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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> | |
24 | #include <sys/stat.h> | |
25 | #include <stdlib.h> | |
26 | #include <string.h> | |
27 | #include <libgen.h> | |
28 | #include <assert.h> | |
5c0532d1 | 29 | #include <unistd.h> |
1829dc9d | 30 | #include <ftw.h> |
8e274523 LP |
31 | |
32 | #include "mount-setup.h" | |
5ba2dc25 | 33 | #include "dev-setup.h" |
8e274523 | 34 | #include "log.h" |
c9af1080 LP |
35 | #include "macro.h" |
36 | #include "util.h" | |
5275d3c1 | 37 | #include "label.h" |
0c85a4f3 LP |
38 | #include "set.h" |
39 | #include "strv.h" | |
49e942b2 | 40 | #include "mkdir.h" |
9eb977db | 41 | #include "path-util.h" |
48ac500b | 42 | #include "missing.h" |
c481f78b | 43 | #include "virt.h" |
8e274523 | 44 | |
bef2733f LP |
45 | #ifndef TTY_GID |
46 | #define TTY_GID 5 | |
47 | #endif | |
48 | ||
6aa220e0 KS |
49 | typedef enum MountMode { |
50 | MNT_NONE = 0, | |
51 | MNT_FATAL = 1 << 0, | |
52 | MNT_IN_CONTAINER = 1 << 1, | |
53 | } MountMode; | |
54 | ||
ca714c0e LP |
55 | typedef struct MountPoint { |
56 | const char *what; | |
57 | const char *where; | |
58 | const char *type; | |
59 | const char *options; | |
60 | unsigned long flags; | |
6aa220e0 KS |
61 | bool (*condition_fn)(void); |
62 | MountMode mode; | |
ca714c0e LP |
63 | } MountPoint; |
64 | ||
4ef31082 | 65 | /* The first three entries we might need before SELinux is up. The |
160481f6 RS |
66 | * fourth (securityfs) is needed by IMA to load a custom policy. The |
67 | * other ones we can delay until SELinux and IMA are loaded. */ | |
68 | #define N_EARLY_MOUNT 4 | |
4ef31082 | 69 | |
ca714c0e | 70 | static const MountPoint mount_table[] = { |
6aa220e0 KS |
71 | { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
72 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
73 | { "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
74 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
75 | { "devtmpfs", "/dev", "devtmpfs", "mode=755", MS_NOSUID|MS_STRICTATIME, | |
76 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
77 | { "securityfs", "/sys/kernel/security", "securityfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
78 | NULL, MNT_NONE }, | |
79 | { "efivarfs", "/sys/firmware/efi/efivars", "efivarfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
80 | is_efiboot, MNT_NONE }, | |
81 | { "tmpfs", "/dev/shm", "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV|MS_STRICTATIME, | |
82 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
83 | { "devpts", "/dev/pts", "devpts", "mode=620,gid=" STRINGIFY(TTY_GID), MS_NOSUID|MS_NOEXEC, | |
84 | NULL, MNT_IN_CONTAINER }, | |
85 | { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID|MS_NODEV|MS_STRICTATIME, | |
86 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
87 | { "tmpfs", "/sys/fs/cgroup", "tmpfs", "mode=755", MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, | |
88 | NULL, MNT_IN_CONTAINER }, | |
89 | { "cgroup", "/sys/fs/cgroup/systemd", "cgroup", "none,name=systemd", MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
90 | NULL, MNT_IN_CONTAINER }, | |
8e274523 LP |
91 | }; |
92 | ||
949c6510 | 93 | /* These are API file systems that might be mounted by other software, |
46ff0ed7 | 94 | * we just list them here so that we know that we should ignore them */ |
949c6510 | 95 | |
eaeb18db LP |
96 | static const char ignore_paths[] = |
97 | /* SELinux file systems */ | |
98 | "/sys/fs/selinux\0" | |
99 | "/selinux\0" | |
100 | /* Legacy cgroup mount points */ | |
101 | "/dev/cgroup\0" | |
102 | "/cgroup\0" | |
103 | /* Legacy kernel file system */ | |
