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db9ecf05 | 1 | /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
e83bebef | 2 | |
4f5dd394 | 3 | #include <sys/mount.h> |
07630cea | 4 | #include <linux/magic.h> |
e83bebef | 5 | |
b5efdb8a | 6 | #include "alloc-util.h" |
f4351959 | 7 | #include "chase-symlinks.h" |
4f5dd394 | 8 | #include "escape.h" |
0996ef00 | 9 | #include "fd-util.h" |
ca78ad1d | 10 | #include "format-util.h" |
f4f15635 | 11 | #include "fs-util.h" |
e83bebef | 12 | #include "label.h" |
4f5dd394 | 13 | #include "mkdir.h" |
4349cd7c | 14 | #include "mount-util.h" |
049af8ad | 15 | #include "mountpoint-util.h" |
6bedfcbb LP |
16 | #include "nspawn-mount.h" |
17 | #include "parse-util.h" | |
4f5dd394 LP |
18 | #include "path-util.h" |
19 | #include "rm-rf.h" | |
e83bebef | 20 | #include "set.h" |
760877e9 | 21 | #include "sort-util.h" |
8fcde012 | 22 | #include "stat-util.h" |
07630cea | 23 | #include "string-util.h" |
4f5dd394 | 24 | #include "strv.h" |
e4de7287 | 25 | #include "tmpfile-util.h" |
ee104e11 | 26 | #include "user-util.h" |
e83bebef | 27 | |
88614c8a | 28 | CustomMount* custom_mount_add(CustomMount **l, size_t *n, CustomMountType t) { |
e83bebef LP |
29 | CustomMount *c, *ret; |
30 | ||
31 | assert(l); | |
32 | assert(n); | |
33 | assert(t >= 0); | |
34 | assert(t < _CUSTOM_MOUNT_TYPE_MAX); | |
35 | ||
aa484f35 | 36 | c = reallocarray(*l, *n + 1, sizeof(CustomMount)); |
e83bebef LP |
37 | if (!c) |
38 | return NULL; | |
39 | ||
40 | *l = c; | |
41 | ret = *l + *n; | |
42 | (*n)++; | |
43 | ||
511a8cfe LP |
44 | *ret = (CustomMount) { |
45 | .type = t | |
46 | }; | |
e83bebef LP |
47 | |
48 | return ret; | |
49 | } | |
50 | ||
88614c8a | 51 | void custom_mount_free_all(CustomMount *l, size_t n) { |
d2b99ed7 | 52 | for (size_t i = 0; i < n; i++) { |
e83bebef LP |
53 | CustomMount *m = l + i; |
54 | ||
55 | free(m->source); | |
56 | free(m->destination); | |
57 | free(m->options); | |
58 | ||
59 | if (m->work_dir) { | |
60 | (void) rm_rf(m->work_dir, REMOVE_ROOT|REMOVE_PHYSICAL); | |
61 | free(m->work_dir); | |
62 | } | |
63 | ||
c7a4890c LP |
64 | if (m->rm_rf_tmpdir) { |
65 | (void) rm_rf(m->rm_rf_tmpdir, REMOVE_ROOT|REMOVE_PHYSICAL); | |
66 | free(m->rm_rf_tmpdir); | |
67 | } | |
68 | ||
e83bebef | 69 | strv_free(m->lower); |
de40a303 | 70 | free(m->type_argument); |
e83bebef LP |
71 | } |
72 | ||
73 | free(l); | |
74 | } | |
75 | ||
93bab288 | 76 | static int custom_mount_compare(const CustomMount *a, const CustomMount *b) { |
e83bebef LP |
77 | int r; |
78 | ||
93bab288 | 79 | r = path_compare(a->destination, b->destination); |
e83bebef LP |
80 | if (r != 0) |
81 | return r; | |
82 | ||
93bab288 | 83 | return CMP(a->type, b->type); |
e83bebef LP |
84 | } |
85 | ||
86c0dd4a LP |
86 | static bool source_path_is_valid(const char *p) { |
87 | assert(p); | |
88 | ||
89 | if (*p == '+') | |
90 | p++; | |
91 | ||
92 | return path_is_absolute(p); | |
93 | } | |
94 | ||
95 | static char *resolve_source_path(const char *dest, const char *source) { | |
86c0dd4a LP |
96 | if (!source) |
97 | return NULL; | |
98 | ||
99 | if (source[0] == '+') | |
c6134d3e | 100 | return path_join(dest, source + 1); |
86c0dd4a LP |
101 | |
102 | return strdup(source); | |
103 | } | |
104 | ||
d0556c55 LP |
105 | static int allocate_temporary_source(CustomMount *m) { |
106 | assert(m); | |
107 | assert(!m->source); | |
108 | assert(!m->rm_rf_tmpdir); | |
109 | ||
110 | m->rm_rf_tmpdir = strdup("/var/tmp/nspawn-temp-XXXXXX"); | |
111 | if (!m->rm_rf_tmpdir) | |
112 | return log_oom(); | |
113 | ||
114 | if (!mkdtemp(m->rm_rf_tmpdir)) { | |
115 | m->rm_rf_tmpdir = mfree(m->rm_rf_tmpdir); | |
116 | return log_error_errno(errno, "Failed to acquire temporary directory: %m"); | |
117 | } | |
118 | ||
119 | m->source = path_join(m->rm_rf_tmpdir, "src"); | |
120 | if (!m->source) | |
121 | return log_oom(); | |
122 | ||
123 | if (mkdir(m->source, 0755) < 0) | |
124 | return log_error_errno(errno, "Failed to create %s: %m", m->source); | |
125 | ||
126 | return 0; | |
127 | } | |
128 | ||
88614c8a | 129 | int custom_mount_prepare_all(const char *dest, CustomMount *l, size_t n) { |
86c0dd4a LP |
130 | int r; |
131 | ||
132 | /* Prepare all custom mounts. This will make source we know all temporary directories. This is called in the | |
133 | * parent process, so that we know the temporary directories to remove on exit before we fork off the | |
134 | * children. */ | |
135 | ||
136 | assert(l || n == 0); | |
137 | ||
138 | /* Order the custom mounts, and make sure we have a working directory */ | |
93bab288 | 139 | typesafe_qsort(l, n, custom_mount_compare); |
86c0dd4a | 140 | |
d2b99ed7 | 141 | for (size_t i = 0; i < n; i++) { |
86c0dd4a LP |
142 | CustomMount *m = l + i; |
143 | ||
de40a303 LP |
144 | /* /proc we mount in the inner child, i.e. when we acquired CLONE_NEWPID. All other mounts we mount |
145 | * already in the outer child, so that the mounts are already established before CLONE_NEWPID and in | |
