]>
Commit | Line | Data |
---|---|---|
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 | |
9 | under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
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 | |
16 | General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
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" | |
33 | #include "log.h" | |
c9af1080 LP |
34 | #include "macro.h" |
35 | #include "util.h" | |
5275d3c1 | 36 | #include "label.h" |
0c85a4f3 LP |
37 | #include "set.h" |
38 | #include "strv.h" | |
8e274523 | 39 | |
bef2733f LP |
40 | #ifndef TTY_GID |
41 | #define TTY_GID 5 | |
42 | #endif | |
43 | ||
ca714c0e LP |
44 | typedef struct MountPoint { |
45 | const char *what; | |
46 | const char *where; | |
47 | const char *type; | |
48 | const char *options; | |
49 | unsigned long flags; | |
2076ca54 | 50 | bool fatal; |
ca714c0e LP |
51 | } MountPoint; |
52 | ||
4ef31082 LP |
53 | /* The first three entries we might need before SELinux is up. The |
54 | * other ones we can delay until SELinux is loaded. */ | |
55 | #define N_EARLY_MOUNT 3 | |
56 | ||
ca714c0e | 57 | static const MountPoint mount_table[] = { |
77d5f105 LP |
58 | { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, true }, |
59 | { "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, true }, | |
60 | { "devtmpfs", "/dev", "devtmpfs", "mode=755", MS_NOSUID, true }, | |
501c875b | 61 | { "tmpfs", "/dev/shm", "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV, true }, |
bef2733f | 62 | { "devpts", "/dev/pts", "devpts", "mode=620,gid=" STRINGIFY(TTY_GID), MS_NOSUID|MS_NOEXEC, false }, |
fbe092cc | 63 | { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID|MS_NODEV, true }, |
e5a53dc7 LP |
64 | { "tmpfs", "/sys/fs/cgroup", "tmpfs", "mode=755", MS_NOSUID|MS_NOEXEC|MS_NODEV, false }, |
65 | { "cgroup", "/sys/fs/cgroup/systemd", "cgroup", "none,name=systemd", MS_NOSUID|MS_NOEXEC|MS_NODEV, false }, | |
8e274523 LP |
66 | }; |
67 | ||
949c6510 | 68 | /* These are API file systems that might be mounted by other software, |
46ff0ed7 | 69 | * we just list them here so that we know that we should ignore them */ |
949c6510 LP |
70 | |
71 | static const char * const ignore_paths[] = { | |
ef9d7dca | 72 | "/sys/fs/selinux", |
949c6510 | 73 | "/selinux", |
af49ec2c | 74 | "/proc/bus/usb" |
949c6510 LP |
75 | }; |
76 | ||
dad08730 LP |
77 | bool mount_point_is_api(const char *path) { |
78 | unsigned i; | |
79 | ||
80 | /* Checks if this mount point is considered "API", and hence | |
81 | * should be ignored */ | |
82 | ||
ca714c0e | 83 | for (i = 0; i < ELEMENTSOF(mount_table); i ++) |
449ddb2d | 84 | if (path_equal(path, mount_table[i].where)) |
dad08730 LP |
85 | return true; |
86 | ||
57f2a956 KS |
87 | return path_startswith(path, "/sys/fs/cgroup/"); |
88 | } | |
89 | ||
90 | bool mount_point_ignore(const char *path) { | |
46ff0ed7 | 91 | unsigned i; |
57f2a956 | 92 | |
949c6510 | 93 | for (i = 0; i < ELEMENTSOF(ignore_paths); i++) |
449ddb2d | 94 | if (path_equal(path, ignore_paths[i])) |
949c6510 LP |
95 | return true; |
96 | ||
57f2a956 | 97 | return false; |
