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d6c9574f | 1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
15ae422b 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 | |
15ae422b 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. |
15ae422b | 17 | |
5430f7f2 | 18 | You should have received a copy of the GNU Lesser General Public License |
15ae422b LP |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. |
20 | ***/ | |
21 | ||
22 | #include <errno.h> | |
23 | #include <sys/mount.h> | |
24 | #include <string.h> | |
25 | #include <stdio.h> | |
26 | #include <unistd.h> | |
27 | #include <sys/stat.h> | |
15ae422b | 28 | #include <sched.h> |
25e870b5 | 29 | #include <linux/fs.h> |
15ae422b LP |
30 | |
31 | #include "strv.h" | |
32 | #include "util.h" | |
9eb977db | 33 | #include "path-util.h" |
15ae422b | 34 | #include "missing.h" |
613b411c | 35 | #include "loopback-setup.h" |
7f112f50 | 36 | #include "dev-setup.h" |
d7b8eec7 LP |
37 | #include "selinux-util.h" |
38 | #include "namespace.h" | |
ee818b89 | 39 | #include "mkdir.h" |
15ae422b | 40 | |
c17ec25e | 41 | typedef enum MountMode { |
15ae422b LP |
42 | /* This is ordered by priority! */ |
43 | INACCESSIBLE, | |
44 | READONLY, | |
ac0930c8 LP |
45 | PRIVATE_TMP, |
46 | PRIVATE_VAR_TMP, | |
7f112f50 | 47 | PRIVATE_DEV, |
a610cc4f | 48 | PRIVATE_BUS_ENDPOINT, |
15ae422b | 49 | READWRITE |
c17ec25e | 50 | } MountMode; |
15ae422b | 51 | |
c17ec25e | 52 | typedef struct BindMount { |
15ae422b | 53 | const char *path; |
c17ec25e | 54 | MountMode mode; |
ac0930c8 | 55 | bool done; |
ea92ae33 | 56 | bool ignore; |
c17ec25e | 57 | } BindMount; |
15ae422b | 58 | |
c17ec25e | 59 | static int append_mounts(BindMount **p, char **strv, MountMode mode) { |
15ae422b LP |
60 | char **i; |
61 | ||
613b411c LP |
62 | assert(p); |
63 | ||
15ae422b LP |
64 | STRV_FOREACH(i, strv) { |
65 | ||
ea92ae33 | 66 | (*p)->ignore = false; |
002b2268 | 67 | (*p)->done = false; |
ea92ae33 | 68 | |
94828d2d | 69 | if ((mode == INACCESSIBLE || mode == READONLY || mode == READWRITE) && (*i)[0] == '-') { |
ea92ae33 MW |
70 | (*p)->ignore = true; |
71 | (*i)++; | |
72 | } | |
73 | ||
15ae422b LP |
74 | if (!path_is_absolute(*i)) |
75 | return -EINVAL; | |
76 | ||
77 | (*p)->path = *i; | |
78 | (*p)->mode = mode; | |
79 | (*p)++; | |
80 | } | |
81 | ||
82 | return 0; | |
83 | } | |
84 | ||
c17ec25e MS |
85 | static int mount_path_compare(const void *a, const void *b) { |
86 | const BindMount *p = a, *q = b; | |
a0827e2b | 87 | int d; |
15ae422b | 88 | |
a0827e2b | 89 | d = path_compare(p->path, q->path); |
15ae422b | 90 | |
5a8af538 | 91 | if (d == 0) { |
15ae422b LP |
92 | /* If the paths are equal, check the mode */ |
93 | if (p->mode < q->mode) | |
94 | return -1; | |
95 | ||
96 | if (p->mode > q->mode) | |
97 | return 1; | |
98 | ||
99 | return 0; | |
100 | } | |
101 | ||
102 | /* If the paths are not equal, then order prefixes first */ | |
a0827e2b | 103 | return d; |
15ae422b LP |
104 | } |
105 | ||
c17ec25e MS |
106 | static void drop_duplicates(BindMount *m, unsigned *n) { |