146 | * particular CLONE_NEWUSER. This also means any custom mounts below /proc also need to be mounted in | |
147 | * the inner child, not the outer one. Determine this here. */ | |
148 | m->in_userns = path_startswith(m->destination, "/proc"); | |
86c0dd4a | 149 | |
de40a303 LP |
150 | if (m->type == CUSTOM_MOUNT_BIND) { |
151 | if (m->source) { | |
152 | char *s; | |
86c0dd4a | 153 | |
de40a303 LP |
154 | s = resolve_source_path(dest, m->source); |
155 | if (!s) | |
156 | return log_oom(); | |
c7a4890c | 157 | |
de40a303 LP |
158 | free_and_replace(m->source, s); |
159 | } else { | |
160 | /* No source specified? In that case, use a throw-away temporary directory in /var/tmp */ | |
c7a4890c | 161 | |
d0556c55 LP |
162 | r = allocate_temporary_source(m); |
163 | if (r < 0) | |
164 | return r; | |
de40a303 | 165 | } |
86c0dd4a LP |
166 | } |
167 | ||
168 | if (m->type == CUSTOM_MOUNT_OVERLAY) { | |
169 | char **j; | |
170 | ||
171 | STRV_FOREACH(j, m->lower) { | |
172 | char *s; | |
173 | ||
174 | s = resolve_source_path(dest, *j); | |
175 | if (!s) | |
176 | return log_oom(); | |
177 | ||
10af01a5 | 178 | free_and_replace(*j, s); |
86c0dd4a LP |
179 | } |
180 | ||
d0556c55 LP |
181 | if (m->source) { |
182 | char *s; | |
183 | ||
184 | s = resolve_source_path(dest, m->source); | |
185 | if (!s) | |
186 | return log_oom(); | |
187 | ||
188 | free_and_replace(m->source, s); | |
189 | } else { | |
190 | r = allocate_temporary_source(m); | |
191 | if (r < 0) | |
192 | return r; | |
193 | } | |
194 | ||
86c0dd4a LP |
195 | if (m->work_dir) { |
196 | char *s; | |
197 | ||
198 | s = resolve_source_path(dest, m->work_dir); | |
199 | if (!s) | |
200 | return log_oom(); | |
201 | ||
10af01a5 | 202 | free_and_replace(m->work_dir, s); |
86c0dd4a | 203 | } else { |
86c0dd4a LP |
204 | r = tempfn_random(m->source, NULL, &m->work_dir); |
205 | if (r < 0) | |
206 | return log_error_errno(r, "Failed to acquire working directory: %m"); | |
207 | } | |
208 | ||
209 | (void) mkdir_label(m->work_dir, 0700); | |
210 | } | |
211 | } | |
212 | ||
213 | return 0; | |
214 | } | |
215 | ||
88614c8a | 216 | int bind_mount_parse(CustomMount **l, size_t *n, const char *s, bool read_only) { |
e83bebef LP |
217 | _cleanup_free_ char *source = NULL, *destination = NULL, *opts = NULL; |
218 | const char *p = s; | |
219 | CustomMount *m; | |
220 | int r; | |
221 | ||
222 | assert(l); | |
223 | assert(n); | |
224 | ||
225 | r = extract_many_words(&p, ":", EXTRACT_DONT_COALESCE_SEPARATORS, &source, &destination, NULL); | |
226 | if (r < 0) | |
227 | return r; | |
228 | if (r == 0) | |
229 | return -EINVAL; | |
e83bebef | 230 | if (r == 1) { |
86c0dd4a | 231 | destination = strdup(source[0] == '+' ? source+1 : source); |
e83bebef LP |
232 | if (!destination) |
233 | return -ENOMEM; | |
234 | } | |
e83bebef LP |
235 | if (r == 2 && !isempty(p)) { |
236 | opts = strdup(p); | |
237 | if (!opts) | |
238 | return -ENOMEM; | |
239 | } | |
240 | ||
c7a4890c | 241 | if (isempty(source)) |
0e636bf5 | 242 | source = mfree(source); |
c7a4890c | 243 | else if (!source_path_is_valid(source)) |
e83bebef | 244 | return -EINVAL; |
c7a4890c | 245 | |
e83bebef LP |
246 | if (!path_is_absolute(destination)) |
247 | return -EINVAL; | |
248 | ||
249 | m = custom_mount_add(l, n, CUSTOM_MOUNT_BIND); | |
250 | if (!m) | |
48cbe5f8 | 251 | return -ENOMEM; |
e83bebef | 252 | |
0e636bf5 ZJS |
253 | m->source = TAKE_PTR(source); |
254 | m->destination = TAKE_PTR(destination); | |
e83bebef | 255 | m->read_only = read_only; |
0e636bf5 | 256 | m->options = TAKE_PTR(opts); |
de40a303 | 257 | |
e83bebef LP |
258 | return 0; |
259 | } | |
260 | ||
88614c8a | 261 | int tmpfs_mount_parse(CustomMount **l, size_t *n, const char *s) { |
e83bebef LP |
262 | _cleanup_free_ char *path = NULL, *opts = NULL; |
263 | const char *p = s; | |
264 | CustomMount *m; | |
265 | int r; | |
266 | ||
267 | assert(l); | |
268 | assert(n); | |
269 | assert(s); | |
270 | ||
271 | r = extract_first_word(&p, &path, ":", EXTRACT_DONT_COALESCE_SEPARATORS); | |
272 | if (r < 0) | |
273 | return r; | |
274 | if (r == 0) | |
275 | return -EINVAL; | |
276 | ||
277 | if (isempty(p)) | |
278 | opts = strdup("mode=0755"); | |
279 | else | |
280 | opts = strdup(p); | |
281 | if (!opts) | |
282 | return -ENOMEM; | |
283 | ||
284 | if (!path_is_absolute(path)) | |
285 | return -EINVAL; | |
286 | ||
287 | m = custom_mount_add(l, n, CUSTOM_MOUNT_TMPFS); | |
288 | if (!m) | |
289 | return -ENOMEM; | |
290 | ||
1cc6c93a YW |
291 | m->destination = TAKE_PTR(path); |
292 | m->options = TAKE_PTR(opts); | |
e83bebef | 293 | |
e83bebef LP |
294 | return 0; |
295 | } | |
296 | ||
88614c8a | 297 | int overlay_mount_parse(CustomMount **l, size_t *n, const char *s, bool read_only) { |
ad85779a LP |
298 | _cleanup_free_ char *upper = NULL, *destination = NULL; |
299 | _cleanup_strv_free_ char **lower = NULL; | |
300 | CustomMount *m; | |
86c0dd4a | 301 | int k; |
ad85779a | 302 | |
90e30d76 | 303 | k = strv_split_full(&lower, s, ":", EXTRACT_DONT_COALESCE_SEPARATORS); |
86c0dd4a LP |
304 | if (k < 0) |