dad08730 LP |
98 | } |
99 | ||
4ef31082 | 100 | static int mount_one(const MountPoint *p, bool relabel) { |
8e274523 LP |
101 | int r; |
102 | ||
ca714c0e | 103 | assert(p); |
8e274523 | 104 | |
51b4af2c | 105 | /* Relabel first, just in case */ |
4ef31082 LP |
106 | if (relabel) |
107 | label_fix(p->where, true); | |
51b4af2c | 108 | |
0c85a4f3 | 109 | if ((r = path_is_mount_point(p->where, true)) < 0) |
8e274523 LP |
110 | return r; |
111 | ||
112 | if (r > 0) | |
51b4af2c | 113 | return 0; |
8e274523 | 114 | |
a04f58d6 LP |
115 | /* The access mode here doesn't really matter too much, since |
116 | * the mounted file system will take precedence anyway. */ | |
ca714c0e | 117 | mkdir_p(p->where, 0755); |
a04f58d6 | 118 | |
8e274523 | 119 | log_debug("Mounting %s to %s of type %s with options %s.", |
ca714c0e LP |
120 | p->what, |
121 | p->where, | |
122 | p->type, | |
123 | strna(p->options)); | |
124 | ||
125 | if (mount(p->what, | |
126 | p->where, | |
127 | p->type, | |
128 | p->flags, | |
129 | p->options) < 0) { | |
130 | log_error("Failed to mount %s: %s", p->where, strerror(errno)); | |
2076ca54 | 131 | return p->fatal ? -errno : 0; |
8e274523 LP |
132 | } |
133 | ||
51b4af2c | 134 | /* Relabel again, since we now mounted something fresh here */ |
4ef31082 LP |
135 | if (relabel) |
136 | label_fix(p->where, false); | |
5275d3c1 | 137 | |
0c85a4f3 | 138 | return 1; |
8e274523 LP |
139 | } |
140 | ||
4ef31082 LP |
141 | int mount_setup_early(void) { |
142 | unsigned i; | |
143 | int r = 0; | |
144 | ||
145 | assert_cc(N_EARLY_MOUNT <= ELEMENTSOF(mount_table)); | |
146 | ||
147 | /* Do a minimal mount of /proc and friends to enable the most | |
148 | * basic stuff, such as SELinux */ | |
149 | for (i = 0; i < N_EARLY_MOUNT; i ++) { | |
150 | int j; | |
151 | ||
152 | j = mount_one(mount_table + i, false); | |
153 | if (r == 0) | |
154 | r = j; | |
155 | } | |
156 | ||
157 | return r; | |
158 | } | |
159 | ||
0c85a4f3 | 160 | int mount_cgroup_controllers(char ***join_controllers) { |
2076ca54 LP |
161 | int r; |
162 | FILE *f; | |
20c03b7b | 163 | char buf[LINE_MAX]; |
0c85a4f3 | 164 | Set *controllers; |
2076ca54 | 165 | |
670802d4 | 166 | /* Mount all available cgroup controllers that are built into the kernel. */ |
2076ca54 | 167 | |
0c85a4f3 LP |
168 | f = fopen("/proc/cgroups", "re"); |
169 | if (!f) { | |
016e9849 LP |
170 | log_error("Failed to enumerate cgroup controllers: %m"); |
171 | return 0; | |
172 | } | |
2076ca54 | 173 | |
0c85a4f3 LP |
174 | controllers = set_new(string_hash_func, string_compare_func); |
175 | if (!controllers) { | |
176 | r = -ENOMEM; | |
177 | log_error("Failed to allocate controller set."); | |
178 | goto finish; | |
179 | } | |
180 | ||
2076ca54 | 181 | /* Ignore the header line */ |
bab45044 | 182 | (void) fgets(buf, sizeof(buf), f); |
2076ca54 LP |
183 | |
184 | for (;;) { | |
0c85a4f3 LP |
185 | char *controller; |
186 | int enabled = 0; | |
2076ca54 | 187 | |
16f6682d | 188 | if (fscanf(f, "%ms %*i %*i %i", &controller, &enabled) != 2) { |
2076ca54 LP |
189 | |
190 | if (feof(f)) | |
191 | break; | |
