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d6c9574f | 1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
8e274523 LP |
2 | |
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2010 Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
5430f7f2 LP |
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 | |
8e274523 LP |
11 | (at your option) any later version. |
12 | ||
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 | |
5430f7f2 | 16 | Lesser General Public License for more details. |
8e274523 | 17 | |
5430f7f2 | 18 | You should have received a copy of the GNU Lesser General Public License |
8e274523 LP |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. |
20 | ***/ | |
21 | ||
22 | #include <sys/mount.h> | |
23 | #include <errno.h> | |
8e274523 | 24 | #include <stdlib.h> |
5c0532d1 | 25 | #include <unistd.h> |
1829dc9d | 26 | #include <ftw.h> |
8e274523 LP |
27 | |
28 | #include "mount-setup.h" | |
5ba2dc25 | 29 | #include "dev-setup.h" |
64824462 | 30 | #include "bus-util.h" |
8e274523 | 31 | #include "log.h" |
c9af1080 LP |
32 | #include "macro.h" |
33 | #include "util.h" | |
5275d3c1 | 34 | #include "label.h" |
0c85a4f3 LP |
35 | #include "set.h" |
36 | #include "strv.h" | |
49e942b2 | 37 | #include "mkdir.h" |
9eb977db | 38 | #include "path-util.h" |
48ac500b | 39 | #include "missing.h" |
c481f78b | 40 | #include "virt.h" |
34e5a31e | 41 | #include "efivars.h" |
8552b176 | 42 | #include "smack-util.h" |
b12afc8c | 43 | #include "cgroup-util.h" |
bef2733f | 44 | |
6aa220e0 KS |
45 | typedef enum MountMode { |
46 | MNT_NONE = 0, | |
47 | MNT_FATAL = 1 << 0, | |
48 | MNT_IN_CONTAINER = 1 << 1, | |
49 | } MountMode; | |
50 | ||
ca714c0e LP |
51 | typedef struct MountPoint { |
52 | const char *what; | |
53 | const char *where; | |
54 | const char *type; | |
55 | const char *options; | |
56 | unsigned long flags; | |
6aa220e0 KS |
57 | bool (*condition_fn)(void); |
58 | MountMode mode; | |
ca714c0e LP |
59 | } MountPoint; |
60 | ||
4ef31082 | 61 | /* The first three entries we might need before SELinux is up. The |
160481f6 | 62 | * fourth (securityfs) is needed by IMA to load a custom policy. The |
7c96ab1d LP |
63 | * other ones we can delay until SELinux and IMA are loaded. When |
64 | * SMACK is enabled we need smackfs, too, so it's a fifth one. */ | |
65 | #ifdef HAVE_SMACK | |
ffbd2c4d | 66 | #define N_EARLY_MOUNT 5 |
7c96ab1d LP |
67 | #else |
68 | #define N_EARLY_MOUNT 4 | |
69 | #endif | |
4ef31082 | 70 | |
ca714c0e | 71 | static const MountPoint mount_table[] = { |
68d4c452 LP |
72 | { "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
73 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
74 | { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
75 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
76 | { "devtmpfs", "/dev", "devtmpfs", "mode=755", MS_NOSUID|MS_STRICTATIME, | |
77 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
78 | { "securityfs", "/sys/kernel/security", "securityfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
79 | NULL, MNT_NONE }, | |
d407c940 | 80 | #ifdef HAVE_SMACK |
68d4c452 LP |
81 | { "smackfs", "/sys/fs/smackfs", "smackfs", "smackfsdef=*", MS_NOSUID|MS_NOEXEC|MS_NODEV, |