305 | return k; | |
ad85779a LP |
306 | if (k < 2) |
307 | return -EADDRNOTAVAIL; | |
308 | if (k == 2) { | |
86c0dd4a LP |
309 | /* If two parameters are specified, the first one is the lower, the second one the upper directory. And |
310 | * we'll also define the destination mount point the same as the upper. */ | |
311 | ||
312 | if (!source_path_is_valid(lower[0]) || | |
313 | !source_path_is_valid(lower[1])) | |
314 | return -EINVAL; | |
315 | ||
ae2a15bc | 316 | upper = TAKE_PTR(lower[1]); |
ad85779a | 317 | |
86c0dd4a | 318 | destination = strdup(upper[0] == '+' ? upper+1 : upper); /* take the destination without "+" prefix */ |
ad85779a LP |
319 | if (!destination) |
320 | return -ENOMEM; | |
ad85779a | 321 | } else { |
c7a4890c | 322 | char **i; |
86c0dd4a LP |
323 | |
324 | /* If more than two parameters are specified, the last one is the destination, the second to last one | |
325 | * the "upper", and all before that the "lower" directories. */ | |
326 | ||
ad85779a | 327 | destination = lower[k - 1]; |
ae2a15bc | 328 | upper = TAKE_PTR(lower[k - 2]); |
86c0dd4a | 329 | |
c7a4890c LP |
330 | STRV_FOREACH(i, lower) |
331 | if (!source_path_is_valid(*i)) | |
332 | return -EINVAL; | |
333 | ||
334 | /* If the upper directory is unspecified, then let's create it automatically as a throw-away directory | |
335 | * in /var/tmp */ | |
336 | if (isempty(upper)) | |
1d0c1146 | 337 | upper = mfree(upper); |
c7a4890c LP |
338 | else if (!source_path_is_valid(upper)) |
339 | return -EINVAL; | |
340 | ||
86c0dd4a LP |
341 | if (!path_is_absolute(destination)) |
342 | return -EINVAL; | |
ad85779a LP |
343 | } |
344 | ||
345 | m = custom_mount_add(l, n, CUSTOM_MOUNT_OVERLAY); | |
346 | if (!m) | |
347 | return -ENOMEM; | |
348 | ||
1cc6c93a YW |
349 | m->destination = TAKE_PTR(destination); |
350 | m->source = TAKE_PTR(upper); | |
351 | m->lower = TAKE_PTR(lower); | |
ad85779a LP |
352 | m->read_only = read_only; |
353 | ||
ad85779a LP |
354 | return 0; |
355 | } | |
356 | ||
de40a303 LP |
357 | int inaccessible_mount_parse(CustomMount **l, size_t *n, const char *s) { |
358 | _cleanup_free_ char *path = NULL; | |
359 | CustomMount *m; | |
360 | ||
361 | assert(l); | |
362 | assert(n); | |
363 | assert(s); | |
364 | ||
365 | if (!path_is_absolute(s)) | |
366 | return -EINVAL; | |
367 | ||
368 | path = strdup(s); | |
369 | if (!path) | |
370 | return -ENOMEM; | |
371 | ||
372 | m = custom_mount_add(l, n, CUSTOM_MOUNT_INACCESSIBLE); | |
373 | if (!m) | |
374 | return -ENOMEM; | |
375 | ||
376 | m->destination = TAKE_PTR(path); | |
377 | return 0; | |
378 | } | |
379 | ||
04029482 | 380 | int tmpfs_patch_options( |
e83bebef | 381 | const char *options, |
2fa017f1 | 382 | uid_t uid_shift, |
e83bebef LP |
383 | const char *selinux_apifs_context, |
384 | char **ret) { | |
385 | ||
cfea7618 | 386 | _cleanup_free_ char *buf = NULL; |
e83bebef | 387 | |
cfea7618 | 388 | assert(ret); |
e83bebef | 389 | |
cfea7618 YW |
390 | if (options) { |
391 | buf = strdup(options); | |
392 | if (!buf) | |
393 | return -ENOMEM; | |
e83bebef LP |
394 | } |
395 | ||
cfea7618 YW |
396 | if (uid_shift != UID_INVALID) |
397 | if (strextendf_with_separator(&buf, ",", "uid=" UID_FMT ",gid=" UID_FMT, uid_shift, uid_shift) < 0) | |
e83bebef | 398 | return -ENOMEM; |
e83bebef | 399 | |
cfea7618 YW |
400 | #if HAVE_SELINUX |
401 | if (selinux_apifs_context) | |
d3d15594 | 402 | if (strextendf_with_separator(&buf, ",", "context=\"%s\"", selinux_apifs_context) < 0) |
0996ef00 | 403 | return -ENOMEM; |
cfea7618 | 404 | #endif |
0996ef00 | 405 | |
cfea7618 YW |
406 | *ret = TAKE_PTR(buf); |
407 | return !!*ret; | |
e83bebef LP |
408 | } |
409 | ||
4f086aab | 410 | int mount_sysfs(const char *dest, MountSettingsMask mount_settings) { |
d8fc6a00 | 411 | const char *full, *top, *x; |
d1678248 | 412 | int r; |
4f086aab | 413 | unsigned long extra_flags = 0; |
d8fc6a00 LP |
414 | |
415 | top = prefix_roota(dest, "/sys"); | |
40fd52f2 | 416 | r = path_is_fs_type(top, SYSFS_MAGIC); |
d1678248 ILG |
417 | if (r < 0) |
418 | return log_error_errno(r, "Failed to determine filesystem type of %s: %m", top); | |
419 | /* /sys might already be mounted as sysfs by the outer child in the | |
420 | * !netns case. In this case, it's all good. Don't touch it because we | |
421 | * don't have the right to do so, see https://github.com/systemd/systemd/issues/1555. | |
422 | */ | |
423 | if (r > 0) | |
424 | return 0; | |
425 | ||
d8fc6a00 LP |
426 | full = prefix_roota(top, "/full"); |
427 | ||
428 | (void) mkdir(full, 0755); | |
429 | ||
bd6609eb | 430 | if (FLAGS_SET(mount_settings, MOUNT_APPLY_APIVFS_RO)) |
4f086aab SU |
431 | extra_flags |= MS_RDONLY; |
432 | ||
511a8cfe LP |
433 | r = mount_nofollow_verbose(LOG_ERR, "sysfs", full, "sysfs", |
434 | MS_NOSUID|MS_NOEXEC|MS_NODEV|extra_flags, NULL); | |
60e76d48 ZJS |
435 | if (r < 0) |
436 | return r; | |
d8fc6a00 LP |
437 | |
438 | FOREACH_STRING(x, "block", "bus", "class", "dev", "devices", "kernel") { | |
439 | _cleanup_free_ char *from = NULL, *to = NULL; | |