107 | BindMount *f, *t, *previous; | |
15ae422b | 108 | |
c17ec25e | 109 | assert(m); |
15ae422b | 110 | assert(n); |
15ae422b | 111 | |
c17ec25e | 112 | for (f = m, t = m, previous = NULL; f < m+*n; f++) { |
15ae422b | 113 | |
ac0930c8 | 114 | /* The first one wins */ |
15ae422b LP |
115 | if (previous && path_equal(f->path, previous->path)) |
116 | continue; | |
117 | ||
e2d7c1a0 | 118 | *t = *f; |
15ae422b | 119 | |
15ae422b LP |
120 | previous = t; |
121 | ||
122 | t++; | |
123 | } | |
124 | ||
c17ec25e | 125 | *n = t - m; |
15ae422b LP |
126 | } |
127 | ||
7f112f50 LP |
128 | static int mount_dev(BindMount *m) { |
129 | static const char devnodes[] = | |
130 | "/dev/null\0" | |
131 | "/dev/zero\0" | |
132 | "/dev/full\0" | |
133 | "/dev/random\0" | |
134 | "/dev/urandom\0" | |
135 | "/dev/tty\0"; | |
136 | ||
2b85f4e1 | 137 | char temporary_mount[] = "/tmp/namespace-dev-XXXXXX"; |
63cc4c31 | 138 | const char *d, *dev = NULL, *devpts = NULL, *devshm = NULL, *devhugepages = NULL, *devmqueue = NULL, *devlog = NULL, *devptmx = NULL; |
7f112f50 LP |
139 | _cleanup_umask_ mode_t u; |
140 | int r; | |
141 | ||
142 | assert(m); | |
143 | ||
144 | u = umask(0000); | |
145 | ||
2b85f4e1 LP |
146 | if (!mkdtemp(temporary_mount)) |
147 | return -errno; | |
148 | ||
63c372cb | 149 | dev = strjoina(temporary_mount, "/dev"); |
dc751688 | 150 | (void) mkdir(dev, 0755); |
2b85f4e1 LP |
151 | if (mount("tmpfs", dev, "tmpfs", MS_NOSUID|MS_STRICTATIME, "mode=755") < 0) { |
152 | r = -errno; | |
153 | goto fail; | |
154 | } | |
155 | ||
63c372cb | 156 | devpts = strjoina(temporary_mount, "/dev/pts"); |
dc751688 | 157 | (void) mkdir(devpts, 0755); |
2b85f4e1 LP |
158 | if (mount("/dev/pts", devpts, NULL, MS_BIND, NULL) < 0) { |
159 | r = -errno; | |
160 | goto fail; | |
161 | } | |
162 | ||
63c372cb | 163 | devptmx = strjoina(temporary_mount, "/dev/ptmx"); |
3164e3cb ZJS |
164 | if (symlink("pts/ptmx", devptmx) < 0) { |
165 | r = -errno; | |
166 | goto fail; | |
167 | } | |
e06b6479 | 168 | |
63c372cb | 169 | devshm = strjoina(temporary_mount, "/dev/shm"); |
dc751688 | 170 | (void) mkdir(devshm, 01777); |
2b85f4e1 LP |
171 | r = mount("/dev/shm", devshm, NULL, MS_BIND, NULL); |
172 | if (r < 0) { | |
173 | r = -errno; | |
174 | goto fail; | |
175 | } | |
176 | ||
63c372cb | 177 | devmqueue = strjoina(temporary_mount, "/dev/mqueue"); |
dc751688 | 178 | (void) mkdir(devmqueue, 0755); |
3164e3cb | 179 | (void) mount("/dev/mqueue", devmqueue, NULL, MS_BIND, NULL); |
2b85f4e1 | 180 | |
63c372cb | 181 | devhugepages = strjoina(temporary_mount, "/dev/hugepages"); |
dc751688 | 182 | (void) mkdir(devhugepages, 0755); |
3164e3cb | 183 | (void) mount("/dev/hugepages", devhugepages, NULL, MS_BIND, NULL); |
2b85f4e1 | 184 | |
63c372cb | 185 | devlog = strjoina(temporary_mount, "/dev/log"); |
3164e3cb | 186 | (void) symlink("/run/systemd/journal/dev-log", devlog); |
82d25240 | 187 | |
7f112f50 | 188 | NULSTR_FOREACH(d, devnodes) { |
2b85f4e1 LP |
189 | _cleanup_free_ char *dn = NULL; |
