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8e274523 LP |
1 | /*** |
2 | This file is part of systemd. | |
3 | ||
4 | Copyright 2010 Lennart Poettering | |
5 | ||
6 | systemd is free software; you can redistribute it and/or modify it | |
5430f7f2 LP |
7 | under the terms of the GNU Lesser General Public License as published by |
8 | the Free Software Foundation; either version 2.1 of the License, or | |
8e274523 LP |
9 | (at your option) any later version. |
10 | ||
11 | systemd is distributed in the hope that it will be useful, but | |
12 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
5430f7f2 | 14 | Lesser General Public License for more details. |
8e274523 | 15 | |
5430f7f2 | 16 | You should have received a copy of the GNU Lesser General Public License |
8e274523 LP |
17 | along with systemd; If not, see <http://www.gnu.org/licenses/>. |
18 | ***/ | |
19 | ||
8e274523 | 20 | #include <errno.h> |
cf0fbc49 | 21 | #include <ftw.h> |
8e274523 | 22 | #include <stdlib.h> |
cf0fbc49 | 23 | #include <sys/mount.h> |
5c0532d1 | 24 | #include <unistd.h> |
8e274523 | 25 | |
b5efdb8a | 26 | #include "alloc-util.h" |
64824462 | 27 | #include "bus-util.h" |
4349cd7c LP |
28 | #include "cgroup-util.h" |
29 | #include "dev-setup.h" | |
30 | #include "efivars.h" | |
c4b41707 | 31 | #include "fs-util.h" |
4349cd7c | 32 | #include "label.h" |
8e274523 | 33 | #include "log.h" |
c9af1080 | 34 | #include "macro.h" |
4349cd7c | 35 | #include "missing.h" |
49e942b2 | 36 | #include "mkdir.h" |
4349cd7c LP |
37 | #include "mount-setup.h" |
38 | #include "mount-util.h" | |
9eb977db | 39 | #include "path-util.h" |
4349cd7c | 40 | #include "set.h" |
8552b176 | 41 | #include "smack-util.h" |
4349cd7c | 42 | #include "strv.h" |
ee104e11 | 43 | #include "user-util.h" |
4349cd7c LP |
44 | #include "util.h" |
45 | #include "virt.h" | |
bef2733f | 46 | |
6aa220e0 KS |
47 | typedef enum MountMode { |
48 | MNT_NONE = 0, | |
49 | MNT_FATAL = 1 << 0, | |
50 | MNT_IN_CONTAINER = 1 << 1, | |
51 | } MountMode; | |
52 | ||
ca714c0e LP |
53 | typedef struct MountPoint { |
54 | const char *what; | |
55 | const char *where; | |
56 | const char *type; | |
57 | const char *options; | |
58 | unsigned long flags; | |
6aa220e0 KS |
59 | bool (*condition_fn)(void); |
60 | MountMode mode; | |
ca714c0e LP |
61 | } MountPoint; |
62 | ||
4ef31082 | 63 | /* The first three entries we might need before SELinux is up. The |
160481f6 | 64 | * fourth (securityfs) is needed by IMA to load a custom policy. The |
7c96ab1d LP |
65 | * other ones we can delay until SELinux and IMA are loaded. When |
66 | * SMACK is enabled we need smackfs, too, so it's a fifth one. */ | |
349cc4a5 | 67 | #if HAVE_SMACK |
ffbd2c4d | 68 | #define N_EARLY_MOUNT 5 |
7c96ab1d LP |
69 | #else |
70 | #define N_EARLY_MOUNT 4 | |
71 | #endif | |
4ef31082 | 72 | |
ca714c0e | 73 | static const MountPoint mount_table[] = { |
68d4c452 LP |
74 | { "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
75 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