440 | ||
c6134d3e | 441 | from = path_join(full, x); |
d8fc6a00 LP |
442 | if (!from) |
443 | return log_oom(); | |
444 | ||
c6134d3e | 445 | to = path_join(top, x); |
d8fc6a00 LP |
446 | if (!to) |
447 | return log_oom(); | |
448 | ||
449 | (void) mkdir(to, 0755); | |
450 | ||
511a8cfe | 451 | r = mount_nofollow_verbose(LOG_ERR, from, to, NULL, MS_BIND, NULL); |
60e76d48 ZJS |
452 | if (r < 0) |
453 | return r; | |
d8fc6a00 | 454 | |
511a8cfe LP |
455 | r = mount_nofollow_verbose(LOG_ERR, NULL, to, NULL, |
456 | MS_BIND|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT|extra_flags, NULL); | |
60e76d48 ZJS |
457 | if (r < 0) |
458 | return r; | |
d8fc6a00 LP |
459 | } |
460 | ||
30f5d104 | 461 | r = umount_verbose(LOG_ERR, full, UMOUNT_NOFOLLOW); |
60e76d48 ZJS |
462 | if (r < 0) |
463 | return r; | |
d8fc6a00 LP |
464 | |
465 | if (rmdir(full) < 0) | |
466 | return log_error_errno(errno, "Failed to remove %s: %m", full); | |
467 | ||
0996ef00 CB |
468 | /* Create mountpoint for cgroups. Otherwise we are not allowed since we |
469 | * remount /sys read-only. | |
470 | */ | |
677a72cd LS |
471 | x = prefix_roota(top, "/fs/cgroup"); |
472 | (void) mkdir_p(x, 0755); | |
d8fc6a00 | 473 | |
511a8cfe LP |
474 | return mount_nofollow_verbose(LOG_ERR, NULL, top, NULL, |
475 | MS_BIND|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT|extra_flags, NULL); | |
d8fc6a00 LP |
476 | } |
477 | ||
e83bebef | 478 | int mount_all(const char *dest, |
4f086aab | 479 | MountSettingsMask mount_settings, |
2fa017f1 | 480 | uid_t uid_shift, |
e83bebef LP |
481 | const char *selinux_apifs_context) { |
482 | ||
de40a303 LP |
483 | #define PROC_INACCESSIBLE_REG(path) \ |
484 | { "/run/systemd/inaccessible/reg", (path), NULL, NULL, MS_BIND, \ | |
485 | MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* Bind mount first ... */ \ | |
d4b653c5 LP |
486 | { NULL, (path), NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, \ |
487 | MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO } /* Then, make it r/o */ | |
488 | ||
489 | #define PROC_READ_ONLY(path) \ | |
490 | { (path), (path), NULL, NULL, MS_BIND, \ | |
491 | MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* Bind mount first ... */ \ | |
492 | { NULL, (path), NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, \ | |
493 | MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO } /* Then, make it r/o */ | |
494 | ||
e83bebef LP |
495 | typedef struct MountPoint { |
496 | const char *what; | |
497 | const char *where; | |
498 | const char *type; | |
499 | const char *options; | |
500 | unsigned long flags; | |
4f086aab | 501 | MountSettingsMask mount_settings; |
e83bebef LP |
502 | } MountPoint; |
503 | ||
504 | static const MountPoint mount_table[] = { | |
d4b653c5 LP |
505 | /* First we list inner child mounts (i.e. mounts applied *after* entering user namespacing) */ |
506 | { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
511a8cfe | 507 | MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_MKDIR|MOUNT_FOLLOW_SYMLINKS }, /* we follow symlinks here since not following them requires /proc/ already being mounted, which we don't have here. */ |
d4b653c5 LP |
508 | |
509 | { "/proc/sys", "/proc/sys", NULL, NULL, MS_BIND, | |
510 | MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* Bind mount first ... */ | |
511 | ||
512 | { "/proc/sys/net", "/proc/sys/net", NULL, NULL, MS_BIND, | |
513 | MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO|MOUNT_APPLY_APIVFS_NETNS }, /* (except for this) */ | |
514 | ||
515 | { NULL, "/proc/sys", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, | |
516 | MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* ... then, make it r/o */ | |
517 | ||
518 | /* Make these files inaccessible to container payloads: they potentially leak information about kernel | |
519 | * internals or the host's execution environment to the container */ | |
de40a303 LP |
520 | PROC_INACCESSIBLE_REG("/proc/kallsyms"), |
521 | PROC_INACCESSIBLE_REG("/proc/kcore"), | |
522 | PROC_INACCESSIBLE_REG("/proc/keys"), | |
523 | PROC_INACCESSIBLE_REG("/proc/sysrq-trigger"), | |
524 | PROC_INACCESSIBLE_REG("/proc/timer_list"), | |
d4b653c5 LP |
525 | |
526 | /* Make these directories read-only to container payloads: they show hardware information, and in some | |
527 | * cases contain tunables the container really shouldn't have access to. */ | |
528 | PROC_READ_ONLY("/proc/acpi"), | |
529 | PROC_READ_ONLY("/proc/apm"), | |
530 | PROC_READ_ONLY("/proc/asound"), | |
531 | PROC_READ_ONLY("/proc/bus"), | |
532 | PROC_READ_ONLY("/proc/fs"), | |
533 | PROC_READ_ONLY("/proc/irq"), | |
534 | PROC_READ_ONLY("/proc/scsi"), | |
535 | ||
e1bb4b0d | 536 | { "mqueue", "/dev/mqueue", "mqueue", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
dcff2fa5 | 537 | MOUNT_IN_USERNS|MOUNT_MKDIR }, |
849b9b85 | 538 | |
d4b653c5 | 539 | /* Then we list outer child mounts (i.e. mounts applied *before* entering user namespacing) */ |
b67ec8e5 | 540 | { "tmpfs", "/tmp", "tmpfs", "mode=1777" NESTED_TMPFS_LIMITS, MS_NOSUID|MS_NODEV|MS_STRICTATIME, |