190 | struct stat st; | |
191 | ||
192 | r = stat(d, &st); | |
7f112f50 | 193 | if (r < 0) { |
2b85f4e1 LP |
194 | |
195 | if (errno == ENOENT) | |
196 | continue; | |
197 | ||
198 | r = -errno; | |
199 | goto fail; | |
7f112f50 LP |
200 | } |
201 | ||
2b85f4e1 LP |
202 | if (!S_ISBLK(st.st_mode) && |
203 | !S_ISCHR(st.st_mode)) { | |
204 | r = -EINVAL; | |
205 | goto fail; | |
206 | } | |
207 | ||
208 | if (st.st_rdev == 0) | |
209 | continue; | |
210 | ||
211 | dn = strappend(temporary_mount, d); | |
212 | if (!dn) { | |
213 | r = -ENOMEM; | |
214 | goto fail; | |
215 | } | |
216 | ||
ecabcf8b | 217 | mac_selinux_create_file_prepare(d, st.st_mode); |
2b85f4e1 | 218 | r = mknod(dn, st.st_mode, st.st_rdev); |
ecabcf8b | 219 | mac_selinux_create_file_clear(); |
dd078a1e | 220 | |
2b85f4e1 LP |
221 | if (r < 0) { |
222 | r = -errno; | |
223 | goto fail; | |
224 | } | |
7f112f50 LP |
225 | } |
226 | ||
03cfe0d5 | 227 | dev_setup(temporary_mount, UID_INVALID, GID_INVALID); |
7f112f50 | 228 | |
ee818b89 AC |
229 | /* Create the /dev directory if missing. It is more likely to be |
230 | * missing when the service is started with RootDirectory. This is | |
231 | * consistent with mount units creating the mount points when missing. | |
232 | */ | |
233 | (void) mkdir_p_label(m->path, 0755); | |
234 | ||
235 | if (mount(dev, m->path, NULL, MS_MOVE, NULL) < 0) { | |
2b85f4e1 LP |
236 | r = -errno; |
237 | goto fail; | |
238 | } | |
7f112f50 | 239 | |
2b85f4e1 LP |
240 | rmdir(dev); |
241 | rmdir(temporary_mount); | |
7f112f50 | 242 | |
2b85f4e1 | 243 | return 0; |
7f112f50 | 244 | |
2b85f4e1 LP |
245 | fail: |
246 | if (devpts) | |
247 | umount(devpts); | |
7f112f50 | 248 | |
2b85f4e1 LP |
249 | if (devshm) |
250 | umount(devshm); | |
7f112f50 | 251 | |
2b85f4e1 LP |
252 | if (devhugepages) |
253 | umount(devhugepages); | |
7f112f50 | 254 | |
2b85f4e1 LP |
255 | if (devmqueue) |
256 | umount(devmqueue); | |
7f112f50 | 257 | |
d267c5aa ZJS |
258 | umount(dev); |
259 | rmdir(dev); | |
2b85f4e1 | 260 | rmdir(temporary_mount); |
7f112f50 | 261 | |
2b85f4e1 | 262 | return r; |
7f112f50 LP |
263 | } |
264 | ||
a610cc4f DM |
265 | static int mount_kdbus(BindMount *m) { |
266 | ||
267 | char temporary_mount[] = "/tmp/kdbus-dev-XXXXXX"; | |
268 | _cleanup_free_ char *basepath = NULL; | |
269 | _cleanup_umask_ mode_t u; | |
120d578e | 270 | char *busnode = NULL, *root; |
a610cc4f DM |
271 | struct stat st; |
272 | int r; | |
273 | ||
274 | assert(m); | |
275 | ||
276 | u = umask(0000); | |
277 | ||
4a62c710 MS |
278 | if (!mkdtemp(temporary_mount)) |
279 | return log_error_errno(errno, "Failed create temp dir: %m"); | |
a610cc4f | 280 | |
63c372cb | 281 | root = strjoina(temporary_mount, "/kdbus"); |
dc751688 | 282 | (void) mkdir(root, 0755); |
a610cc4f DM |
283 | if (mount("tmpfs", root, "tmpfs", MS_NOSUID|MS_STRICTATIME, "mode=777") < 0) { |
284 | r = -errno; | |
285 | goto fail; | |
286 | } | |
287 | ||
288 | /* create a new /dev/null dev node copy so we have some fodder to | |
289 | * bind-mount the custom endpoint over. */ | |
