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663996b3 MS |
1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
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 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. | |
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 | Lesser General Public License for more details. | |
17 | ||
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/>. | |
20 | ***/ | |
21 | ||
22 | #include <sys/mount.h> | |
23 | #include <errno.h> | |
663996b3 | 24 | #include <stdlib.h> |
663996b3 MS |
25 | #include <unistd.h> |
26 | #include <ftw.h> | |
27 | ||
28 | #include "mount-setup.h" | |
29 | #include "dev-setup.h" | |
30 | #include "log.h" | |
31 | #include "macro.h" | |
32 | #include "util.h" | |
33 | #include "label.h" | |
34 | #include "set.h" | |
35 | #include "strv.h" | |
36 | #include "mkdir.h" | |
37 | #include "path-util.h" | |
38 | #include "missing.h" | |
39 | #include "virt.h" | |
40 | #include "efivars.h" | |
60f067b4 | 41 | #include "smack-util.h" |
e735f4d4 | 42 | #include "cgroup-util.h" |
663996b3 MS |
43 | |
44 | typedef enum MountMode { | |
45 | MNT_NONE = 0, | |
46 | MNT_FATAL = 1 << 0, | |
47 | MNT_IN_CONTAINER = 1 << 1, | |
48 | } MountMode; | |
49 | ||
50 | typedef struct MountPoint { | |
51 | const char *what; | |
52 | const char *where; | |
53 | const char *type; | |
54 | const char *options; | |
55 | unsigned long flags; | |
56 | bool (*condition_fn)(void); | |
57 | MountMode mode; | |
58 | } MountPoint; | |
59 | ||
60 | /* The first three entries we might need before SELinux is up. The | |
61 | * fourth (securityfs) is needed by IMA to load a custom policy. The | |
5eef597e MP |
62 | * other ones we can delay until SELinux and IMA are loaded. When |
63 | * SMACK is enabled we need smackfs, too, so it's a fifth one. */ | |
64 | #ifdef HAVE_SMACK | |
663996b3 | 65 | #define N_EARLY_MOUNT 5 |
5eef597e MP |
66 | #else |
67 | #define N_EARLY_MOUNT 4 | |
68 | #endif | |
663996b3 MS |
69 | |
70 | static const MountPoint mount_table[] = { | |
f47781d8 MP |
71 | { "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
72 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
73 | { "proc", "/proc", "proc", 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 }, | |
60f067b4 | 79 | #ifdef HAVE_SMACK |
f47781d8 MP |
80 | { "smackfs", "/sys/fs/smackfs", "smackfs", "smackfsdef=*", MS_NOSUID|MS_NOEXEC|MS_NODEV, |
81 | mac_smack_use, MNT_FATAL }, | |
82 | { "tmpfs", "/dev/shm", "tmpfs", "mode=1777,smackfsroot=*", MS_NOSUID|MS_NODEV|MS_STRICTATIME, | |
83 | mac_smack_use, MNT_FATAL }, | |
60f067b4 | 84 | #endif |
f47781d8 MP |
85 | { "tmpfs", "/dev/shm", "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV|MS_STRICTATIME, |
86 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
87 | { "devpts", "/dev/pts", "devpts", "mode=620,gid=" STRINGIFY(TTY_GID), MS_NOSUID|MS_NOEXEC, | |
88 | NULL, MNT_IN_CONTAINER }, | |
60f067b4 | 89 | #ifdef HAVE_SMACK |
f47781d8 MP |
90 | { "tmpfs", "/run", "tmpfs", "mode=755,smackfsroot=*", MS_NOSUID|MS_NODEV|MS_STRICTATIME, |
91 | mac_smack_use, MNT_FATAL }, | |
60f067b4 | 92 | #endif |
f47781d8 MP |
93 | { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID|MS_NODEV|MS_STRICTATIME, |
94 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
95 | { "tmpfs", "/sys/fs/cgroup", "tmpfs", "mode=755", MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, | |
96 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