dcff2fa5 | 541 | MOUNT_FATAL|MOUNT_APPLY_TMPFS_TMP|MOUNT_MKDIR }, |
e1bb4b0d | 542 | { "tmpfs", "/sys", "tmpfs", "mode=555" TMPFS_LIMITS_SYS, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
dcff2fa5 | 543 | MOUNT_FATAL|MOUNT_APPLY_APIVFS_NETNS|MOUNT_MKDIR }, |
e1bb4b0d | 544 | { "sysfs", "/sys", "sysfs", NULL, MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, |
dcff2fa5 | 545 | MOUNT_FATAL|MOUNT_APPLY_APIVFS_RO|MOUNT_MKDIR }, /* skipped if above was mounted */ |
e1bb4b0d | 546 | { "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
dcff2fa5 | 547 | MOUNT_FATAL|MOUNT_MKDIR }, /* skipped if above was mounted */ |
e1bb4b0d | 548 | { "tmpfs", "/dev", "tmpfs", "mode=755" TMPFS_LIMITS_DEV, MS_NOSUID|MS_STRICTATIME, |
dcff2fa5 | 549 | MOUNT_FATAL|MOUNT_MKDIR }, |
b67ec8e5 | 550 | { "tmpfs", "/dev/shm", "tmpfs", "mode=1777" NESTED_TMPFS_LIMITS, MS_NOSUID|MS_NODEV|MS_STRICTATIME, |
dcff2fa5 | 551 | MOUNT_FATAL|MOUNT_MKDIR }, |
e1bb4b0d | 552 | { "tmpfs", "/run", "tmpfs", "mode=755" TMPFS_LIMITS_RUN, MS_NOSUID|MS_NODEV|MS_STRICTATIME, |
dcff2fa5 | 553 | MOUNT_FATAL|MOUNT_MKDIR }, |
d64e32c2 LP |
554 | { "/run/host", "/run/host", NULL, NULL, MS_BIND, |
555 | MOUNT_FATAL|MOUNT_MKDIR|MOUNT_PREFIX_ROOT }, /* Prepare this so that we can make it read-only when we are done */ | |
556 | { "/etc/os-release", "/run/host/os-release", NULL, NULL, MS_BIND, | |
557 | MOUNT_TOUCH }, /* As per kernel interface requirements, bind mount first (creating mount points) and make read-only later */ | |
558 | { "/usr/lib/os-release", "/run/host/os-release", NULL, NULL, MS_BIND, | |
559 | MOUNT_FATAL }, /* If /etc/os-release doesn't exist use the version in /usr/lib as fallback */ | |
560 | { NULL, "/run/host/os-release", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, | |
561 | MOUNT_FATAL }, | |
562 | { NULL, "/run/host", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, | |
563 | MOUNT_FATAL|MOUNT_IN_USERNS }, | |
349cc4a5 | 564 | #if HAVE_SELINUX |
e1bb4b0d | 565 | { "/sys/fs/selinux", "/sys/fs/selinux", NULL, NULL, MS_BIND, |
6fe01ced | 566 | MOUNT_MKDIR }, /* Bind mount first (mkdir/chown the mount point in case /sys/ is mounted as minimal skeleton tmpfs) */ |
e1bb4b0d | 567 | { NULL, "/sys/fs/selinux", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, |
6fe01ced | 568 | 0 }, /* Then, make it r/o (don't mkdir/chown the mount point here, the previous entry already did that) */ |
e83bebef LP |
569 | #endif |
570 | }; | |
571 | ||
bd6609eb DDM |
572 | bool use_userns = FLAGS_SET(mount_settings, MOUNT_USE_USERNS); |
573 | bool netns = FLAGS_SET(mount_settings, MOUNT_APPLY_APIVFS_NETNS); | |
574 | bool ro = FLAGS_SET(mount_settings, MOUNT_APPLY_APIVFS_RO); | |
575 | bool in_userns = FLAGS_SET(mount_settings, MOUNT_IN_USERNS); | |
576 | bool tmpfs_tmp = FLAGS_SET(mount_settings, MOUNT_APPLY_TMPFS_TMP); | |
88614c8a | 577 | int r; |
e83bebef | 578 | |
d2b99ed7 | 579 | for (size_t k = 0; k < ELEMENTSOF(mount_table); k++) { |
d64e32c2 | 580 | _cleanup_free_ char *where = NULL, *options = NULL, *prefixed = NULL; |
bd6609eb | 581 | bool fatal = FLAGS_SET(mount_table[k].mount_settings, MOUNT_FATAL); |
d64e32c2 | 582 | const char *o; |
4f086aab | 583 | |
bd6609eb | 584 | if (in_userns != FLAGS_SET(mount_table[k].mount_settings, MOUNT_IN_USERNS)) |
4f086aab | 585 | continue; |
e83bebef | 586 | |
bd6609eb | 587 | if (!netns && FLAGS_SET(mount_table[k].mount_settings, MOUNT_APPLY_APIVFS_NETNS)) |
d1678248 ILG |
588 | continue; |
589 | ||
bd6609eb | 590 | if (!ro && FLAGS_SET(mount_table[k].mount_settings, MOUNT_APPLY_APIVFS_RO)) |
e83bebef LP |
591 | continue; |
592 | ||
bd6609eb | 593 | if (!tmpfs_tmp && FLAGS_SET(mount_table[k].mount_settings, MOUNT_APPLY_TMPFS_TMP)) |
1099ceeb LP |
594 | continue; |
595 | ||
a5648b80 | 596 | r = chase_symlinks(mount_table[k].where, dest, CHASE_NONEXISTENT|CHASE_PREFIX_ROOT, &where, NULL); |
8ce48cf0 | 597 | if (r < 0) |
ec57bd42 | 598 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, mount_table[k].where); |
e83bebef | 599 | |
e83bebef | 600 | /* Skip this entry if it is not a remount. */ |
de40a303 LP |
601 | if (mount_table[k].what) { |
602 | r = path_is_mount_point(where, NULL, 0); | |
603 | if (r < 0 && r != -ENOENT) | |
604 | return log_error_errno(r, "Failed to detect whether %s is a mount point: %m", where); | |
605 | if (r > 0) | |
606 | continue; | |
607 | } | |
e83bebef | 608 | |
d64e32c2 | 609 | if ((mount_table[k].mount_settings & (MOUNT_MKDIR|MOUNT_TOUCH)) != 0) { |
b3b1a08a | 610 | uid_t u = (use_userns && !in_userns) ? uid_shift : UID_INVALID; |
e1bb4b0d LB |
611 | |
612 | if (FLAGS_SET(mount_table[k].mount_settings, MOUNT_TOUCH)) | |
613 | r = mkdir_parents_safe(dest, where, 0755, u, u, 0); | |
614 | else | |
615 | r = mkdir_p_safe(dest, where, 0755, u, u, 0); | |
dcff2fa5 LP |
616 | if (r < 0 && r != -EEXIST) { |
617 | if (fatal && r != -EROFS) | |
618 | return log_error_errno(r, "Failed to create directory %s: %m", where); | |
e83bebef | 619 | |
dcff2fa5 LP |