290 | if (stat("/dev/null", &st) < 0) { | |
56f64d95 | 291 | log_error_errno(errno, "Failed to stat /dev/null: %m"); |
a610cc4f DM |
292 | r = -errno; |
293 | goto fail; | |
294 | } | |
295 | ||
63c372cb | 296 | busnode = strjoina(root, "/bus"); |
a610cc4f | 297 | if (mknod(busnode, (st.st_mode & ~07777) | 0600, st.st_rdev) < 0) { |
56f64d95 | 298 | log_error_errno(errno, "mknod() for %s failed: %m", busnode); |
a610cc4f DM |
299 | r = -errno; |
300 | goto fail; | |
301 | } | |
302 | ||
4543768d | 303 | r = mount(m->path, busnode, NULL, MS_BIND, NULL); |
a610cc4f | 304 | if (r < 0) { |
56f64d95 | 305 | log_error_errno(errno, "bind mount of %s failed: %m", m->path); |
a610cc4f DM |
306 | r = -errno; |
307 | goto fail; | |
308 | } | |
309 | ||
310 | basepath = dirname_malloc(m->path); | |
311 | if (!basepath) { | |
312 | r = -ENOMEM; | |
313 | goto fail; | |
314 | } | |
315 | ||
316 | if (mount(root, basepath, NULL, MS_MOVE, NULL) < 0) { | |
56f64d95 | 317 | log_error_errno(errno, "bind mount of %s failed: %m", basepath); |
a610cc4f DM |
318 | r = -errno; |
319 | goto fail; | |
320 | } | |
321 | ||
322 | rmdir(temporary_mount); | |
323 | return 0; | |
324 | ||
325 | fail: | |
326 | if (busnode) { | |
327 | umount(busnode); | |
328 | unlink(busnode); | |
329 | } | |
330 | ||
1775f1eb ZJS |
331 | umount(root); |
332 | rmdir(root); | |
a610cc4f DM |
333 | rmdir(temporary_mount); |
334 | ||
335 | return r; | |
336 | } | |
337 | ||
ac0930c8 | 338 | static int apply_mount( |
c17ec25e | 339 | BindMount *m, |
ac0930c8 | 340 | const char *tmp_dir, |
c17ec25e | 341 | const char *var_tmp_dir) { |
ac0930c8 | 342 | |
15ae422b | 343 | const char *what; |
15ae422b | 344 | int r; |
15ae422b | 345 | |
c17ec25e | 346 | assert(m); |
15ae422b | 347 | |
c17ec25e | 348 | switch (m->mode) { |
15ae422b LP |
349 | |
350 | case INACCESSIBLE: | |
6d313367 LP |
351 | |
352 | /* First, get rid of everything that is below if there | |
353 | * is anything... Then, overmount it with an | |
354 | * inaccessible directory. */ | |
355 | umount_recursive(m->path, 0); | |
356 | ||
c17ec25e | 357 | what = "/run/systemd/inaccessible"; |
15ae422b LP |
358 | break; |
359 | ||
360 | case READONLY: | |
15ae422b | 361 | case READWRITE: |
d6797c92 LP |
362 | /* Nothing to mount here, we just later toggle the |
363 | * MS_RDONLY bit for the mount point */ | |
364 | return 0; | |
15ae422b | 365 | |
ac0930c8 LP |
366 | case PRIVATE_TMP: |
367 | what = tmp_dir; | |
368 | break; | |
369 | ||
370 | case PRIVATE_VAR_TMP: | |
371 | what = var_tmp_dir; | |
15ae422b | 372 | break; |
e364ad06 | 373 | |
d6797c92 LP |
374 | case PRIVATE_DEV: |
375 | return mount_dev(m); | |
376 | ||
a610cc4f DM |
377 | case PRIVATE_BUS_ENDPOINT: |
378 | return mount_kdbus(m); | |
379 | ||
e364ad06 LP |
380 | default: |
381 | assert_not_reached("Unknown mode"); | |
15ae422b LP |
382 | } |
383 | ||
ac0930c8 | 384 | assert(what); |
15ae422b | 385 | |
c17ec25e | 386 | r = mount(what, m->path, NULL, MS_BIND|MS_REC, NULL); |
ac0930c8 | 387 | if (r >= 0) |