76 | { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
77 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
78 | { "devtmpfs", "/dev", "devtmpfs", "mode=755", MS_NOSUID|MS_STRICTATIME, | |
79 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
80 | { "securityfs", "/sys/kernel/security", "securityfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
81 | NULL, MNT_NONE }, | |
349cc4a5 | 82 | #if HAVE_SMACK |
68d4c452 LP |
83 | { "smackfs", "/sys/fs/smackfs", "smackfs", "smackfsdef=*", MS_NOSUID|MS_NOEXEC|MS_NODEV, |
84 | mac_smack_use, MNT_FATAL }, | |
85 | { "tmpfs", "/dev/shm", "tmpfs", "mode=1777,smackfsroot=*", MS_NOSUID|MS_NODEV|MS_STRICTATIME, | |
86 | mac_smack_use, MNT_FATAL }, | |
d407c940 | 87 | #endif |
68d4c452 LP |
88 | { "tmpfs", "/dev/shm", "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV|MS_STRICTATIME, |
89 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
90 | { "devpts", "/dev/pts", "devpts", "mode=620,gid=" STRINGIFY(TTY_GID), MS_NOSUID|MS_NOEXEC, | |
91 | NULL, MNT_IN_CONTAINER }, | |
349cc4a5 | 92 | #if HAVE_SMACK |
68d4c452 LP |
93 | { "tmpfs", "/run", "tmpfs", "mode=755,smackfsroot=*", MS_NOSUID|MS_NODEV|MS_STRICTATIME, |
94 | mac_smack_use, MNT_FATAL }, | |
d407c940 | 95 | #endif |
68d4c452 LP |
96 | { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID|MS_NODEV|MS_STRICTATIME, |
97 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
4095205e TH |
98 | { "cgroup", "/sys/fs/cgroup", "cgroup2", "nsdelegate", MS_NOSUID|MS_NOEXEC|MS_NODEV, |
99 | cg_is_unified_wanted, MNT_IN_CONTAINER }, | |
09961995 | 100 | { "cgroup", "/sys/fs/cgroup", "cgroup2", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
1b59cf04 | 101 | cg_is_unified_wanted, MNT_IN_CONTAINER }, |
68d4c452 | 102 | { "tmpfs", "/sys/fs/cgroup", "tmpfs", "mode=755", MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, |
efdb0237 | 103 | cg_is_legacy_wanted, MNT_FATAL|MNT_IN_CONTAINER }, |
4095205e TH |
104 | { "cgroup", "/sys/fs/cgroup/unified", "cgroup2", "nsdelegate", MS_NOSUID|MS_NOEXEC|MS_NODEV, |
105 | cg_is_hybrid_wanted, MNT_IN_CONTAINER }, | |
2977724b | 106 | { "cgroup", "/sys/fs/cgroup/unified", "cgroup2", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
a4464b95 | 107 | cg_is_hybrid_wanted, MNT_IN_CONTAINER }, |
68d4c452 | 108 | { "cgroup", "/sys/fs/cgroup/systemd", "cgroup", "none,name=systemd,xattr", MS_NOSUID|MS_NOEXEC|MS_NODEV, |
2977724b | 109 | cg_is_legacy_wanted, MNT_IN_CONTAINER }, |
68d4c452 | 110 | { "cgroup", "/sys/fs/cgroup/systemd", "cgroup", "none,name=systemd", MS_NOSUID|MS_NOEXEC|MS_NODEV, |
2977724b | 111 | cg_is_legacy_wanted, MNT_FATAL|MNT_IN_CONTAINER }, |
68d4c452 LP |
112 | { "pstore", "/sys/fs/pstore", "pstore", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
113 | NULL, MNT_NONE }, | |
349cc4a5 | 114 | #if ENABLE_EFI |
68d4c452 LP |
115 | { "efivarfs", "/sys/firmware/efi/efivars", "efivarfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
116 | is_efi_boot, MNT_NONE }, | |
c06bf414 | 117 | #endif |
63cc4c31 DM |
118 | }; |
119 | ||