192 | ||
193 | log_error("Failed to parse /proc/cgroups."); | |
194 | r = -EIO; | |
195 | goto finish; | |
196 | } | |
197 | ||
600a328f LP |
198 | if (!enabled) { |
199 | free(controller); | |
200 | continue; | |
201 | } | |
202 | ||
0c85a4f3 LP |
203 | r = set_put(controllers, controller); |
204 | if (r < 0) { | |
205 | log_error("Failed to add controller to set."); | |
2076ca54 | 206 | free(controller); |
0c85a4f3 LP |
207 | goto finish; |
208 | } | |
209 | } | |
210 | ||
211 | for (;;) { | |
212 | MountPoint p; | |
213 | char *controller, *where, *options; | |
214 | char ***k = NULL; | |
215 | ||
216 | controller = set_steal_first(controllers); | |
217 | if (!controller) | |
218 | break; | |
219 | ||
220 | if (join_controllers) | |
221 | for (k = join_controllers; *k; k++) | |
222 | if (strv_find(*k, controller)) | |
223 | break; | |
224 | ||
225 | if (k && *k) { | |
226 | char **i, **j; | |
227 | ||
228 | for (i = *k, j = *k; *i; i++) { | |
229 | ||
230 | if (!streq(*i, controller)) { | |
231 | char *t; | |
232 | ||
233 | t = set_remove(controllers, *i); | |
234 | if (!t) { | |
235 | free(*i); | |
236 | continue; | |
237 | } | |
238 | free(t); | |
239 | } | |
240 | ||
241 | *(j++) = *i; | |
242 | } | |
243 | ||
244 | *j = NULL; | |
245 | ||
246 | options = strv_join(*k, ","); | |
247 | if (!options) { | |
248 | log_error("Failed to join options"); | |
249 | free(controller); | |
250 | r = -ENOMEM; | |
251 | goto finish; | |
252 | } | |
253 | ||
254 | } else { | |
255 | options = controller; | |
256 | controller = NULL; | |
257 | } | |
258 | ||
259 | where = strappend("/sys/fs/cgroup/", options); | |
260 | if (!where) { | |
261 | log_error("Failed to build path"); | |
262 | free(options); | |
2076ca54 LP |
263 | r = -ENOMEM; |
264 | goto finish; | |
265 | } | |
266 | ||
267 | zero(p); | |
268 | p.what = "cgroup"; | |
269 | p.where = where; | |
270 | p.type = "cgroup"; | |
0c85a4f3 | 271 | p.options = options; |
2076ca54 LP |
272 | p.flags = MS_NOSUID|MS_NOEXEC|MS_NODEV; |
273 | p.fatal = false; | |
274 | ||
4ef31082 | 275 | r = mount_one(&p, true); |
2076ca54 LP |
276 | free(controller); |
277 | free(where); | |
278 | ||
0c85a4f3 LP |
279 | if (r < 0) { |
280 | free(options); | |
2076ca54 | 281 | goto finish; |
0c85a4f3 LP |
282 | } |
283 | ||
284 | if (r > 0 && k && *k) { | |
285 | char **i; | |
286 | ||
287 | for (i = *k; *i; i++) { | |
288 | char *t; | |
289 | ||
290 | t = strappend("/sys/fs/cgroup/", *i); | |
291 | if (!t) { | |
292 | log_error("Failed to build path"); | |
293 | r = -ENOMEM; | |
294 | free(options); | |
295 | goto finish; | |
296 | } | |
297 | ||
298 | r = symlink(options, t); | |
299 | free(t); | |
300 | ||
301 | if (r < 0 && errno != EEXIST) { | |
302 | log_error("Failed to create symlink: %m"); | |
303 | r = -errno; | |
304 | free(options); | |
305 | goto finish; | |
306 | } | |
307 | } | |
308 | } | |
309 | ||
310 | free(options); | |
2076ca54 LP |
311 | } |
312 | ||
313 | r = 0; | |
314 | ||
315 | finish: | |
0c85a4f3 LP |
316 | set_free_free(controllers); |
317 | ||
2076ca54 LP |
318 | fclose(f); |
319 | ||