c17ec25e | 388 | log_debug("Successfully mounted %s to %s", what, m->path); |
ea92ae33 | 389 | else if (m->ignore && errno == ENOENT) |
d6797c92 | 390 | return 0; |
15ae422b | 391 | |
ac0930c8 LP |
392 | return r; |
393 | } | |
15ae422b | 394 | |
c17ec25e | 395 | static int make_read_only(BindMount *m) { |
ac0930c8 | 396 | int r; |
15ae422b | 397 | |
c17ec25e | 398 | assert(m); |
ac0930c8 | 399 | |
d6797c92 LP |
400 | if (IN_SET(m->mode, INACCESSIBLE, READONLY)) |
401 | r = bind_remount_recursive(m->path, true); | |
664064d6 | 402 | else if (IN_SET(m->mode, READWRITE, PRIVATE_TMP, PRIVATE_VAR_TMP, PRIVATE_DEV)) |
d6797c92 LP |
403 | r = bind_remount_recursive(m->path, false); |
404 | else | |
405 | r = 0; | |
ac0930c8 | 406 | |
d6797c92 LP |
407 | if (m->ignore && r == -ENOENT) |
408 | return 0; | |
ac0930c8 | 409 | |
d6797c92 | 410 | return r; |
15ae422b LP |
411 | } |
412 | ||
613b411c | 413 | int setup_namespace( |
ee818b89 | 414 | const char* root_directory, |
613b411c LP |
415 | char** read_write_dirs, |
416 | char** read_only_dirs, | |
417 | char** inaccessible_dirs, | |
a004cb4c LP |
418 | const char* tmp_dir, |
419 | const char* var_tmp_dir, | |
420 | const char* bus_endpoint_path, | |
7f112f50 | 421 | bool private_dev, |
1b8689f9 LP |
422 | ProtectHome protect_home, |
423 | ProtectSystem protect_system, | |
e6547662 | 424 | unsigned long mount_flags) { |
15ae422b | 425 | |
7ff7394d | 426 | BindMount *m, *mounts = NULL; |
613b411c | 427 | unsigned n; |
c17ec25e | 428 | int r = 0; |
15ae422b | 429 | |
613b411c | 430 | if (mount_flags == 0) |
c17ec25e | 431 | mount_flags = MS_SHARED; |
ac0930c8 | 432 | |
d5a3f0ea ZJS |
433 | if (unshare(CLONE_NEWNS) < 0) |
434 | return -errno; | |
15ae422b | 435 | |
a610cc4f | 436 | n = !!tmp_dir + !!var_tmp_dir + !!bus_endpoint_path + |
613b411c LP |
437 | strv_length(read_write_dirs) + |
438 | strv_length(read_only_dirs) + | |
7f112f50 | 439 | strv_length(inaccessible_dirs) + |
417116f2 | 440 | private_dev + |
c8835999 | 441 | (protect_home != PROTECT_HOME_NO ? 3 : 0) + |
051be1f7 | 442 | (protect_system != PROTECT_SYSTEM_NO ? 2 : 0) + |
1b8689f9 | 443 | (protect_system == PROTECT_SYSTEM_FULL ? 1 : 0); |
613b411c LP |
444 | |
445 | if (n > 0) { | |
002b2268 | 446 | m = mounts = (BindMount *) alloca0(n * sizeof(BindMount)); |
613b411c LP |
447 | r = append_mounts(&m, read_write_dirs, READWRITE); |
448 | if (r < 0) | |
449 | return r; | |
450 | ||
451 | r = append_mounts(&m, read_only_dirs, READONLY); | |
452 | if (r < 0) | |
453 | return r; | |
454 | ||
455 | r = append_mounts(&m, inaccessible_dirs, INACCESSIBLE); | |
456 | if (r < 0) | |
7ff7394d ZJS |
457 | return r; |
458 | ||
613b411c | 459 | if (tmp_dir) { |
ee818b89 | 460 | m->path = prefix_roota(root_directory, "/tmp"); |
7ff7394d ZJS |
461 | m->mode = PRIVATE_TMP; |
462 | m++; | |
613b411c | 463 | } |
7ff7394d | 464 | |
613b411c | 465 | if (var_tmp_dir) { |
ee818b89 | 466 | m->path = prefix_roota(root_directory, "/var/tmp"); |
7ff7394d ZJS |
467 | m->mode = PRIVATE_VAR_TMP; |
468 | m++; | |