949c6510 | 120 | /* These are API file systems that might be mounted by other software, |
46ff0ed7 | 121 | * we just list them here so that we know that we should ignore them */ |
949c6510 | 122 | |
eaeb18db LP |
123 | static const char ignore_paths[] = |
124 | /* SELinux file systems */ | |
125 | "/sys/fs/selinux\0" | |
eaeb18db LP |
126 | /* Container bind mounts */ |
127 | "/proc/sys\0" | |
128 | "/dev/console\0" | |
c481f78b | 129 | "/proc/kmsg\0"; |
949c6510 | 130 | |
dad08730 LP |
131 | bool mount_point_is_api(const char *path) { |
132 | unsigned i; | |
133 | ||
134 | /* Checks if this mount point is considered "API", and hence | |
135 | * should be ignored */ | |
136 | ||
ca714c0e | 137 | for (i = 0; i < ELEMENTSOF(mount_table); i ++) |
449ddb2d | 138 | if (path_equal(path, mount_table[i].where)) |
dad08730 LP |
139 | return true; |
140 | ||
57f2a956 KS |
141 | return path_startswith(path, "/sys/fs/cgroup/"); |
142 | } | |
143 | ||
144 | bool mount_point_ignore(const char *path) { | |
eaeb18db | 145 | const char *i; |
57f2a956 | 146 | |
eaeb18db LP |
147 | NULSTR_FOREACH(i, ignore_paths) |
148 | if (path_equal(path, i)) | |
949c6510 LP |
149 | return true; |
150 | ||
57f2a956 | 151 | return false; |
dad08730 LP |
152 | } |
153 | ||
4ef31082 | 154 | static int mount_one(const MountPoint *p, bool relabel) { |
8e274523 LP |
155 | int r; |
156 | ||
ca714c0e | 157 | assert(p); |
8e274523 | 158 | |
6aa220e0 KS |
159 | if (p->condition_fn && !p->condition_fn()) |
160 | return 0; | |
161 | ||
51b4af2c | 162 | /* Relabel first, just in case */ |
4ef31082 | 163 | if (relabel) |
1411b094 | 164 | (void) label_fix(p->where, true, true); |
51b4af2c | 165 | |
e1873695 | 166 | r = path_is_mount_point(p->where, NULL, AT_SYMLINK_FOLLOW); |
1411b094 LP |
167 | if (r < 0 && r != -ENOENT) { |
168 | log_full_errno((p->mode & MNT_FATAL) ? LOG_ERR : LOG_DEBUG, r, "Failed to determine whether %s is a mount point: %m", p->where); | |
169 | return (p->mode & MNT_FATAL) ? r : 0; | |
170 | } | |
8e274523 | 171 | if (r > 0) |
51b4af2c | 172 | return 0; |
8e274523 | 173 | |
c481f78b | 174 | /* Skip securityfs in a container */ |
75f86906 | 175 | if (!(p->mode & MNT_IN_CONTAINER) && detect_container() > 0) |
c481f78b LP |
176 | return 0; |
177 | ||
a04f58d6 LP |
178 | /* The access mode here doesn't really matter too much, since |
179 | * the mounted file system will take precedence anyway. */ | |
c4bfd169 | 180 | if (relabel) |
1411b094 | 181 | (void) mkdir_p_label(p->where, 0755); |
c4bfd169 | 182 | else |
1411b094 | 183 | (void) mkdir_p(p->where, 0755); |
a04f58d6 | 184 | |
8e274523 | 185 | log_debug("Mounting %s to %s of type %s with options %s.", |
ca714c0e LP |
186 | p->what, |
187 | p->where, | |
188 | p->type, | |
189 | strna(p->options)); | |
190 | ||
191 | if (mount(p->what, | |
192 | p->where, | |
193 | p->type, | |
194 | p->flags, | |
195 | p->options) < 0) { | |
1411b094 | 196 | log_full_errno((p->mode & MNT_FATAL) ? LOG_ERR : LOG_DEBUG, errno, "Failed to mount %s at %s: %m", p->type, p->where); |
6aa220e0 | 197 | return (p->mode & MNT_FATAL) ? -errno : 0; |