97 | { "cgroup", "/sys/fs/cgroup/systemd", "cgroup", "none,name=systemd,xattr", MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
98 | NULL, MNT_IN_CONTAINER }, | |
99 | { "cgroup", "/sys/fs/cgroup/systemd", "cgroup", "none,name=systemd", MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
100 | NULL, MNT_FATAL|MNT_IN_CONTAINER }, | |
101 | { "pstore", "/sys/fs/pstore", "pstore", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
102 | NULL, MNT_NONE }, | |
663996b3 | 103 | #ifdef ENABLE_EFI |
f47781d8 MP |
104 | { "efivarfs", "/sys/firmware/efi/efivars", "efivarfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
105 | is_efi_boot, MNT_NONE }, | |
106 | #endif | |
107 | #ifdef ENABLE_KDBUS | |
108 | { "kdbusfs", "/sys/fs/kdbus", "kdbusfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
109 | NULL, MNT_IN_CONTAINER }, | |
663996b3 MS |
110 | #endif |
111 | }; | |
112 | ||
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 */ | |
115 | ||
116 | static const char ignore_paths[] = | |
117 | /* SELinux file systems */ | |
118 | "/sys/fs/selinux\0" | |
663996b3 MS |
119 | /* Container bind mounts */ |
120 | "/proc/sys\0" | |
121 | "/dev/console\0" | |
122 | "/proc/kmsg\0"; | |
123 | ||
124 | bool mount_point_is_api(const char *path) { | |
125 | unsigned i; | |
126 | ||
127 | /* Checks if this mount point is considered "API", and hence | |
128 | * should be ignored */ | |
129 | ||
130 | for (i = 0; i < ELEMENTSOF(mount_table); i ++) | |
131 | if (path_equal(path, mount_table[i].where)) | |
132 | return true; | |
133 | ||
134 | return path_startswith(path, "/sys/fs/cgroup/"); | |
135 | } | |
136 | ||
137 | bool mount_point_ignore(const char *path) { | |
138 | const char *i; | |
139 | ||
140 | NULSTR_FOREACH(i, ignore_paths) | |
141 | if (path_equal(path, i)) | |
142 | return true; | |
143 | ||
144 | return false; | |
145 | } | |
146 | ||
147 | static int mount_one(const MountPoint *p, bool relabel) { | |
148 | int r; | |
149 | ||
150 | assert(p); | |
151 | ||
152 | if (p->condition_fn && !p->condition_fn()) | |
153 | return 0; | |
154 | ||
155 | /* Relabel first, just in case */ | |
156 | if (relabel) | |
157 | label_fix(p->where, true, true); | |
158 | ||
159 | r = path_is_mount_point(p->where, true); | |
e3bff60a | 160 | if (r < 0 && r != -ENOENT) |
663996b3 | 161 | return r; |
663996b3 MS |
162 | if (r > 0) |
163 | return 0; | |
164 | ||
165 | /* Skip securityfs in a container */ | |
166 | if (!(p->mode & MNT_IN_CONTAINER) && detect_container(NULL) > 0) | |
167 | return 0; | |
168 | ||
169 | /* The access mode here doesn't really matter too much, since | |
170 | * the mounted file system will take precedence anyway. */ | |
60f067b4 JS |
171 | if (relabel) |
172 | mkdir_p_label(p->where, 0755); | |
173 | else | |
174 | mkdir_p(p->where, 0755); | |
663996b3 MS |
175 | |
176 | log_debug("Mounting %s to %s of type %s with options %s.", | |
177 | p->what, | |
178 | p->where, | |
179 | p->type, | |
180 | strna(p->options)); | |
181 | ||
182 | if (mount(p->what, | |
183 | p->where, | |
184 | p->type, | |
185 | p->flags, | |
186 | p->options) < 0) { | |
60f067b4 | 187 | log_full((p->mode & MNT_FATAL) ? LOG_ERR : LOG_DEBUG, "Failed to mount %s at %s: %m", p->type, p->where); |
663996b3 MS |
188 | return (p->mode & MNT_FATAL) ? -errno : 0; |
189 | } | |
190 | ||
191 | /* Relabel again, since we now mounted something fresh here */ | |
192 | if (relabel) | |
193 | label_fix(p->where, false, false); | |
194 | ||
195 | return 1; | |
196 | } | |
197 | ||
198 | int mount_setup_early(void) { | |
199 | unsigned i; | |