469 | } | |
ac0930c8 | 470 | |
7f112f50 | 471 | if (private_dev) { |
ee818b89 | 472 | m->path = prefix_roota(root_directory, "/dev"); |
7f112f50 LP |
473 | m->mode = PRIVATE_DEV; |
474 | m++; | |
475 | } | |
476 | ||
a610cc4f | 477 | if (bus_endpoint_path) { |
ee818b89 | 478 | m->path = prefix_roota(root_directory, bus_endpoint_path); |
a610cc4f DM |
479 | m->mode = PRIVATE_BUS_ENDPOINT; |
480 | m++; | |
481 | } | |
482 | ||
1b8689f9 | 483 | if (protect_home != PROTECT_HOME_NO) { |
ee818b89 AC |
484 | const char *home_dir, *run_user_dir, *root_dir; |
485 | ||
486 | home_dir = prefix_roota(root_directory, "/home"); | |
487 | home_dir = strjoina("-", home_dir); | |
488 | run_user_dir = prefix_roota(root_directory, "/run/user"); | |
489 | run_user_dir = strjoina("-", run_user_dir); | |
490 | root_dir = prefix_roota(root_directory, "/root"); | |
491 | root_dir = strjoina("-", root_dir); | |
492 | ||
493 | r = append_mounts(&m, STRV_MAKE(home_dir, run_user_dir, root_dir), | |
494 | protect_home == PROTECT_HOME_READ_ONLY ? READONLY : INACCESSIBLE); | |
417116f2 LP |
495 | if (r < 0) |
496 | return r; | |
497 | } | |
498 | ||
1b8689f9 | 499 | if (protect_system != PROTECT_SYSTEM_NO) { |
ee818b89 AC |
500 | const char *usr_dir, *boot_dir, *etc_dir; |
501 | ||
d38e01dc | 502 | usr_dir = prefix_roota(root_directory, "/usr"); |
ee818b89 AC |
503 | boot_dir = prefix_roota(root_directory, "/boot"); |
504 | boot_dir = strjoina("-", boot_dir); | |
505 | etc_dir = prefix_roota(root_directory, "/etc"); | |
506 | ||
507 | r = append_mounts(&m, protect_system == PROTECT_SYSTEM_FULL | |
508 | ? STRV_MAKE(usr_dir, boot_dir, etc_dir) | |
509 | : STRV_MAKE(usr_dir, boot_dir), READONLY); | |
417116f2 LP |
510 | if (r < 0) |
511 | return r; | |
512 | } | |
513 | ||
7ff7394d | 514 | assert(mounts + n == m); |
ac0930c8 | 515 | |
7ff7394d ZJS |
516 | qsort(mounts, n, sizeof(BindMount), mount_path_compare); |
517 | drop_duplicates(mounts, &n); | |
15ae422b LP |
518 | } |
519 | ||
ee818b89 | 520 | if (n > 0 || root_directory) { |
c2c13f2d LP |
521 | /* Remount / as SLAVE so that nothing now mounted in the namespace |
522 | shows up in the parent */ | |
523 | if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) | |
524 | return -errno; | |
ee818b89 AC |
525 | } |
526 | ||
527 | if (root_directory) { | |
528 | /* Turn directory into bind mount */ | |
529 | if (mount(root_directory, root_directory, NULL, MS_BIND|MS_REC, NULL) < 0) | |
530 | return -errno; | |
531 | } | |
c2c13f2d | 532 | |
ee818b89 | 533 | if (n > 0) { |
c2c13f2d LP |
534 | for (m = mounts; m < mounts + n; ++m) { |
535 | r = apply_mount(m, tmp_dir, var_tmp_dir); | |
536 | if (r < 0) | |
537 | goto fail; | |
538 | } | |
15ae422b | 539 | |
c2c13f2d LP |
540 | for (m = mounts; m < mounts + n; ++m) { |
541 | r = make_read_only(m); | |
542 | if (r < 0) | |
543 | goto fail; | |
544 | } | |
15ae422b LP |
545 | } |
546 | ||
ee818b89 AC |
547 | if (root_directory) { |
548 | /* MS_MOVE does not work on MS_SHARED so the remount MS_SHARED will be done later */ | |