8e274523 LP |
198 | } |
199 | ||
51b4af2c | 200 | /* Relabel again, since we now mounted something fresh here */ |
4ef31082 | 201 | if (relabel) |
1411b094 | 202 | (void) label_fix(p->where, false, false); |
5275d3c1 | 203 | |
0c85a4f3 | 204 | return 1; |
8e274523 LP |
205 | } |
206 | ||
400fac06 | 207 | static int mount_points_setup(unsigned n, bool loaded_policy) { |
4ef31082 LP |
208 | unsigned i; |
209 | int r = 0; | |
210 | ||
400fac06 | 211 | for (i = 0; i < n; i ++) { |
4ef31082 LP |
212 | int j; |
213 | ||
400fac06 | 214 | j = mount_one(mount_table + i, loaded_policy); |
7ff307bc | 215 | if (j != 0 && r >= 0) |
4ef31082 LP |
216 | r = j; |
217 | } | |
218 | ||
219 | return r; | |
220 | } | |
221 | ||
400fac06 AK |
222 | int mount_setup_early(void) { |
223 | assert_cc(N_EARLY_MOUNT <= ELEMENTSOF(mount_table)); | |
224 | ||
225 | /* Do a minimal mount of /proc and friends to enable the most | |
226 | * basic stuff, such as SELinux */ | |
227 | return mount_points_setup(N_EARLY_MOUNT, false); | |
228 | } | |
229 | ||
0c85a4f3 | 230 | int mount_cgroup_controllers(char ***join_controllers) { |
a6b26d90 | 231 | _cleanup_set_free_free_ Set *controllers = NULL; |
a641dcd9 | 232 | int r; |
2076ca54 | 233 | |
efdb0237 LP |
234 | if (!cg_is_legacy_wanted()) |
235 | return 0; | |
236 | ||
670802d4 | 237 | /* Mount all available cgroup controllers that are built into the kernel. */ |
2076ca54 | 238 | |
d5099efc | 239 | controllers = set_new(&string_hash_ops); |
a6b26d90 ZJS |
240 | if (!controllers) |
241 | return log_oom(); | |
0c85a4f3 | 242 | |
b12afc8c LP |
243 | r = cg_kernel_controllers(controllers); |
244 | if (r < 0) | |
245 | return log_error_errno(r, "Failed to enumerate cgroup controllers: %m"); | |
0c85a4f3 LP |
246 | |
247 | for (;;) { | |
a641dcd9 | 248 | _cleanup_free_ char *options = NULL, *controller = NULL, *where = NULL; |
a6b26d90 ZJS |
249 | MountPoint p = { |
250 | .what = "cgroup", | |
251 | .type = "cgroup", | |
252 | .flags = MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
253 | .mode = MNT_IN_CONTAINER, | |
254 | }; | |
0c85a4f3 LP |
255 | char ***k = NULL; |
256 | ||
257 | controller = set_steal_first(controllers); | |
258 | if (!controller) | |
259 | break; | |
260 | ||
261 | if (join_controllers) | |
262 | for (k = join_controllers; *k; k++) | |
263 | if (strv_find(*k, controller)) | |
264 | break; | |
265 | ||
266 | if (k && *k) { | |
267 | char **i, **j; | |
268 | ||
269 | for (i = *k, j = *k; *i; i++) { | |
270 | ||
271 | if (!streq(*i, controller)) { | |
a641dcd9 | 272 | _cleanup_free_ char *t; |
0c85a4f3 LP |
273 | |
274 | t = set_remove(controllers, *i); | |
275 | if (!t) { | |
276 | free(*i); | |
277 | continue; | |
278 | } | |
0c85a4f3 LP |
279 | } |
280 | ||
281 | *(j++) = *i; | |
282 | } | |
283 | ||
284 | *j = NULL; | |
285 | ||
286 | options = strv_join(*k, ","); | |
a6b26d90 ZJS |
287 | if (!options) |
288 | return log_oom(); | |
0c85a4f3 LP |
289 | } else { |
290 | options = controller; | |
291 | controller = NULL; | |
292 | } | |
293 | ||
a641dcd9 LP |