200 | int r = 0; | |
201 | ||
202 | assert_cc(N_EARLY_MOUNT <= ELEMENTSOF(mount_table)); | |
203 | ||
204 | /* Do a minimal mount of /proc and friends to enable the most | |
205 | * basic stuff, such as SELinux */ | |
206 | for (i = 0; i < N_EARLY_MOUNT; i ++) { | |
207 | int j; | |
208 | ||
209 | j = mount_one(mount_table + i, false); | |
210 | if (r == 0) | |
211 | r = j; | |
212 | } | |
213 | ||
214 | return r; | |
215 | } | |
216 | ||
217 | int mount_cgroup_controllers(char ***join_controllers) { | |
663996b3 | 218 | _cleanup_set_free_free_ Set *controllers = NULL; |
60f067b4 | 219 | int r; |
663996b3 MS |
220 | |
221 | /* Mount all available cgroup controllers that are built into the kernel. */ | |
222 | ||
5eef597e | 223 | controllers = set_new(&string_hash_ops); |
663996b3 MS |
224 | if (!controllers) |
225 | return log_oom(); | |
226 | ||
e735f4d4 MP |
227 | r = cg_kernel_controllers(controllers); |
228 | if (r < 0) | |
229 | return log_error_errno(r, "Failed to enumerate cgroup controllers: %m"); | |
663996b3 MS |
230 | |
231 | for (;;) { | |
60f067b4 | 232 | _cleanup_free_ char *options = NULL, *controller = NULL, *where = NULL; |
663996b3 MS |
233 | MountPoint p = { |
234 | .what = "cgroup", | |
235 | .type = "cgroup", | |
236 | .flags = MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
237 | .mode = MNT_IN_CONTAINER, | |
238 | }; | |
239 | char ***k = NULL; | |
663996b3 MS |
240 | |
241 | controller = set_steal_first(controllers); | |
242 | if (!controller) | |
243 | break; | |
244 | ||
245 | if (join_controllers) | |
246 | for (k = join_controllers; *k; k++) | |
247 | if (strv_find(*k, controller)) | |
248 | break; | |
249 | ||
250 | if (k && *k) { | |
251 | char **i, **j; | |
252 | ||
253 | for (i = *k, j = *k; *i; i++) { | |
254 | ||
255 | if (!streq(*i, controller)) { | |
60f067b4 | 256 | _cleanup_free_ char *t; |
663996b3 MS |
257 | |
258 | t = set_remove(controllers, *i); | |
259 | if (!t) { | |
260 | free(*i); | |
261 | continue; | |
262 | } | |
263 | } | |
264 | ||
265 | *(j++) = *i; | |
266 | } | |
267 | ||
268 | *j = NULL; | |
269 | ||
270 | options = strv_join(*k, ","); | |
271 | if (!options) | |
272 | return log_oom(); | |
273 | } else { | |
274 | options = controller; | |
275 | controller = NULL; | |
276 | } | |
277 | ||
60f067b4 JS |
278 | where = strappend("/sys/fs/cgroup/", options); |
279 | if (!where) | |
280 | return log_oom(); | |
281 | ||
282 | p.where = where; | |
663996b3 MS |
283 | p.options = options; |
284 | ||
285 | r = mount_one(&p, true); | |
286 | if (r < 0) | |
287 | return r; | |
288 | ||
289 | if (r > 0 && k && *k) { | |
290 | char **i; | |
291 | ||
292 | for (i = *k; *i; i++) { | |
60f067b4 JS |
293 | _cleanup_free_ char *t = NULL; |
294 | ||
295 | t = strappend("/sys/fs/cgroup/", *i); | |
296 | if (!t) | |
297 | return log_oom(); | |
663996b3 MS |
298 | |
299 | r = symlink(options, t); | |
f47781d8 MP |
300 | if (r < 0 && errno != EEXIST) |
301 | return log_error_errno(errno, "Failed to create symlink %s: %m", t); | |
663996b3 MS |
302 | } |
303 | } | |
304 | } | |
305 | ||
60f067b4 JS |
306 | /* Now that we mounted everything, let's make the tmpfs the |
307 | * cgroup file systems are mounted into read-only. */ | |
e735f4d4 | 308 | (void) mount("tmpfs", "/sys/fs/cgroup", "tmpfs", MS_REMOUNT|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME|MS_RDONLY, "mode=755"); |
60f067b4 | 309 | |
663996b3 MS |
310 | return 0; |
311 | } | |
312 | ||
5eef597e | 313 | #if defined(HAVE_SELINUX) || defined(HAVE_SMACK) |
663996b3 MS |