320 | return r; | |
321 | } | |
322 | ||
5c0532d1 LP |
323 | static int symlink_and_label(const char *old_path, const char *new_path) { |
324 | int r; | |
325 | ||
326 | assert(old_path); | |
327 | assert(new_path); | |
328 | ||
329 | if ((r = label_symlinkfile_set(new_path)) < 0) | |
330 | return r; | |
331 | ||
332 | if (symlink(old_path, new_path) < 0) | |
333 | r = -errno; | |
334 | ||
335 | label_file_clear(); | |
336 | ||
337 | return r; | |
338 | } | |
339 | ||
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 | ||
af65c248 LP |
350 | label_fix(fpath, true); |
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 LP |
360 | }; |
361 | ||
0b3325e7 | 362 | int mount_setup(bool loaded_policy) { |
5c0532d1 | 363 | |
af65c248 | 364 | static const char symlinks[] = |
5c0532d1 LP |
365 | "/proc/kcore\0" "/dev/core\0" |
366 | "/proc/self/fd\0" "/dev/fd\0" | |
367 | "/proc/self/fd/0\0" "/dev/stdin\0" | |
368 | "/proc/self/fd/1\0" "/dev/stdout\0" | |
34df5a34 | 369 | "/proc/self/fd/2\0" "/dev/stderr\0"; |
5c0532d1 | 370 | |
af65c248 LP |
371 | static const char relabel[] = |
372 | "/run/initramfs/root-fsck\0" | |
373 | "/run/initramfs/shutdown\0"; | |
374 | ||
8e274523 | 375 | int r; |
dad08730 | 376 | unsigned i; |
5c0532d1 | 377 | const char *j, *k; |
8e274523 | 378 | |
4ef31082 LP |
379 | for (i = 0; i < ELEMENTSOF(mount_table); i ++) { |
380 | r = mount_one(mount_table + i, true); | |
381 | ||
382 | if (r < 0) | |
8e274523 | 383 | return r; |
4ef31082 | 384 | } |
8e274523 | 385 | |
f1d19aa4 LP |
386 | /* Nodes in devtmpfs and /run need to be manually updated for |
387 | * the appropriate labels, after mounting. The other virtual | |
388 | * API file systems like /sys and /proc do not need that, they | |
389 | * use the same label for all their files. */ | |
0b3325e7 LP |
390 | if (loaded_policy) { |
391 | usec_t before_relabel, after_relabel; | |
392 | char timespan[FORMAT_TIMESPAN_MAX]; | |
393 | ||
394 | before_relabel = now(CLOCK_MONOTONIC); | |
395 | ||
edb49778 LP |
396 | nftw("/dev", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL); |
397 | nftw("/run", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL); | |
0b3325e7 | 398 | |
af65c248 LP |
399 | /* Explicitly relabel these */ |
400 | NULSTR_FOREACH(j, relabel) | |
401 | label_fix(j, true); | |
402 | ||
0b3325e7 LP |
403 | after_relabel = now(CLOCK_MONOTONIC); |
404 | ||
405 | log_info("Relabelled /dev and /run in %s.", | |
406 | format_timespan(timespan, sizeof(timespan), after_relabel - before_relabel)); | |
3bbecb2f | 407 | } |
1829dc9d | 408 | |
5c0532d1 | 409 | /* Create a few default symlinks, which are normally created |
f1d19aa4 | 410 | * by udevd, but some scripts might need them before we start |
5c0532d1 | 411 | * udevd. */ |
5c0532d1 LP |
412 | NULSTR_FOREACH_PAIR(j, k, symlinks) |
413 | symlink_and_label(j, k); | |
414 | ||
b925e726 | 415 | /* Create a few directories we always want around */ |
af65c248 LP |
416 | label_mkdir("/run/systemd", 0755); |
417 | label_mkdir("/run/systemd/system", 0755); | |
b925e726 | 418 | |
0c85a4f3 | 419 | return 0; |
8e274523 | 420 | } |