294 | where = strappend("/sys/fs/cgroup/", options); |
295 | if (!where) | |
296 | return log_oom(); | |
297 | ||
298 | p.where = where; | |
0c85a4f3 | 299 | p.options = options; |
2076ca54 | 300 | |
4ef31082 | 301 | r = mount_one(&p, true); |
a6b26d90 ZJS |
302 | if (r < 0) |
303 | return r; | |
0c85a4f3 LP |
304 | |
305 | if (r > 0 && k && *k) { | |
306 | char **i; | |
307 | ||
308 | for (i = *k; *i; i++) { | |
a641dcd9 LP |
309 | _cleanup_free_ char *t = NULL; |
310 | ||
311 | t = strappend("/sys/fs/cgroup/", *i); | |
312 | if (!t) | |
313 | return log_oom(); | |
0c85a4f3 LP |
314 | |
315 | r = symlink(options, t); | |
ea2b93a8 | 316 | if (r >= 0) { |
f8c1a81c | 317 | #ifdef SMACK_RUN_LABEL |
ea2b93a8 PO |
318 | _cleanup_free_ char *src; |
319 | src = strappend("/sys/fs/cgroup/", options); | |
320 | if (!src) | |
321 | return log_oom(); | |
322 | r = mac_smack_copy(t, src); | |
323 | if (r < 0 && r != -EOPNOTSUPP) | |
324 | return log_error_errno(r, "Failed to copy smack label from %s to %s: %m", src, t); | |
f8c1a81c | 325 | #endif |
ea2b93a8 PO |
326 | } else if (errno != EEXIST) |
327 | return log_error_errno(errno, "Failed to create symlink %s: %m", t); | |
0c85a4f3 LP |
328 | } |
329 | } | |
2076ca54 LP |
330 | } |
331 | ||
679142ce LP |
332 | /* Now that we mounted everything, let's make the tmpfs the |
333 | * cgroup file systems are mounted into read-only. */ | |
b12afc8c | 334 | (void) mount("tmpfs", "/sys/fs/cgroup", "tmpfs", MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY, "mode=755"); |
679142ce | 335 | |
a6b26d90 | 336 | return 0; |
2076ca54 LP |
337 | } |
338 | ||
349cc4a5 | 339 | #if HAVE_SELINUX || HAVE_SMACK |
1829dc9d LP |
340 | static int nftw_cb( |
341 | const char *fpath, | |
342 | const struct stat *sb, | |
343 | int tflag, | |
344 | struct FTW *ftwbuf) { | |
345 | ||
9fe117ea | 346 | /* No need to label /dev twice in a row... */ |
edb49778 LP |
347 | if (_unlikely_(ftwbuf->level == 0)) |
348 | return FTW_CONTINUE; | |
349 | ||
c9bc0764 | 350 | label_fix(fpath, false, false); |
af65c248 | 351 | |
edb49778 | 352 | /* /run/initramfs is static data and big, no need to |
af65c248 | 353 | * dynamically relabel its contents at boot... */ |
edb49778 LP |
354 | if (_unlikely_(ftwbuf->level == 1 && |
355 | tflag == FTW_D && | |
356 | streq(fpath, "/run/initramfs"))) | |
357 | return FTW_SKIP_SUBTREE; | |
9fe117ea | 358 | |
edb49778 | 359 | return FTW_CONTINUE; |
1829dc9d | 360 | }; |
0fff82e5 | 361 | #endif |
1829dc9d | 362 | |
0b3325e7 | 363 | int mount_setup(bool loaded_policy) { |
68d4c452 | 364 | int r = 0; |
8e274523 | 365 | |
400fac06 | 366 | r = mount_points_setup(ELEMENTSOF(mount_table), loaded_policy); |
68d4c452 LP |
367 | if (r < 0) |
368 | return r; | |
369 | ||
349cc4a5 | 370 | #if HAVE_SELINUX || HAVE_SMACK |
f1d19aa4 LP |
371 | /* Nodes in devtmpfs and /run need to be manually updated for |
372 | * the appropriate labels, after mounting. The other virtual | |
373 | * API file systems like /sys and /proc do not need that, they | |
374 | * use the same label for all their files. */ | |
