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>
32 #include "mount-setup.h"
33 #include "dev-setup.h"
41 #include "path-util.h"
45 #include "smack-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|MS_STRICTATIME,
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 },
113 /* These are API file systems that might be mounted by other software,
114 * we just list them here so that we know that we should ignore them */
116 static const char ignore_paths[] =
117 /* SELinux file systems */
120 /* Legacy cgroup mount points */
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;
226 _cleanup_fclose_ FILE *f;
230 /* Mount all available cgroup controllers that are built into the kernel. */
232 f = fopen("/proc/cgroups", "re");
234 log_error("Failed to enumerate cgroup controllers: %m");
238 controllers = set_new(&string_hash_ops);
242 /* Ignore the header line */
243 (void) fgets(buf, sizeof(buf), f);
249 if (fscanf(f, "%ms %*i %*i %i", &controller, &enabled) != 2) {
254 log_error("Failed to parse /proc/cgroups.");
263 r = set_consume(controllers, controller);
265 log_error("Failed to add controller to set.");
271 _cleanup_free_ char *options = NULL, *controller = NULL, *where = NULL;
275 .flags = MS_NOSUID|MS_NOEXEC|MS_NODEV,
276 .mode = MNT_IN_CONTAINER,
280 controller = set_steal_first(controllers);
284 if (join_controllers)
285 for (k = join_controllers; *k; k++)
286 if (strv_find(*k, controller))
292 for (i = *k, j = *k; *i; i++) {
294 if (!streq(*i, controller)) {
295 _cleanup_free_ char *t;
297 t = set_remove(controllers, *i);
309 options = strv_join(*k, ",");
313 options = controller;
317 where = strappend("/sys/fs/cgroup/", options);
324 r = mount_one(&p, true);
328 if (r > 0 && k && *k) {
331 for (i = *k; *i; i++) {
332 _cleanup_free_ char *t = NULL;
334 t = strappend("/sys/fs/cgroup/", *i);
338 r = symlink(options, t);
339 if (r < 0 && errno != EEXIST) {
340 log_error("Failed to create symlink %s: %m", t);
347 /* Now that we mounted everything, let's make the tmpfs the
348 * cgroup file systems are mounted into read-only. */
349 mount("tmpfs", "/sys/fs/cgroup", "tmpfs", MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY, "mode=755");
354 #if defined(HAVE_SELINUX) || defined(HAVE_SMACK)
357 const struct stat *sb,
359 struct FTW *ftwbuf) {
361 /* No need to label /dev twice in a row... */
362 if (_unlikely_(ftwbuf->level == 0))
365 label_fix(fpath, false, false);
367 /* /run/initramfs is static data and big, no need to
368 * dynamically relabel its contents at boot... */
369 if (_unlikely_(ftwbuf->level == 1 &&
371 streq(fpath, "/run/initramfs")))
372 return FTW_SKIP_SUBTREE;
378 int mount_setup(bool loaded_policy) {
382 for (i = 0; i < ELEMENTSOF(mount_table); i ++) {
383 r = mount_one(mount_table + i, true);
389 #if defined(HAVE_SELINUX) || defined(HAVE_SMACK)
390 /* Nodes in devtmpfs and /run need to be manually updated for
391 * the appropriate labels, after mounting. The other virtual
392 * API file systems like /sys and /proc do not need that, they
393 * use the same label for all their files. */
395 usec_t before_relabel, after_relabel;
396 char timespan[FORMAT_TIMESPAN_MAX];
398 before_relabel = now(CLOCK_MONOTONIC);
400 nftw("/dev", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL);
401 nftw("/run", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL);
403 after_relabel = now(CLOCK_MONOTONIC);
405 log_info("Relabelled /dev and /run in %s.",
406 format_timespan(timespan, sizeof(timespan), after_relabel - before_relabel, 0));
410 /* Create a few default symlinks, which are normally created
411 * by udevd, but some scripts might need them before we start
415 /* Mark the root directory as shared in regards to mount
416 * propagation. The kernel defaults to "private", but we think
417 * it makes more sense to have a default of "shared" so that
418 * nspawn and the container tools work out of the box. If
419 * specific setups need other settings they can reset the
420 * propagation mode to private if needed. */
421 if (detect_container(NULL) <= 0)
422 if (mount(NULL, "/", NULL, MS_REC|MS_SHARED, NULL) < 0)
423 log_warning("Failed to set up the root directory for shared mount propagation: %m");
425 /* Create a few directories we always want around, Note that
426 * sd_booted() checks for /run/systemd/system, so this mkdir
427 * really needs to stay for good, otherwise software that
428 * copied sd-daemon.c into their sources will misdetect
430 mkdir_label("/run/systemd", 0755);
431 mkdir_label("/run/systemd/system", 0755);
432 mkdir_label("/run/systemd/inaccessible", 0000);