82 | mac_smack_use, MNT_FATAL }, | |
83 | { "tmpfs", "/dev/shm", "tmpfs", "mode=1777,smackfsroot=*", MS_NOSUID|MS_NODEV|MS_STRICTATIME, | |
84 | mac_smack_use, MNT_FATAL }, | |
d407c940 | 85 | #endif |
68d4c452 LP |
86 | { "tmpfs", "/dev/shm", "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV|MS_STRICTATIME, |
87 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
88 | { "devpts", "/dev/pts", "devpts", "mode=620,gid=" STRINGIFY(TTY_GID), MS_NOSUID|MS_NOEXEC, | |
89 | NULL, MNT_IN_CONTAINER }, | |
d407c940 | 90 | #ifdef HAVE_SMACK |
68d4c452 LP |
91 | { "tmpfs", "/run", "tmpfs", "mode=755,smackfsroot=*", MS_NOSUID|MS_NODEV|MS_STRICTATIME, |
92 | mac_smack_use, MNT_FATAL }, | |
d407c940 | 93 | #endif |
68d4c452 LP |
94 | { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID|MS_NODEV|MS_STRICTATIME, |
95 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
efdb0237 LP |
96 | { "cgroup", "/sys/fs/cgroup", "cgroup", "__DEVEL__sane_behavior", MS_NOSUID|MS_NOEXEC|MS_NODEV, |
97 | cg_is_unified_wanted, MNT_FATAL|MNT_IN_CONTAINER }, | |
68d4c452 | 98 | { "tmpfs", "/sys/fs/cgroup", "tmpfs", "mode=755", MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, |
efdb0237 | 99 | cg_is_legacy_wanted, MNT_FATAL|MNT_IN_CONTAINER }, |
68d4c452 | 100 | { "cgroup", "/sys/fs/cgroup/systemd", "cgroup", "none,name=systemd,xattr", MS_NOSUID|MS_NOEXEC|MS_NODEV, |
efdb0237 | 101 | cg_is_legacy_wanted, MNT_IN_CONTAINER }, |
68d4c452 | 102 | { "cgroup", "/sys/fs/cgroup/systemd", "cgroup", "none,name=systemd", MS_NOSUID|MS_NOEXEC|MS_NODEV, |
efdb0237 | 103 | cg_is_legacy_wanted, MNT_FATAL|MNT_IN_CONTAINER }, |
68d4c452 LP |
104 | { "pstore", "/sys/fs/pstore", "pstore", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
105 | NULL, MNT_NONE }, | |
c06bf414 | 106 | #ifdef ENABLE_EFI |
68d4c452 LP |
107 | { "efivarfs", "/sys/firmware/efi/efivars", "efivarfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
108 | is_efi_boot, MNT_NONE }, | |
c06bf414 | 109 | #endif |
63cc4c31 | 110 | { "kdbusfs", "/sys/fs/kdbus", "kdbusfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
1f49dffc | 111 | is_kdbus_wanted, MNT_IN_CONTAINER }, |
63cc4c31 DM |
112 | }; |
113 | ||
949c6510 | 114 | /* These are API file systems that might be mounted by other software, |
46ff0ed7 | 115 | * we just list them here so that we know that we should ignore them */ |
949c6510 | 116 | |
eaeb18db LP |
117 | static const char ignore_paths[] = |
118 | /* SELinux file systems */ | |
119 | "/sys/fs/selinux\0" | |
eaeb18db LP |
120 | /* Container bind mounts */ |
121 | "/proc/sys\0" | |
122 | "/dev/console\0" | |
c481f78b | 123 | "/proc/kmsg\0"; |
949c6510 | 124 | |
dad08730 LP |
125 | bool mount_point_is_api(const char *path) { |
126 | unsigned i; | |
127 | ||
128 | /* Checks if this mount point is considered "API", and hence | |
129 | * should be ignored */ | |
130 | ||
ca714c0e | 131 | for (i = 0; i < ELEMENTSOF(mount_table); i ++) |
449ddb2d | 132 | if (path_equal(path, mount_table[i].where)) |
dad08730 LP |
133 | return true; |
134 | ||
57f2a956 KS |
135 | return path_startswith(path, "/sys/fs/cgroup/"); |
136 | } | |
137 | ||
138 | bool mount_point_ignore(const char *path) { | |
eaeb18db | 139 | const char *i; |
57f2a956 | 140 | |