0b3325e7 LP |
375 | if (loaded_policy) { |
376 | usec_t before_relabel, after_relabel; | |
377 | char timespan[FORMAT_TIMESPAN_MAX]; | |
378 | ||
379 | before_relabel = now(CLOCK_MONOTONIC); | |
380 | ||
edb49778 | 381 | nftw("/dev", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL); |
cacf980e | 382 | nftw("/dev/shm", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL); |
edb49778 | 383 | nftw("/run", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL); |
0b3325e7 LP |
384 | |
385 | after_relabel = now(CLOCK_MONOTONIC); | |
386 | ||
387 | log_info("Relabelled /dev and /run in %s.", | |
2fa4092c | 388 | format_timespan(timespan, sizeof(timespan), after_relabel - before_relabel, 0)); |
3bbecb2f | 389 | } |
0fff82e5 | 390 | #endif |
1829dc9d | 391 | |
5c0532d1 | 392 | /* Create a few default symlinks, which are normally created |
f1d19aa4 | 393 | * by udevd, but some scripts might need them before we start |
5c0532d1 | 394 | * udevd. */ |
03cfe0d5 | 395 | dev_setup(NULL, UID_INVALID, GID_INVALID); |
5c0532d1 | 396 | |
dee22f39 LP |
397 | /* Mark the root directory as shared in regards to mount propagation. The kernel defaults to "private", but we |
398 | * think it makes more sense to have a default of "shared" so that nspawn and the container tools work out of | |
399 | * the box. If specific setups need other settings they can reset the propagation mode to private if | |
400 | * needed. Note that we set this only when we are invoked directly by the kernel. If we are invoked by a | |
401 | * container manager we assume the container manager knows what it is doing (for example, because it set up | |
402 | * some directories with different propagation modes). */ | |
75f86906 | 403 | if (detect_container() <= 0) |
c481f78b | 404 | if (mount(NULL, "/", NULL, MS_REC|MS_SHARED, NULL) < 0) |
56f64d95 | 405 | log_warning_errno(errno, "Failed to set up the root directory for shared mount propagation: %m"); |
b3ac5f8c | 406 | |
dee22f39 LP |
407 | /* Create a few directories we always want around, Note that sd_booted() checks for /run/systemd/system, so |
408 | * this mkdir really needs to stay for good, otherwise software that copied sd-daemon.c into their sources will | |
409 | * misdetect systemd. */ | |
c4b41707 AP |
410 | (void) mkdir_label("/run/systemd", 0755); |
411 | (void) mkdir_label("/run/systemd/system", 0755); | |
dee22f39 | 412 | |
c4b41707 | 413 | /* Set up inaccessible items */ |
dee22f39 | 414 | (void) mkdir_label("/run/systemd/inaccessible", 0000); |
c4b41707 AP |
415 | (void) mknod("/run/systemd/inaccessible/reg", S_IFREG | 0000, 0); |
416 | (void) mkdir_label("/run/systemd/inaccessible/dir", 0000); | |
417 | (void) mknod("/run/systemd/inaccessible/chr", S_IFCHR | 0000, makedev(0, 0)); | |
418 | (void) mknod("/run/systemd/inaccessible/blk", S_IFBLK | 0000, makedev(0, 0)); | |
419 | (void) mkfifo("/run/systemd/inaccessible/fifo", 0000); | |
420 | (void) mknod("/run/systemd/inaccessible/sock", S_IFSOCK | 0000, 0); | |
b925e726 | 421 | |
0c85a4f3 | 422 | return 0; |
8e274523 | 423 | } |