549 | r = mount_move_root(root_directory); | |
550 | ||
551 | /* at this point, we cannot rollback */ | |
552 | if (r < 0) | |
553 | return r; | |
554 | } | |
555 | ||
c2c13f2d LP |
556 | /* Remount / as the desired mode. Not that this will not |
557 | * reestablish propagation from our side to the host, since | |
558 | * what's disconnected is disconnected. */ | |
c17ec25e | 559 | if (mount(NULL, "/", NULL, mount_flags | MS_REC, NULL) < 0) { |
ee818b89 AC |
560 | /* at this point, we cannot rollback */ |
561 | return -errno; | |
15ae422b LP |
562 | } |
563 | ||
15ae422b LP |
564 | return 0; |
565 | ||
613b411c | 566 | fail: |
c2c13f2d LP |
567 | if (n > 0) { |
568 | for (m = mounts; m < mounts + n; ++m) | |
569 | if (m->done) | |
42b1b990 | 570 | (void) umount2(m->path, MNT_DETACH); |
c2c13f2d | 571 | } |
613b411c LP |
572 | |
573 | return r; | |
574 | } | |
575 | ||
576 | static int setup_one_tmp_dir(const char *id, const char *prefix, char **path) { | |
577 | _cleanup_free_ char *x = NULL; | |
6b46ea73 LP |
578 | char bid[SD_ID128_STRING_MAX]; |
579 | sd_id128_t boot_id; | |
580 | int r; | |
613b411c LP |
581 | |
582 | assert(id); | |
583 | assert(prefix); | |
584 | assert(path); | |
585 | ||
6b46ea73 LP |
586 | /* We include the boot id in the directory so that after a |
587 | * reboot we can easily identify obsolete directories. */ | |
588 | ||
589 | r = sd_id128_get_boot(&boot_id); | |
590 | if (r < 0) | |
591 | return r; | |
592 | ||
593 | x = strjoin(prefix, "/systemd-private-", sd_id128_to_string(boot_id, bid), "-", id, "-XXXXXX", NULL); | |
613b411c LP |
594 | if (!x) |
595 | return -ENOMEM; | |
596 | ||
597 | RUN_WITH_UMASK(0077) | |
598 | if (!mkdtemp(x)) | |
599 | return -errno; | |
600 | ||
601 | RUN_WITH_UMASK(0000) { | |
602 | char *y; | |
603 | ||
63c372cb | 604 | y = strjoina(x, "/tmp"); |
613b411c LP |
605 | |
606 | if (mkdir(y, 0777 | S_ISVTX) < 0) | |
607 | return -errno; | |
c17ec25e | 608 | } |
15ae422b | 609 | |
613b411c LP |
610 | *path = x; |
611 | x = NULL; | |
612 | ||
613 | return 0; | |
614 | } | |
615 | ||
616 | int setup_tmp_dirs(const char *id, char **tmp_dir, char **var_tmp_dir) { | |
617 | char *a, *b; | |
618 | int r; | |
619 | ||
620 | assert(id); | |
621 | assert(tmp_dir); | |
622 | assert(var_tmp_dir); | |
623 | ||
624 | r = setup_one_tmp_dir(id, "/tmp", &a); | |
625 | if (r < 0) | |
626 | return r; | |
627 | ||
628 | r = setup_one_tmp_dir(id, "/var/tmp", &b); | |
629 | if (r < 0) { | |
630 | char *t; | |
631 | ||
63c372cb | 632 | t = strjoina(a, "/tmp"); |
613b411c LP |
633 | rmdir(t); |
634 | rmdir(a); | |
635 | ||
636 | free(a); | |
637 | return r; | |
638 | } | |
639 | ||
640 | *tmp_dir = a; | |
641 | *var_tmp_dir = b; | |
642 | ||
643 | return 0; | |
644 | } | |
645 | ||
646 | int setup_netns(int netns_storage_socket[2]) { | |
647 | _cleanup_close_ int netns = -1; | |
648 | union { | |
649 | struct cmsghdr cmsghdr; | |
650 | uint8_t buf[CMSG_SPACE(sizeof(int))]; | |
651 | } control = {}; | |
652 | struct msghdr mh = { | |
653 | .msg_control = &control, | |
