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/>.
22 #include <sys/mount.h>
31 #include "mount-setup.h"
32 #include "dev-setup.h"
40 #include "path-util.h"
44 #include "smack-util.h"
46 #include "cgroup-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 { "tmpfs", "/sys/fs/cgroup", "tmpfs", "mode=755", MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME,
100 NULL, MNT_FATAL|MNT_IN_CONTAINER },
101 { "cgroup", "/sys/fs/cgroup/systemd", "cgroup", "none,name=systemd,xattr", MS_NOSUID|MS_NOEXEC|MS_NODEV,
102 NULL, MNT_IN_CONTAINER },
103 { "cgroup", "/sys/fs/cgroup/systemd", "cgroup", "none,name=systemd", MS_NOSUID|MS_NOEXEC|MS_NODEV,
104 NULL, MNT_FATAL|MNT_IN_CONTAINER },
105 { "pstore", "/sys/fs/pstore", "pstore", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV,
108 { "efivarfs", "/sys/firmware/efi/efivars", "efivarfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV,
109 is_efi_boot, MNT_NONE },
112 { "kdbusfs", "/sys/fs/kdbus", "kdbusfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV,
113 NULL, 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, true);
170 /* Skip securityfs in a container */
171 if (!(p->mode & MNT_IN_CONTAINER) && detect_container(NULL) > 0)
174 /* The access mode here doesn't really matter too much, since
175 * the mounted file system will take precedence anyway. */
177 mkdir_p_label(p->where, 0755);
179 mkdir_p(p->where, 0755);
181 log_debug("Mounting %s to %s of type %s with options %s.",
192 log_full((p->mode & MNT_FATAL) ? LOG_ERR : LOG_DEBUG, "Failed to mount %s at %s: %m", p->type, p->where);
193 return (p->mode & MNT_FATAL) ? -errno : 0;
196 /* Relabel again, since we now mounted something fresh here */
198 label_fix(p->where, false, false);
203 int mount_setup_early(void) {
207 assert_cc(N_EARLY_MOUNT <= ELEMENTSOF(mount_table));
209 /* Do a minimal mount of /proc and friends to enable the most
210 * basic stuff, such as SELinux */
211 for (i = 0; i < N_EARLY_MOUNT; i ++) {
214 j = mount_one(mount_table + i, false);
222 int mount_cgroup_controllers(char ***join_controllers) {
223 _cleanup_set_free_free_ Set *controllers = NULL;
226 /* Mount all available cgroup controllers that are built into the kernel. */
228 controllers = set_new(&string_hash_ops);
232 r = cg_kernel_controllers(controllers);
234 return log_error_errno(r, "Failed to enumerate cgroup controllers: %m");
237 _cleanup_free_ char *options = NULL, *controller = NULL, *where = NULL;
241 .flags = MS_NOSUID|MS_NOEXEC|MS_NODEV,
242 .mode = MNT_IN_CONTAINER,
246 controller = set_steal_first(controllers);
250 if (join_controllers)
251 for (k = join_controllers; *k; k++)
252 if (strv_find(*k, controller))
258 for (i = *k, j = *k; *i; i++) {
260 if (!streq(*i, controller)) {
261 _cleanup_free_ char *t;
263 t = set_remove(controllers, *i);
275 options = strv_join(*k, ",");
279 options = controller;
283 where = strappend("/sys/fs/cgroup/", options);
290 r = mount_one(&p, true);
294 if (r > 0 && k && *k) {
297 for (i = *k; *i; i++) {
298 _cleanup_free_ char *t = NULL;
300 t = strappend("/sys/fs/cgroup/", *i);
304 r = symlink(options, t);
305 if (r < 0 && errno != EEXIST)
306 return log_error_errno(errno, "Failed to create symlink %s: %m", t);
311 /* Now that we mounted everything, let's make the tmpfs the
312 * cgroup file systems are mounted into read-only. */
313 (void) mount("tmpfs", "/sys/fs/cgroup", "tmpfs", MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY, "mode=755");
318 #if defined(HAVE_SELINUX) || defined(HAVE_SMACK)
321 const struct stat *sb,
323 struct FTW *ftwbuf) {
325 /* No need to label /dev twice in a row... */
326 if (_unlikely_(ftwbuf->level == 0))
329 label_fix(fpath, false, false);
331 /* /run/initramfs is static data and big, no need to
332 * dynamically relabel its contents at boot... */
333 if (_unlikely_(ftwbuf->level == 1 &&
335 streq(fpath, "/run/initramfs")))
336 return FTW_SKIP_SUBTREE;
342 int mount_setup(bool loaded_policy) {
346 for (i = 0; i < ELEMENTSOF(mount_table); i ++) {
349 j = mount_one(mount_table + i, loaded_policy);
357 #if defined(HAVE_SELINUX) || defined(HAVE_SMACK)
358 /* Nodes in devtmpfs and /run need to be manually updated for
359 * the appropriate labels, after mounting. The other virtual
360 * API file systems like /sys and /proc do not need that, they
361 * use the same label for all their files. */
363 usec_t before_relabel, after_relabel;
364 char timespan[FORMAT_TIMESPAN_MAX];
366 before_relabel = now(CLOCK_MONOTONIC);
368 nftw("/dev", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL);
369 nftw("/run", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL);
371 after_relabel = now(CLOCK_MONOTONIC);
373 log_info("Relabelled /dev and /run in %s.",
374 format_timespan(timespan, sizeof(timespan), after_relabel - before_relabel, 0));
378 /* Create a few default symlinks, which are normally created
379 * by udevd, but some scripts might need them before we start
383 /* Mark the root directory as shared in regards to mount
384 * propagation. The kernel defaults to "private", but we think
385 * it makes more sense to have a default of "shared" so that
386 * nspawn and the container tools work out of the box. If
387 * specific setups need other settings they can reset the
388 * propagation mode to private if needed. */
389 if (detect_container(NULL) <= 0)
390 if (mount(NULL, "/", NULL, MS_REC|MS_SHARED, NULL) < 0)
391 log_warning_errno(errno, "Failed to set up the root directory for shared mount propagation: %m");
393 /* Create a few directories we always want around, Note that
394 * sd_booted() checks for /run/systemd/system, so this mkdir
395 * really needs to stay for good, otherwise software that
396 * copied sd-daemon.c into their sources will misdetect
398 mkdir_label("/run/systemd", 0755);
399 mkdir_label("/run/systemd/system", 0755);
400 mkdir_label("/run/systemd/inaccessible", 0000);