620 | log_debug_errno(r, "Failed to create directory %s: %m", where); |
621 | ||
622 | /* If we failed mkdir() or chown() due to the root directory being read only, | |
623 | * attempt to mount this fs anyway and let mount_verbose log any errors */ | |
624 | if (r != -EROFS) | |
625 | continue; | |
626 | } | |
d64e32c2 LP |
627 | } |
628 | ||
629 | if (FLAGS_SET(mount_table[k].mount_settings, MOUNT_TOUCH)) { | |
630 | r = touch(where); | |
631 | if (r < 0 && r != -EEXIST) { | |
632 | if (fatal && r != -EROFS) | |
633 | return log_error_errno(r, "Failed to create file %s: %m", where); | |
634 | ||
635 | log_debug_errno(r, "Failed to create file %s: %m", where); | |
636 | if (r != -EROFS) | |
637 | continue; | |
e1bb4b0d | 638 | } |
e83bebef LP |
639 | } |
640 | ||
641 | o = mount_table[k].options; | |
642 | if (streq_ptr(mount_table[k].type, "tmpfs")) { | |
2fa017f1 | 643 | r = tmpfs_patch_options(o, in_userns ? 0 : uid_shift, selinux_apifs_context, &options); |
e83bebef LP |
644 | if (r < 0) |
645 | return log_oom(); | |
646 | if (r > 0) | |
647 | o = options; | |
648 | } | |
649 | ||
d64e32c2 LP |
650 | if (FLAGS_SET(mount_table[k].mount_settings, MOUNT_PREFIX_ROOT)) { |
651 | /* Optionally prefix the mount source with the root dir. This is useful in bind | |
652 | * mounts to be created within the container image before we transition into it. Note | |
653 | * that MOUNT_IN_USERNS is run after we transitioned hence prefixing is not ncessary | |
654 | * for those. */ | |
655 | r = chase_symlinks(mount_table[k].what, dest, CHASE_PREFIX_ROOT, &prefixed, NULL); | |
656 | if (r < 0) | |
657 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, mount_table[k].what); | |
658 | } | |
659 | ||
511a8cfe LP |
660 | r = mount_verbose_full( |
661 | fatal ? LOG_ERR : LOG_DEBUG, | |
662 | prefixed ?: mount_table[k].what, | |
663 | where, | |
664 | mount_table[k].type, | |
665 | mount_table[k].flags, | |
666 | o, | |
667 | FLAGS_SET(mount_table[k].mount_settings, MOUNT_FOLLOW_SYMLINKS)); | |
4f086aab | 668 | if (r < 0 && fatal) |
60e76d48 | 669 | return r; |
e83bebef LP |
670 | } |
671 | ||
672 | return 0; | |
673 | } | |
674 | ||
c0c8f718 | 675 | static int parse_mount_bind_options(const char *options, unsigned long *mount_flags, char **mount_opts, bool *idmapped) { |
a11fd406 ILG |
676 | unsigned long flags = *mount_flags; |
677 | char *opts = NULL; | |
c0c8f718 | 678 | bool flag_idmapped = *idmapped; |
a11fd406 ILG |
679 | int r; |
680 | ||
681 | assert(options); | |
682 | ||
683 | for (;;) { | |
684 | _cleanup_free_ char *word = NULL; | |
685 | ||
d2b99ed7 | 686 | r = extract_first_word(&options, &word, ",", 0); |
a11fd406 ILG |
687 | if (r < 0) |
688 | return log_error_errno(r, "Failed to extract mount option: %m"); | |
689 | if (r == 0) | |
690 | break; | |
691 | ||
692 | if (streq(word, "rbind")) | |
693 | flags |= MS_REC; | |
694 | else if (streq(word, "norbind")) | |
695 | flags &= ~MS_REC; | |
c0c8f718 AV |
696 | else if (streq(word, "idmap")) |
697 | flag_idmapped = true; | |
698 | else if (streq(word, "noidmap")) | |
699 | flag_idmapped = false; | |
d2b99ed7 | 700 | else |
38288f0b | 701 | return log_error_errno(SYNTHETIC_ERRNO(EINVAL), |
d2b99ed7 | 702 | "Invalid bind mount option: %s", word); |
a11fd406 ILG |
703 | } |
704 | ||
705 | *mount_flags = flags; | |
c0c8f718 | 706 | *idmapped = flag_idmapped; |
a11fd406 ILG |
707 | /* in the future mount_opts will hold string options for mount(2) */ |
708 | *mount_opts = opts; | |
709 | ||
710 | return 0; | |
711 | } | |
712 | ||
c0c8f718 | 713 | static int mount_bind(const char *dest, CustomMount *m, uid_t uid_shift, uid_t uid_range) { |
a11fd406 ILG |
714 | _cleanup_free_ char *mount_opts = NULL, *where = NULL; |
715 | unsigned long mount_flags = MS_BIND | MS_REC; | |
68cf43c3 | 716 | struct stat source_st, dest_st; |
e83bebef | 717 | int r; |
c0c8f718 | 718 | bool idmapped = false; |
e83bebef | 719 | |
86c0dd4a | 720 | assert(dest); |
e83bebef LP |
721 | assert(m); |
722 | ||
a11fd406 | 723 | if (m->options) { |
c0c8f718 | 724 | r = parse_mount_bind_options(m->options, &mount_flags, &mount_opts, &idmapped); |
a11fd406 ILG |
725 | if (r < 0) |
726 | return r; | |
727 | } | |
728 | ||
07bca16f LP |
729 | /* If this is a bind mount from a temporary sources change ownership of the source to the container's |
730 | * root UID. Otherwise it would always show up as "nobody" if user namespacing is used. */ | |
731 | if (m->rm_rf_tmpdir && chown(m->source, uid_shift, uid_shift) < 0) | |
732 | return log_error_errno(errno, "Failed to chown %s: %m", m->source); | |
733 | ||
e83bebef LP |
734 | if (stat(m->source, &source_st) < 0) |
735 | return log_error_errno(errno, "Failed to stat %s: %m", m->source); | |
736 | ||
a5648b80 | 737 | r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); |
68cf43c3 | 738 | if (r < 0) |
ec57bd42 | 739 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); |
8ce48cf0 LP |
740 | if (r > 0) { /* Path exists already? */ |
741 | ||
742 | if (stat(where, &dest_st) < 0) | |