654 | .msg_controllen = sizeof(control), | |
655 | }; | |
656 | struct cmsghdr *cmsg; | |
657 | int r; | |
658 | ||
659 | assert(netns_storage_socket); | |
660 | assert(netns_storage_socket[0] >= 0); | |
661 | assert(netns_storage_socket[1] >= 0); | |
662 | ||
663 | /* We use the passed socketpair as a storage buffer for our | |
76cd584b LP |
664 | * namespace reference fd. Whatever process runs this first |
665 | * shall create a new namespace, all others should just join | |
666 | * it. To serialize that we use a file lock on the socket | |
667 | * pair. | |
613b411c LP |
668 | * |
669 | * It's a bit crazy, but hey, works great! */ | |
670 | ||
671 | if (lockf(netns_storage_socket[0], F_LOCK, 0) < 0) | |
672 | return -errno; | |
673 | ||
674 | if (recvmsg(netns_storage_socket[0], &mh, MSG_DONTWAIT|MSG_CMSG_CLOEXEC) < 0) { | |
675 | if (errno != EAGAIN) { | |
676 | r = -errno; | |
677 | goto fail; | |
678 | } | |
679 | ||
680 | /* Nothing stored yet, so let's create a new namespace */ | |
681 | ||
682 | if (unshare(CLONE_NEWNET) < 0) { | |
683 | r = -errno; | |
684 | goto fail; | |
685 | } | |
686 | ||
687 | loopback_setup(); | |
688 | ||
689 | netns = open("/proc/self/ns/net", O_RDONLY|O_CLOEXEC|O_NOCTTY); | |
690 | if (netns < 0) { | |
691 | r = -errno; | |
692 | goto fail; | |
693 | } | |
694 | ||
695 | r = 1; | |
696 | } else { | |
697 | /* Yay, found something, so let's join the namespace */ | |
698 | ||
2a1288ff | 699 | CMSG_FOREACH(cmsg, &mh) |
613b411c LP |
700 | if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) { |
701 | assert(cmsg->cmsg_len == CMSG_LEN(sizeof(int))); | |
702 | netns = *(int*) CMSG_DATA(cmsg); | |
703 | } | |
613b411c LP |
704 | |
705 | if (setns(netns, CLONE_NEWNET) < 0) { | |
706 | r = -errno; | |
707 | goto fail; | |
708 | } | |
709 | ||
710 | r = 0; | |
711 | } | |
712 | ||
713 | cmsg = CMSG_FIRSTHDR(&mh); | |
714 | cmsg->cmsg_level = SOL_SOCKET; | |
715 | cmsg->cmsg_type = SCM_RIGHTS; | |
716 | cmsg->cmsg_len = CMSG_LEN(sizeof(int)); | |
717 | memcpy(CMSG_DATA(cmsg), &netns, sizeof(int)); | |
718 | mh.msg_controllen = cmsg->cmsg_len; | |
719 | ||
720 | if (sendmsg(netns_storage_socket[1], &mh, MSG_DONTWAIT|MSG_NOSIGNAL) < 0) { | |
721 | r = -errno; | |
722 | goto fail; | |
723 | } | |
724 | ||
725 | fail: | |
726 | lockf(netns_storage_socket[0], F_ULOCK, 0); | |
727 | ||
15ae422b LP |
728 | return r; |
729 | } | |
417116f2 | 730 | |
1b8689f9 LP |
731 | static const char *const protect_home_table[_PROTECT_HOME_MAX] = { |
732 | [PROTECT_HOME_NO] = "no", | |
733 | [PROTECT_HOME_YES] = "yes", | |
734 | [PROTECT_HOME_READ_ONLY] = "read-only", | |
417116f2 LP |
735 | }; |
736 | ||
1b8689f9 LP |
737 | DEFINE_STRING_TABLE_LOOKUP(protect_home, ProtectHome); |
738 | ||
739 | static const char *const protect_system_table[_PROTECT_SYSTEM_MAX] = { | |
740 | [PROTECT_SYSTEM_NO] = "no", | |
741 | [PROTECT_SYSTEM_YES] = "yes", | |
742 | [PROTECT_SYSTEM_FULL] = "full", | |
743 | }; | |
744 | ||
745 | DEFINE_STRING_TABLE_LOOKUP(protect_system, ProtectSystem); |