104 | "/proc/bus/usb\0" | |
105 | /* Container bind mounts */ | |
106 | "/proc/sys\0" | |
107 | "/dev/console\0" | |
c481f78b | 108 | "/proc/kmsg\0"; |
949c6510 | 109 | |
dad08730 LP |
110 | bool mount_point_is_api(const char *path) { |
111 | unsigned i; | |
112 | ||
113 | /* Checks if this mount point is considered "API", and hence | |
114 | * should be ignored */ | |
115 | ||
ca714c0e | 116 | for (i = 0; i < ELEMENTSOF(mount_table); i ++) |
449ddb2d | 117 | if (path_equal(path, mount_table[i].where)) |
dad08730 LP |
118 | return true; |
119 | ||
57f2a956 KS |
120 | return path_startswith(path, "/sys/fs/cgroup/"); |
121 | } | |
122 | ||
123 | bool mount_point_ignore(const char *path) { | |
eaeb18db | 124 | const char *i; |
57f2a956 | 125 | |
eaeb18db LP |
126 | NULSTR_FOREACH(i, ignore_paths) |
127 | if (path_equal(path, i)) | |
949c6510 LP |
128 | return true; |
129 | ||
57f2a956 | 130 | return false; |
dad08730 LP |
131 | } |
132 | ||
4ef31082 | 133 | static int mount_one(const MountPoint *p, bool relabel) { |
8e274523 LP |
134 | int r; |
135 | ||
ca714c0e | 136 | assert(p); |
8e274523 | 137 | |
6aa220e0 KS |
138 | if (p->condition_fn && !p->condition_fn()) |
139 | return 0; | |
140 | ||
51b4af2c | 141 | /* Relabel first, just in case */ |
4ef31082 | 142 | if (relabel) |
c9bc0764 | 143 | label_fix(p->where, true, true); |
51b4af2c | 144 | |
c481f78b LP |
145 | r = path_is_mount_point(p->where, true); |
146 | if (r < 0) | |
8e274523 LP |
147 | return r; |
148 | ||
149 | if (r > 0) | |
51b4af2c | 150 | return 0; |
8e274523 | 151 | |
c481f78b | 152 | /* Skip securityfs in a container */ |
6aa220e0 | 153 | if (!(p->mode & MNT_IN_CONTAINER) && detect_container(NULL) > 0) |
c481f78b LP |
154 | return 0; |
155 | ||
a04f58d6 LP |
156 | /* The access mode here doesn't really matter too much, since |
157 | * the mounted file system will take precedence anyway. */ | |
d2e54fae | 158 | mkdir_p_label(p->where, 0755); |
a04f58d6 | 159 | |
8e274523 | 160 | log_debug("Mounting %s to %s of type %s with options %s.", |
ca714c0e LP |
161 | p->what, |
162 | p->where, | |
163 | p->type, | |
164 | strna(p->options)); | |
165 | ||
166 | if (mount(p->what, | |
167 | p->where, | |
168 | p->type, | |
169 | p->flags, | |
170 | p->options) < 0) { | |
6aa220e0 KS |
171 | log_full((p->mode & MNT_FATAL) ? LOG_ERR : LOG_DEBUG, "Failed to mount %s: %s", p->where, strerror(errno)); |
172 | return (p->mode & MNT_FATAL) ? -errno : 0; | |
8e274523 LP |
173 | } |
174 | ||
51b4af2c | 175 | /* Relabel again, since we now mounted something fresh here */ |
4ef31082 | 176 | if (relabel) |
c9bc0764 | 177 | label_fix(p->where, false, false); |
5275d3c1 | 178 | |
0c85a4f3 | 179 | return 1; |
8e274523 LP |
180 | } |
181 | ||
4ef31082 LP |
182 | int mount_setup_early(void) { |
183 | unsigned i; | |
184 | int r = 0; | |
185 | ||
186 | assert_cc(N_EARLY_MOUNT <= ELEMENTSOF(mount_table)); | |
187 | ||
188 | /* Do a minimal mount of /proc and friends to enable the most | |
189 | * basic stuff, such as SELinux */ | |
190 | for (i = 0; i < N_EARLY_MOUNT; i ++) { | |
191 | int j; | |
192 | ||
193 | j = mount_one(mount_table + i, false); | |
194 | if (r == 0) | |
195 | r = j; | |
196 | } | |
197 | ||
198 | return r; | |
199 | } | |
200 | ||
0c85a4f3 | 201 | int mount_cgroup_controllers(char ***join_controllers) { |
2076ca54 LP |
202 | int r; |
203 | FILE *f; | |
20c03b7b | 204 | char buf[LINE_MAX]; |
0c85a4f3 | 205 | Set *controllers; |
2076ca54 | 206 | |
670802d4 | 207 | /* Mount all available cgroup controllers that are built into the kernel. */ |
2076ca54 | 208 | |
0c85a4f3 LP |
209 | f = fopen("/proc/cgroups", "re"); |
210 | if (!f) { | |