743 | return log_error_errno(errno, "Failed to stat %s: %m", where); | |
e83bebef | 744 | |
baaa35ad ZJS |
745 | if (S_ISDIR(source_st.st_mode) && !S_ISDIR(dest_st.st_mode)) |
746 | return log_error_errno(SYNTHETIC_ERRNO(EINVAL), | |
747 | "Cannot bind mount directory %s on file %s.", | |
748 | m->source, where); | |
749 | ||
750 | if (!S_ISDIR(source_st.st_mode) && S_ISDIR(dest_st.st_mode)) | |
751 | return log_error_errno(SYNTHETIC_ERRNO(EINVAL), | |
752 | "Cannot bind mount file %s on directory %s.", | |
753 | m->source, where); | |
e83bebef | 754 | |
8ce48cf0 | 755 | } else { /* Path doesn't exist yet? */ |
e83bebef LP |
756 | r = mkdir_parents_label(where, 0755); |
757 | if (r < 0) | |
758 | return log_error_errno(r, "Failed to make parents of %s: %m", where); | |
b97e83cb BN |
759 | |
760 | /* Create the mount point. Any non-directory file can be | |
761 | * mounted on any non-directory file (regular, fifo, socket, | |
762 | * char, block). | |
763 | */ | |
764 | if (S_ISDIR(source_st.st_mode)) | |
765 | r = mkdir_label(where, 0755); | |
766 | else | |
767 | r = touch(where); | |
768 | if (r < 0) | |
769 | return log_error_errno(r, "Failed to create mount point %s: %m", where); | |
8ce48cf0 | 770 | } |
e83bebef | 771 | |
511a8cfe | 772 | r = mount_nofollow_verbose(LOG_ERR, m->source, where, NULL, mount_flags, mount_opts); |
60e76d48 ZJS |
773 | if (r < 0) |
774 | return r; | |
e83bebef LP |
775 | |
776 | if (m->read_only) { | |
64e82c19 | 777 | r = bind_remount_recursive(where, MS_RDONLY, MS_RDONLY, NULL); |
e83bebef LP |
778 | if (r < 0) |
779 | return log_error_errno(r, "Read-only bind mount failed: %m"); | |
780 | } | |
781 | ||
c0c8f718 AV |
782 | if (idmapped) { |
783 | r = remount_idmap(where, uid_shift, uid_range); | |
784 | if (r < 0) | |
785 | return log_error_errno(r, "Failed to map ids for bind mount %s: %m", where); | |
786 | } | |
787 | ||
e83bebef LP |
788 | return 0; |
789 | } | |
790 | ||
e091a5df | 791 | static int mount_tmpfs(const char *dest, CustomMount *m, uid_t uid_shift, const char *selinux_apifs_context) { |
68cf43c3 LP |
792 | const char *options; |
793 | _cleanup_free_ char *buf = NULL, *where = NULL; | |
e83bebef LP |
794 | int r; |
795 | ||
796 | assert(dest); | |
797 | assert(m); | |
798 | ||
a5648b80 | 799 | r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); |
68cf43c3 | 800 | if (r < 0) |
ec57bd42 | 801 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); |
8ce48cf0 LP |
802 | if (r == 0) { /* Doesn't exist yet? */ |
803 | r = mkdir_p_label(where, 0755); | |
804 | if (r < 0) | |
805 | return log_error_errno(r, "Creating mount point for tmpfs %s failed: %m", where); | |
806 | } | |
e83bebef | 807 | |
2fa017f1 | 808 | r = tmpfs_patch_options(m->options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); |
e83bebef LP |
809 | if (r < 0) |
810 | return log_oom(); | |
811 | options = r > 0 ? buf : m->options; | |
812 | ||
511a8cfe | 813 | return mount_nofollow_verbose(LOG_ERR, "tmpfs", where, "tmpfs", MS_NODEV|MS_STRICTATIME, options); |
e83bebef LP |
814 | } |
815 | ||
86c0dd4a | 816 | static char *joined_and_escaped_lower_dirs(char **lower) { |
e83bebef LP |
817 | _cleanup_strv_free_ char **sv = NULL; |
818 | ||
819 | sv = strv_copy(lower); | |
820 | if (!sv) | |
821 | return NULL; | |
822 | ||
823 | strv_reverse(sv); | |
824 | ||
825 | if (!strv_shell_escape(sv, ",:")) | |
826 | return NULL; | |
827 | ||
828 | return strv_join(sv, ":"); | |
829 | } | |
830 | ||
831 | static int mount_overlay(const char *dest, CustomMount *m) { | |
86c0dd4a | 832 | _cleanup_free_ char *lower = NULL, *where = NULL, *escaped_source = NULL; |
68cf43c3 | 833 | const char *options; |
e83bebef LP |
834 | int r; |
835 | ||
836 | assert(dest); | |
837 | assert(m); | |
838 | ||
a5648b80 | 839 | r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); |
68cf43c3 | 840 | if (r < 0) |
ec57bd42 | 841 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); |
8ce48cf0 LP |
842 | if (r == 0) { /* Doesn't exist yet? */ |
843 | r = mkdir_label(where, 0755); | |
844 | if (r < 0) | |
845 | return log_error_errno(r, "Creating mount point for overlay %s failed: %m", where); | |
846 | } | |
e83bebef LP |
847 | |
848 | (void) mkdir_p_label(m->source, 0755); | |
849 | ||
850 | lower = joined_and_escaped_lower_dirs(m->lower); | |
851 | if (!lower) | |
852 | return log_oom(); | |
853 | ||
86c0dd4a LP |
854 | escaped_source = shell_escape(m->source, ",:"); |
855 | if (!escaped_source) | |
856 | return log_oom(); | |
e83bebef | 857 | |
86c0dd4a | 858 | if (m->read_only) |
e83bebef | 859 | options = strjoina("lowerdir=", escaped_source, ":", lower); |
86c0dd4a LP |
860 | else { |
861 | _cleanup_free_ char *escaped_work_dir = NULL; | |
e83bebef | 862 | |
e83bebef LP |
863 | escaped_work_dir = shell_escape(m->work_dir, ",:"); |
864 | if (!escaped_work_dir) | |
865 | return log_oom(); | |
866 | ||
867 | options = strjoina("lowerdir=", lower, ",upperdir=", escaped_source, ",workdir=", escaped_work_dir); | |
868 | } | |
869 | ||
