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 /* Legacy kernel file system */
125 /* Container bind mounts */
130 bool mount_point_is_api(const char *path) {
133 /* Checks if this mount point is considered "API", and hence
134 * should be ignored */
136 for (i = 0; i < ELEMENTSOF(mount_table); i ++)
137 if (path_equal(path, mount_table[i].where))
140 return path_startswith(path, "/sys/fs/cgroup/");
143 bool mount_point_ignore(const char *path) {
146 NULSTR_FOREACH(i, ignore_paths)
147 if (path_equal(path, i))
153 static int mount_one(const MountPoint *p, bool relabel) {
158 if (p->condition_fn && !p->condition_fn())
161 /* Relabel first, just in case */
163 label_fix(p->where, true, true);
165 r = path_is_mount_point(p->where, true);
172 /* Skip securityfs in a container */
173 if (!(p->mode & MNT_IN_CONTAINER) && detect_container(NULL) > 0)
176 /* The access mode here doesn't really matter too much, since
177 * the mounted file system will take precedence anyway. */
179 mkdir_p_label(p->where, 0755);
181 mkdir_p(p->where, 0755);
183 log_debug("Mounting %s to %s of type %s with options %s.",
194 log_full((p->mode & MNT_FATAL) ? LOG_ERR : LOG_DEBUG, "Failed to mount %s at %s: %m", p->type, p->where);
195 return (p->mode & MNT_FATAL) ? -errno : 0;
198 /* Relabel again, since we now mounted something fresh here */
200 label_fix(p->where, false, false);
205 int mount_setup_early(void) {
209 assert_cc(N_EARLY_MOUNT <= ELEMENTSOF(mount_table));
211 /* Do a minimal mount of /proc and friends to enable the most
212 * basic stuff, such as SELinux */
213 for (i = 0; i < N_EARLY_MOUNT; i ++) {
216 j = mount_one(mount_table + i, false);
224 int mount_cgroup_controllers(char ***join_controllers) {
225 _cleanup_set_free_free_ Set *controllers = NULL;
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);
307 if (r < 0 && errno != EEXIST)
308 return log_error_errno(errno, "Failed to create symlink %s: %m", t);
313 /* Now that we mounted everything, let's make the tmpfs the
314 * cgroup file systems are mounted into read-only. */
315 (void) mount("tmpfs", "/sys/fs/cgroup", "tmpfs", MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY, "mode=755");
320 #if defined(HAVE_SELINUX) || defined(HAVE_SMACK)
323 const struct stat *sb,
325 struct FTW *ftwbuf) {
327 /* No need to label /dev twice in a row... */
328 if (_unlikely_(ftwbuf->level == 0))
331 label_fix(fpath, false, false);
333 /* /run/initramfs is static data and big, no need to
334 * dynamically relabel its contents at boot... */
335 if (_unlikely_(ftwbuf->level == 1 &&
337 streq(fpath, "/run/initramfs")))
338 return FTW_SKIP_SUBTREE;
344 int mount_setup(bool loaded_policy) {
348 for (i = 0; i < ELEMENTSOF(mount_table); i ++) {
351 j = mount_one(mount_table + i, loaded_policy);
359 #if defined(HAVE_SELINUX) || defined(HAVE_SMACK)
360 /* Nodes in devtmpfs and /run need to be manually updated for
361 * the appropriate labels, after mounting. The other virtual
362 * API file systems like /sys and /proc do not need that, they
363 * use the same label for all their files. */
365 usec_t before_relabel, after_relabel;
366 char timespan[FORMAT_TIMESPAN_MAX];
368 before_relabel = now(CLOCK_MONOTONIC);
370 nftw("/dev", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL);
371 nftw("/run", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL);
373 after_relabel = now(CLOCK_MONOTONIC);
375 log_info("Relabelled /dev and /run in %s.",
376 format_timespan(timespan, sizeof(timespan), after_relabel - before_relabel, 0));
380 /* Create a few default symlinks, which are normally created
381 * by udevd, but some scripts might need them before we start
385 /* Mark the root directory as shared in regards to mount
386 * propagation. The kernel defaults to "private", but we think
387 * it makes more sense to have a default of "shared" so that
388 * nspawn and the container tools work out of the box. If
389 * specific setups need other settings they can reset the
390 * propagation mode to private if needed. */
391 if (detect_container(NULL) <= 0)
392 if (mount(NULL, "/", NULL, MS_REC|MS_SHARED, NULL) < 0)
393 log_warning_errno(errno, "Failed to set up the root directory for shared mount propagation: %m");
395 /* Create a few directories we always want around, Note that
396 * sd_booted() checks for /run/systemd/system, so this mkdir
397 * really needs to stay for good, otherwise software that
398 * copied sd-daemon.c into their sources will misdetect
400 mkdir_label("/run/systemd", 0755);
401 mkdir_label("/run/systemd/system", 0755);
402 mkdir_label("/run/systemd/inaccessible", 0000);