314 | static int nftw_cb( |
315 | const char *fpath, | |
316 | const struct stat *sb, | |
317 | int tflag, | |
318 | struct FTW *ftwbuf) { | |
319 | ||
320 | /* No need to label /dev twice in a row... */ | |
321 | if (_unlikely_(ftwbuf->level == 0)) | |
322 | return FTW_CONTINUE; | |
323 | ||
324 | label_fix(fpath, false, false); | |
325 | ||
326 | /* /run/initramfs is static data and big, no need to | |
327 | * dynamically relabel its contents at boot... */ | |
328 | if (_unlikely_(ftwbuf->level == 1 && | |
329 | tflag == FTW_D && | |
330 | streq(fpath, "/run/initramfs"))) | |
331 | return FTW_SKIP_SUBTREE; | |
332 | ||
333 | return FTW_CONTINUE; | |
334 | }; | |
5eef597e | 335 | #endif |
663996b3 MS |
336 | |
337 | int mount_setup(bool loaded_policy) { | |
663996b3 | 338 | unsigned i; |
f47781d8 | 339 | int r = 0; |
663996b3 MS |
340 | |
341 | for (i = 0; i < ELEMENTSOF(mount_table); i ++) { | |
f47781d8 | 342 | int j; |
663996b3 | 343 | |
f47781d8 MP |
344 | j = mount_one(mount_table + i, loaded_policy); |
345 | if (r == 0) | |
346 | r = j; | |
663996b3 MS |
347 | } |
348 | ||
f47781d8 MP |
349 | if (r < 0) |
350 | return r; | |
351 | ||
5eef597e | 352 | #if defined(HAVE_SELINUX) || defined(HAVE_SMACK) |
663996b3 MS |
353 | /* Nodes in devtmpfs and /run need to be manually updated for |
354 | * the appropriate labels, after mounting. The other virtual | |
355 | * API file systems like /sys and /proc do not need that, they | |
356 | * use the same label for all their files. */ | |
357 | if (loaded_policy) { | |
358 | usec_t before_relabel, after_relabel; | |
359 | char timespan[FORMAT_TIMESPAN_MAX]; | |
360 | ||
361 | before_relabel = now(CLOCK_MONOTONIC); | |
362 | ||
363 | nftw("/dev", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL); | |
364 | nftw("/run", nftw_cb, 64, FTW_MOUNT|FTW_PHYS|FTW_ACTIONRETVAL); | |
365 | ||
663996b3 MS |
366 | after_relabel = now(CLOCK_MONOTONIC); |
367 | ||
368 | log_info("Relabelled /dev and /run in %s.", | |
369 | format_timespan(timespan, sizeof(timespan), after_relabel - before_relabel, 0)); | |
370 | } | |
5eef597e | 371 | #endif |
663996b3 MS |
372 | |
373 | /* Create a few default symlinks, which are normally created | |
374 | * by udevd, but some scripts might need them before we start | |
375 | * udevd. */ | |
e3bff60a | 376 | dev_setup(NULL, UID_INVALID, GID_INVALID); |
663996b3 MS |
377 | |
378 | /* Mark the root directory as shared in regards to mount | |
379 | * propagation. The kernel defaults to "private", but we think | |
380 | * it makes more sense to have a default of "shared" so that | |
381 | * nspawn and the container tools work out of the box. If | |
382 | * specific setups need other settings they can reset the | |
383 | * propagation mode to private if needed. */ | |
384 | if (detect_container(NULL) <= 0) | |
385 | if (mount(NULL, "/", NULL, MS_REC|MS_SHARED, NULL) < 0) | |
f47781d8 | 386 | log_warning_errno(errno, "Failed to set up the root directory for shared mount propagation: %m"); |
663996b3 MS |
387 | |
388 | /* Create a few directories we always want around, Note that | |
389 | * sd_booted() checks for /run/systemd/system, so this mkdir | |
390 | * really needs to stay for good, otherwise software that | |
391 | * copied sd-daemon.c into their sources will misdetect | |
392 | * systemd. */ | |
393 | mkdir_label("/run/systemd", 0755); | |
394 | mkdir_label("/run/systemd/system", 0755); | |
395 | mkdir_label("/run/systemd/inaccessible", 0000); | |
396 | ||
397 | return 0; | |
398 | } |