eaeb18db LP |
141 | NULSTR_FOREACH(i, ignore_paths) |
142 | if (path_equal(path, i)) | |
949c6510 LP |
143 | return true; |
144 | ||
57f2a956 | 145 | return false; |
dad08730 LP |
146 | } |
147 | ||
4ef31082 | 148 | static int mount_one(const MountPoint *p, bool relabel) { |
8e274523 LP |
149 | int r; |
150 | ||
ca714c0e | 151 | assert(p); |
8e274523 | 152 | |
6aa220e0 KS |
153 | if (p->condition_fn && !p->condition_fn()) |
154 | return 0; | |
155 | ||
51b4af2c | 156 | /* Relabel first, just in case */ |
4ef31082 | 157 | if (relabel) |
c9bc0764 | 158 | label_fix(p->where, true, true); |
51b4af2c | 159 | |
e26d6ce5 | 160 | r = path_is_mount_point(p->where, AT_SYMLINK_FOLLOW); |
64f75d7a | 161 | if (r < 0 && r != -ENOENT) |
8e274523 | 162 | return r; |
8e274523 | 163 | if (r > 0) |
51b4af2c | 164 | return 0; |
8e274523 | 165 | |
c481f78b | 166 | /* Skip securityfs in a container */ |
6aa220e0 | 167 | if (!(p->mode & MNT_IN_CONTAINER) && detect_container(NULL) > 0) |
c481f78b LP |
168 | return 0; |
169 | ||
a04f58d6 LP |
170 | /* The access mode here doesn't really matter too much, since |
171 | * the mounted file system will take precedence anyway. */ | |
c4bfd169 LP |
172 | if (relabel) |
173 | mkdir_p_label(p->where, 0755); | |
174 | else | |
175 | mkdir_p(p->where, 0755); | |
a04f58d6 | 176 | |
8e274523 | 177 | log_debug("Mounting %s to %s of type %s with options %s.", |
ca714c0e LP |
178 | p->what, |
179 | p->where, | |
180 | p->type, | |
181 | strna(p->options)); | |
182 | ||
183 | if (mount(p->what, | |
184 | p->where, | |
185 | p->type, | |
186 | p->flags, | |
187 | p->options) < 0) { | |
99a17ada | 188 | log_full((p->mode & MNT_FATAL) ? LOG_ERR : LOG_DEBUG, "Failed to mount %s at %s: %m", p->type, p->where); |
6aa220e0 | 189 | return (p->mode & MNT_FATAL) ? -errno : 0; |
8e274523 LP |
190 | } |
191 | ||
51b4af2c | 192 | /* Relabel again, since we now mounted something fresh here */ |
4ef31082 | 193 | if (relabel) |
c9bc0764 | 194 | label_fix(p->where, false, false); |
5275d3c1 | 195 | |
0c85a4f3 | 196 | return 1; |
8e274523 LP |
197 | } |
198 | ||
4ef31082 LP |
199 | int mount_setup_early(void) { |
200 | unsigned i; | |
201 | int r = 0; | |
202 | ||
203 | assert_cc(N_EARLY_MOUNT <= ELEMENTSOF(mount_table)); | |
204 | ||
205 | /* Do a minimal mount of /proc and friends to enable the most | |
206 | * basic stuff, such as SELinux */ | |
207 | for (i = 0; i < N_EARLY_MOUNT; i ++) { | |
208 | int j; | |
209 | ||
210 | j = mount_one(mount_table + i, false); | |
211 | if (r == 0) | |
212 | r = j; | |
213 | } | |
214 | ||
215 | return r; | |
216 | } | |
217 | ||
0c85a4f3 | 218 | int mount_cgroup_controllers(char ***join_controllers) { |
a6b26d90 | 219 | _cleanup_set_free_free_ Set *controllers = NULL; |
a641dcd9 | 220 | int r; |
2076ca54 | 221 | |
efdb0237 LP |
222 | if (!cg_is_legacy_wanted()) |
223 | return 0; | |
224 | ||
670802d4 | 225 | /* Mount all available cgroup controllers that are built into the kernel. */ |
2076ca54 | 226 | |
d5099efc | 227 | controllers = set_new(&string_hash_ops); |
a6b26d90 ZJS |
228 | if (!controllers) |
229 | return log_oom(); | |
0c85a4f3 | 230 | |
b12afc8c LP |
231 | r = cg_kernel_controllers(controllers); |
232 | if (r < 0) | |
