mounted into read-only. */
325 (void) mount("tmpfs", "/sys/fs/cgroup", "tmpfs", MS_REMOUNT
|MS_NOSUID
|MS_NOEXEC
|MS_NODEV
|MS_STRICTATIME
|MS_RDONLY
, "mode=755");
330 #if defined(HAVE_SELINUX) || defined(HAVE_SMACK)
333 const struct stat
*sb
,
335 struct FTW
*ftwbuf
) {
337 /* No need to label /dev twice in a row... */
338 if (_unlikely_(ftwbuf
->level
== 0))
341 label_fix(fpath
, false, false);
343 /* /run/initramfs is static data and big, no need to
344 * dynamically relabel its contents at boot... */
345 if (_unlikely_(ftwbuf
->level
== 1 &&
347 streq(fpath
, "/run/initramfs")))
348 return FTW_SKIP_SUBTREE
;
354 int mount_setup(bool loaded_policy
) {
358 for (i
= 0; i
< ELEMENTSOF(mount_table
); i
++) {
361 j
= mount_one(mount_table
+ i
, loaded_policy
);
362 if (j
!= 0 && r
>= 0)
369 #if defined(HAVE_SELINUX) || defined(HAVE_SMACK)
370 /* Nodes in devtmpfs and /run need to be manually updated for
371 * the appropriate labels, after mounting. The other virtual
372 * API file systems like /sys and /proc do not need that, they
373 * use the same label for all their files. */
375 usec_t before_relabel
, after_relabel
;
376 char timespan
[FORMAT_TIMESPAN_MAX
];
378 before_relabel
= now(CLOCK_MONOTONIC
);
380 nftw("/dev", nftw_cb
, 64, FTW_MOUNT
|FTW_PHYS
|FTW_ACTIONRETVAL
);
381 nftw("/run", nftw_cb
, 64, FTW_MOUNT
|FTW_PHYS
|FTW_ACTIONRETVAL
);
383 after_relabel
= now(CLOCK_MONOTONIC
);
385 log_info("Relabelled /dev and /run in %s.",
386 format_timespan(timespan
, sizeof(timespan
), after_relabel
- before_relabel
, 0));
390 /* Create a few default symlinks, which are normally created
391 * by udevd, but some scripts might need them before we start
393 dev_setup(NULL
, UID_INVALID
, GID_INVALID
);
395 /* Mark the root directory as shared in regards to mount
396 * propagation. The kernel defaults to "private", but we think
397 * it makes more sense to have a default of "shared" so that
398 * nspawn and the container tools work out of the box. If
399 * specific setups need other settings they can reset the
400 * propagation mode to private if needed. */
401 if (detect_container() <= 0)
402 if (mount(NULL
, "/", NULL
, MS_REC
|MS_SHARED
, NULL
) < 0)
403 log_warning_errno(errno
, "Failed to set up the root directory for shared mount propagation: %m");
405 /* Create a few directories we always want around, Note that
406 * sd_booted() checks for /run/systemd/system, so this mkdir
407 * really needs to stay for good, otherwise software that
408 * copied sd-daemon.c into their sources will misdetect
410 mkdir_label("/run/systemd", 0755);
411 mkdir_label("/run/systemd/system", 0755);
412 mkdir_label("/run/systemd/inaccessible", 0000);