016e9849 LP |
211 | log_error("Failed to enumerate cgroup controllers: %m"); |
212 | return 0; | |
213 | } | |
2076ca54 | 214 | |
0c85a4f3 LP |
215 | controllers = set_new(string_hash_func, string_compare_func); |
216 | if (!controllers) { | |
14212119 | 217 | r = log_oom(); |
0c85a4f3 LP |
218 | goto finish; |
219 | } | |
220 | ||
2076ca54 | 221 | /* Ignore the header line */ |
bab45044 | 222 | (void) fgets(buf, sizeof(buf), f); |
2076ca54 LP |
223 | |
224 | for (;;) { | |
0c85a4f3 LP |
225 | char *controller; |
226 | int enabled = 0; | |
2076ca54 | 227 | |
16f6682d | 228 | if (fscanf(f, "%ms %*i %*i %i", &controller, &enabled) != 2) { |
2076ca54 LP |
229 | |
230 | if (feof(f)) | |
231 | break; | |
232 | ||
233 | log_error("Failed to parse /proc/cgroups."); | |
234 | r = -EIO; | |
235 | goto finish; | |
236 | } | |
237 | ||
600a328f LP |
238 | if (!enabled) { |
239 | free(controller); | |
240 | continue; | |
241 | } | |
242 | ||
0c85a4f3 LP |
243 | r = set_put(controllers, controller); |
244 | if (r < 0) { | |
245 | log_error("Failed to add controller to set."); | |
2076ca54 | 246 | free(controller); |
0c85a4f3 LP |
247 | goto finish; |
248 | } | |
249 | } | |
250 | ||
251 | for (;;) { | |
252 | MountPoint p; | |
253 | char *controller, *where, *options; | |
254 | char ***k = NULL; | |
255 | ||
256 | controller = set_steal_first(controllers); | |
257 | if (!controller) | |
258 | break; | |
259 | ||
260 | if (join_controllers) | |
261 | for (k = join_controllers; *k; k++) | |
262 | if (strv_find(*k, controller)) | |
263 | break; | |
264 | ||
265 | if (k && *k) { | |
266 | char **i, **j; | |
267 | ||
268 | for (i = *k, j = *k; *i; i++) { | |
269 | ||
270 | if (!streq(*i, controller)) { | |
271 | char *t; | |
272 | ||
273 | t = set_remove(controllers, *i); | |
274 | if (!t) { | |
275 | free(*i); | |
276 | continue; | |
277 | } | |
278 | free(t); | |
279 | } | |
280 | ||
281 | *(j++) = *i; | |
282 | } | |
283 | ||
284 | *j = NULL; | |
285 | ||
286 | options = strv_join(*k, ","); | |
287 | if (!options) { | |
0c85a4f3 | 288 | free(controller); |
14212119 | 289 | r = log_oom(); |
0c85a4f3 LP |
290 | goto finish; |
291 | } | |
292 | ||
293 | } else { | |
294 | options = controller; | |
295 | controller = NULL; | |
296 | } | |
297 | ||
298 | where = strappend("/sys/fs/cgroup/", options); | |
299 | if (!where) { | |
0c85a4f3 | 300 | free(options); |
14212119 | 301 | r = log_oom(); |
2076ca54 LP |
302 | goto finish; |
303 | } | |
304 | ||
305 | zero(p); | |
306 | p.what = "cgroup"; | |
307 | p.where = where; | |
308 | p.type = "cgroup"; | |
0c85a4f3 | 309 | p.options = options; |
2076ca54 | 310 | p.flags = MS_NOSUID|MS_NOEXEC|MS_NODEV; |
2076ca54 | 311 | |
4ef31082 | 312 | r = mount_one(&p, true); |
2076ca54 LP |
313 | free(controller); |
314 | free(where); | |
315 | ||
0c85a4f3 LP |
316 | if (r < 0) { |
317 | free(options); | |
2076ca54 | 318 | goto finish; |
0c85a4f3 LP |
319 | } |
320 | ||
321 | if (r > 0 && k && *k) { | |
322 | char **i; | |
323 | ||
324 | for (i = *k; *i; i++) { | |
325 | char *t; | |
326 | ||
327 | t = strappend("/sys/fs/cgroup/", *i); | |
328 | if (!t) { | |
14212119 | 329 | r = log_oom(); |
0c85a4f3 LP |
330 | free(options); |
331 | goto finish; | |
332 | } | |
333 | ||
334 | r = symlink(options, t); | |
335 | free(t); | |
336 | ||
337 | if (r < 0 && errno != EEXIST) { | |
338 | log_error("Failed to create symlink: %m"); | |
339 | r = -errno; | |
340 | free(options); | |
341 | goto finish; | |
342 | } | |
343 | } | |
344 | } | |
345 | ||
346 | free(options); | |
2076ca54 LP |
347 | } |
348 | ||
349 | r = 0; | |
350 | ||
351 | finish: | |
0c85a4f3 LP |
352 | set_free_free(controllers); |