233 | return log_error_errno(r, "Failed to enumerate cgroup controllers: %m"); | |
0c85a4f3 LP |
234 | |
235 | for (;;) { | |
a641dcd9 | 236 | _cleanup_free_ char *options = NULL, *controller = NULL, *where = NULL; |
a6b26d90 ZJS |
237 | MountPoint p = { |
238 | .what = "cgroup", | |
239 | .type = "cgroup", | |
240 | .flags = MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
241 | .mode = MNT_IN_CONTAINER, | |
242 | }; | |
0c85a4f3 LP |
243 | char ***k = NULL; |
244 | ||
245 | controller = set_steal_first(controllers); | |
246 | if (!controller) | |
247 | break; | |
248 | ||
249 | if (join_controllers) | |
250 | for (k = join_controllers; *k; k++) | |
251 | if (strv_find(*k, controller)) | |
252 | break; | |
253 | ||
254 | if (k && *k) { | |
255 | char **i, **j; | |
256 | ||
257 | for (i = *k, j = *k; *i; i++) { | |
258 | ||
259 | if (!streq(*i, controller)) { | |
a641dcd9 | 260 | _cleanup_free_ char *t; |
0c85a4f3 LP |
261 | |
262 | t = set_remove(controllers, *i); | |
263 | if (!t) { | |
264 | free(*i); | |
265 | continue; | |
266 | } | |
0c85a4f3 LP |
267 | } |
268 | ||
269 | *(j++) = *i; | |
270 | } | |
271 | ||
272 | *j = NULL; | |
273 | ||
274 | options = strv_join(*k, ","); | |
a6b26d90 ZJS |
275 | if (!options) |
276 | return log_oom(); | |
0c85a4f3 LP |
277 | } else { |
278 | options = controller; | |
279 | controller = NULL; | |
280 | } | |
281 | ||
a641dcd9 LP |
282 | where = strappend("/sys/fs/cgroup/", options); |
283 | if (!where) | |
284 | return log_oom(); | |
285 | ||
286 | p.where = where; | |
0c85a4f3 | 287 | p.options = options; |
2076ca54 | 288 | |
4ef31082 | 289 | r = mount_one(&p, true); |
a6b26d90 ZJS |
290 | if (r < 0) |
291 | return r; | |
0c85a4f3 LP |
292 | |
293 | if (r > 0 && k && *k) { | |
294 | char **i; | |
295 | ||
296 | for (i = *k; *i; i++) { | |
a641dcd9 LP |
297 | _cleanup_free_ char *t = NULL; |
298 | ||
299 | t = strappend("/sys/fs/cgroup/", *i); | |
300 | if (!t) | |
301 | return log_oom(); | |
0c85a4f3 LP |
302 | |
303 | r = symlink(options, t); | |
4a62c710 MS |
304 | if (r < 0 && errno != EEXIST) |
305 | return log_error_errno(errno, "Failed to create symlink %s: %m", t); | |
0c85a4f3 LP |
306 | } |
307 | } | |
2076ca54 LP |
308 | } |
309 | ||
679142ce LP |
310 | /* Now that we mounted everything, let's make the tmpfs the |
311 | * cgroup file systems are mounted into read-only. */ | |
b12afc8c | 312 | (void) mount("tmpfs", "/sys/fs/cgroup", "tmpfs", MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY, "mode=755"); |
679142ce | 313 | |
a6b26d90 | 314 | return 0; |
2076ca54 LP |
315 | } |
316 | ||
0fff82e5 | 317 | #if defined(HAVE_SELINUX) || defined(HAVE_SMACK) |
1829dc9d LP |
318 | static int nftw_cb( |
319 | const char *fpath, | |
320 | const struct stat *sb, | |
321 | int tflag, | |
322 | struct FTW *ftwbuf) { | |
323 | ||
9fe117ea | 324 | /* No need to label /dev twice in a row... */ |
edb49778 LP |
325 | if (_unlikely_(ftwbuf->level == 0)) |
326 | return FTW_CONTINUE; | |
327 | ||
c9bc0764 | 328 | label_fix(fpath, false, false); |
af65c248 | 329 | |
edb49778 | 330 | /* /run/initramfs is static data and big, no need to |
af65c248 | 331 | * dynamically relabel its contents at boot... */ |
edb49778 LP |