353 | ||
2076ca54 LP |
354 | fclose(f); |
355 | ||
356 | return r; | |
357 | } | |
358 | ||
1829dc9d LP |
359 | static int nftw_cb( |
360 | const char *fpath, | |
361 | const struct stat *sb, | |
362 | int tflag, | |
363 | struct FTW *ftwbuf) { | |
364 | ||
9fe117ea | 365 | /* No need to label /dev twice in a row... */ |
edb49778 LP |
366 | if (_unlikely_(ftwbuf->level == 0)) |
367 | return FTW_CONTINUE; | |
368 | ||
c9bc0764 | 369 | label_fix(fpath, false, false); |
af65c248 | 370 | |
edb49778 | 371 | /* /run/initramfs is static data and big, no need to |
af65c248 | 372 | * dynamically relabel its contents at boot... */ |
edb49778 LP |
373 | if (_unlikely_(ftwbuf->level == 1 && |
374 | tflag == FTW_D && | |
375 | streq(fpath, "/run/initramfs"))) | |
376 | return FTW_SKIP_SUBTREE; | |
9fe117ea | 377 | |
edb49778 | 378 | return FTW_CONTINUE; |
1829dc9d LP |
379 | }; |
380 | ||
0b3325e7 | 381 | int mount_setup(bool loaded_policy) { |
5c0532d1 | 382 | |
af65c248 LP |
383 | static const char relabel[] = |
384 | "/run/initramfs/root-fsck\0" | |
385 | "/run/initramfs/shutdown\0"; | |
386 | ||
8e274523 | 387 | int r; |
dad08730 | 388 | unsigned i; |
5ba2dc25 | 389 | const char *j; |
8e274523 | 390 | |
4ef31082 LP |
391 | for (i = 0; i < ELEMENTSOF(mount_table); i ++) { |
392 | r = mount_one(mount_table + i, true); | |
393 | ||
394 | if (r < 0) | |
8e274523 | 395 | return r; |
4ef31082 | 396 | } |
8e274523 | 397 | |
f1d19aa4 LP |
398 | /* Nodes in devtmpfs and /run need to be manually updated for |
399 | * the appropriate labels, after mounting. The other virtual | |
400 | * API file systems like /sys and /proc do not need that, they | |
401 | * use the same label for all their files. */ | |
0b3325e7 LP |
402 | if (loaded_policy) { |
403 | usec_t before_relabel, after_relabel; | |
404 | char timespan[FORMAT_TIMESPAN_MAX]; | |
405 | ||
406 | before_relabel = now(CLOCK_MONOTONIC); | |
407 | ||
edb49778 LP |
408 | nftw("/dev", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL); |
409 | nftw("/run", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL); | |
0b3325e7 | 410 | |
af65c248 LP |
411 | /* Explicitly relabel these */ |
412 | NULSTR_FOREACH(j, relabel) | |
c9bc0764 | 413 | label_fix(j, true, false); |
af65c248 | 414 | |
0b3325e7 LP |
415 | after_relabel = now(CLOCK_MONOTONIC); |
416 | ||
417 | log_info("Relabelled /dev and /run in %s.", | |
418 | format_timespan(timespan, sizeof(timespan), after_relabel - before_relabel)); | |
3bbecb2f | 419 | } |
1829dc9d | 420 | |
5c0532d1 | 421 | /* Create a few default symlinks, which are normally created |
f1d19aa4 | 422 | * by udevd, but some scripts might need them before we start |
5c0532d1 | 423 | * udevd. */ |
01ed0e23 | 424 | dev_setup(NULL); |
5c0532d1 | 425 | |
b3ac5f8c LP |
426 | /* Mark the root directory as shared in regards to mount |
427 | * propagation. The kernel defaults to "private", but we think | |
428 | * it makes more sense to have a default of "shared" so that | |
429 | * nspawn and the container tools work out of the box. If | |
430 | * specific setups need other settings they can reset the | |
431 | * propagation mode to private if needed. */ | |
c481f78b LP |
432 | if (detect_container(NULL) <= 0) |
433 | if (mount(NULL, "/", NULL, MS_REC|MS_SHARED, NULL) < 0) | |
434 | log_warning("Failed to set up the root directory for shared mount propagation: %m"); | |
b3ac5f8c | 435 | |
b925e726 | 436 | /* Create a few directories we always want around */ |
d2e54fae KS |
437 | mkdir_label("/run/systemd", 0755); |
438 | mkdir_label("/run/systemd/system", 0755); | |
b925e726 | 439 | |
0c85a4f3 | 440 | return 0; |
8e274523 | 441 | } |