332 | if (_unlikely_(ftwbuf->level == 1 && |
333 | tflag == FTW_D && | |
334 | streq(fpath, "/run/initramfs"))) | |
335 | return FTW_SKIP_SUBTREE; | |
9fe117ea | 336 | |
edb49778 | 337 | return FTW_CONTINUE; |
1829dc9d | 338 | }; |
0fff82e5 | 339 | #endif |
1829dc9d | 340 | |
0b3325e7 | 341 | int mount_setup(bool loaded_policy) { |
dad08730 | 342 | unsigned i; |
68d4c452 | 343 | int r = 0; |
8e274523 | 344 | |
4ef31082 | 345 | for (i = 0; i < ELEMENTSOF(mount_table); i ++) { |
68d4c452 | 346 | int j; |
4ef31082 | 347 | |
68d4c452 LP |
348 | j = mount_one(mount_table + i, loaded_policy); |
349 | if (r == 0) | |
350 | r = j; | |
4ef31082 | 351 | } |
8e274523 | 352 | |
68d4c452 LP |
353 | if (r < 0) |
354 | return r; | |
355 | ||
0fff82e5 | 356 | #if defined(HAVE_SELINUX) || defined(HAVE_SMACK) |
f1d19aa4 LP |
357 | /* Nodes in devtmpfs and /run need to be manually updated for |
358 | * the appropriate labels, after mounting. The other virtual | |
359 | * API file systems like /sys and /proc do not need that, they | |
360 | * use the same label for all their files. */ | |
0b3325e7 LP |
361 | if (loaded_policy) { |
362 | usec_t before_relabel, after_relabel; | |
363 | char timespan[FORMAT_TIMESPAN_MAX]; | |
364 | ||
365 | before_relabel = now(CLOCK_MONOTONIC); | |
366 | ||
edb49778 LP |
367 | nftw("/dev", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL); |
368 | nftw("/run", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL); | |
0b3325e7 LP |
369 | |
370 | after_relabel = now(CLOCK_MONOTONIC); | |
371 | ||
372 | log_info("Relabelled /dev and /run in %s.", | |
2fa4092c | 373 | format_timespan(timespan, sizeof(timespan), after_relabel - before_relabel, 0)); |
3bbecb2f | 374 | } |
0fff82e5 | 375 | #endif |
1829dc9d | 376 | |
5c0532d1 | 377 | /* Create a few default symlinks, which are normally created |
f1d19aa4 | 378 | * by udevd, but some scripts might need them before we start |
5c0532d1 | 379 | * udevd. */ |
03cfe0d5 | 380 | dev_setup(NULL, UID_INVALID, GID_INVALID); |
5c0532d1 | 381 | |
b3ac5f8c LP |
382 | /* Mark the root directory as shared in regards to mount |
383 | * propagation. The kernel defaults to "private", but we think | |
384 | * it makes more sense to have a default of "shared" so that | |
385 | * nspawn and the container tools work out of the box. If | |
386 | * specific setups need other settings they can reset the | |
387 | * propagation mode to private if needed. */ | |
c481f78b LP |
388 | if (detect_container(NULL) <= 0) |
389 | if (mount(NULL, "/", NULL, MS_REC|MS_SHARED, NULL) < 0) | |
56f64d95 | 390 | log_warning_errno(errno, "Failed to set up the root directory for shared mount propagation: %m"); |
b3ac5f8c | 391 | |
66e41181 LP |
392 | /* Create a few directories we always want around, Note that |
393 | * sd_booted() checks for /run/systemd/system, so this mkdir | |
394 | * really needs to stay for good, otherwise software that | |
395 | * copied sd-daemon.c into their sources will misdetect | |
396 | * systemd. */ | |
d2e54fae KS |
397 | mkdir_label("/run/systemd", 0755); |
398 | mkdir_label("/run/systemd/system", 0755); | |
c17ec25e | 399 | mkdir_label("/run/systemd/inaccessible", 0000); |
b925e726 | 400 | |
0c85a4f3 | 401 | return 0; |
8e274523 | 402 | } |