511a8cfe | 870 | return mount_nofollow_verbose(LOG_ERR, "overlay", where, "overlay", m->read_only ? MS_RDONLY : 0, options); |
e83bebef LP |
871 | } |
872 | ||
de40a303 | 873 | static int mount_inaccessible(const char *dest, CustomMount *m) { |
e5f10caf | 874 | _cleanup_free_ char *where = NULL, *source = NULL; |
de40a303 LP |
875 | struct stat st; |
876 | int r; | |
877 | ||
878 | assert(dest); | |
879 | assert(m); | |
880 | ||
a5648b80 | 881 | r = chase_symlinks_and_stat(m->destination, dest, CHASE_PREFIX_ROOT, &where, &st, NULL); |
de40a303 LP |
882 | if (r < 0) { |
883 | log_full_errno(m->graceful ? LOG_DEBUG : LOG_ERR, r, "Failed to resolve %s/%s: %m", dest, m->destination); | |
884 | return m->graceful ? 0 : r; | |
885 | } | |
886 | ||
48b747fa | 887 | r = mode_to_inaccessible_node(NULL, st.st_mode, &source); |
e5f10caf AZ |
888 | if (r < 0) |
889 | return m->graceful ? 0 : r; | |
de40a303 | 890 | |
511a8cfe | 891 | r = mount_nofollow_verbose(m->graceful ? LOG_DEBUG : LOG_ERR, source, where, NULL, MS_BIND, NULL); |
de40a303 LP |
892 | if (r < 0) |
893 | return m->graceful ? 0 : r; | |
894 | ||
511a8cfe | 895 | r = mount_nofollow_verbose(m->graceful ? LOG_DEBUG : LOG_ERR, NULL, where, NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, NULL); |
2c9b7a7e | 896 | if (r < 0) { |
30f5d104 | 897 | (void) umount_verbose(m->graceful ? LOG_DEBUG : LOG_ERR, where, UMOUNT_NOFOLLOW); |
de40a303 | 898 | return m->graceful ? 0 : r; |
2c9b7a7e | 899 | } |
de40a303 LP |
900 | |
901 | return 0; | |
902 | } | |
903 | ||
904 | static int mount_arbitrary(const char *dest, CustomMount *m) { | |
905 | _cleanup_free_ char *where = NULL; | |
906 | int r; | |
907 | ||
908 | assert(dest); | |
909 | assert(m); | |
910 | ||
a5648b80 | 911 | r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); |
de40a303 LP |
912 | if (r < 0) |
913 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); | |
914 | if (r == 0) { /* Doesn't exist yet? */ | |
915 | r = mkdir_p_label(where, 0755); | |
916 | if (r < 0) | |
917 | return log_error_errno(r, "Creating mount point for mount %s failed: %m", where); | |
918 | } | |
919 | ||
511a8cfe | 920 | return mount_nofollow_verbose(LOG_ERR, m->source, where, m->type_argument, 0, m->options); |
de40a303 LP |
921 | } |
922 | ||
e83bebef LP |
923 | int mount_custom( |
924 | const char *dest, | |
88614c8a | 925 | CustomMount *mounts, size_t n, |
e091a5df | 926 | uid_t uid_shift, |
c0c8f718 | 927 | uid_t uid_range, |
de40a303 | 928 | const char *selinux_apifs_context, |
5f0a6347 | 929 | MountSettingsMask mount_settings) { |
e83bebef LP |
930 | int r; |
931 | ||
932 | assert(dest); | |
933 | ||
d2b99ed7 | 934 | for (size_t i = 0; i < n; i++) { |
e83bebef LP |
935 | CustomMount *m = mounts + i; |
936 | ||
bd6609eb | 937 | if (FLAGS_SET(mount_settings, MOUNT_IN_USERNS) != m->in_userns) |
5f0a6347 DDM |
938 | continue; |
939 | ||
bd6609eb | 940 | if (FLAGS_SET(mount_settings, MOUNT_ROOT_ONLY) && !path_equal(m->destination, "/")) |
5f0a6347 DDM |
941 | continue; |
942 | ||
bd6609eb | 943 | if (FLAGS_SET(mount_settings, MOUNT_NON_ROOT_ONLY) && path_equal(m->destination, "/")) |
de40a303 LP |
944 | continue; |
945 | ||
e83bebef LP |
946 | switch (m->type) { |
947 | ||
948 | case CUSTOM_MOUNT_BIND: | |
c0c8f718 | 949 | r = mount_bind(dest, m, uid_shift, uid_range); |
e83bebef LP |
950 | break; |
951 | ||
952 | case CUSTOM_MOUNT_TMPFS: | |
e091a5df | 953 | r = mount_tmpfs(dest, m, uid_shift, selinux_apifs_context); |
e83bebef LP |
954 | break; |
955 | ||
956 | case CUSTOM_MOUNT_OVERLAY: | |
957 | r = mount_overlay(dest, m); | |
958 | break; | |
959 | ||
de40a303 LP |
960 | case CUSTOM_MOUNT_INACCESSIBLE: |
961 | r = mount_inaccessible(dest, m); | |
962 | break; | |
963 | ||
964 | case CUSTOM_MOUNT_ARBITRARY: | |
965 | r = mount_arbitrary(dest, m); | |
966 | break; | |
967 | ||
e83bebef | 968 | default: |
04499a70 | 969 | assert_not_reached(); |
e83bebef LP |
970 | } |
971 | ||
972 | if (r < 0) | |
973 | return r; | |
974 | } | |
975 | ||
976 | return 0; | |
977 | } | |
978 | ||
bbd407ea | 979 | bool has_custom_root_mount(const CustomMount *mounts, size_t n) { |
d2b99ed7 ZJS |
980 | for (size_t i = 0; i < n; i++) |
981 | if (path_equal(mounts[i].destination, "/")) | |
bbd407ea | 982 | return true; |
bbd407ea DDM |
983 | |
984 | return false; | |
985 | } | |
986 | ||
e091a5df | 987 | static int setup_volatile_state(const char *directory, uid_t uid_shift, const char *selinux_apifs_context) { |
e83bebef LP |
988 | _cleanup_free_ char *buf = NULL; |
989 | const char *p, *options; | |
990 | int r; | |
991 | ||
992 | assert(directory); | |
993 | ||
e5b43a04 | 994 | /* --volatile=state means we simply overmount /var with a tmpfs, and the rest read-only. */ |
e83bebef | 995 | |
64e82c19 | 996 | r = bind_remount_recursive(directory, MS_RDONLY, MS_RDONLY, NULL); |
e83bebef LP |
997 | if (r < 0) |
998 | return log_error_errno(r, "Failed to remount %s read-only: %m", directory); | |
999 | ||
1000 | p = prefix_roota(directory, "/var"); | |
1001 | r = mkdir(p, 0755); | |
1002 | if (r < 0 && errno != EEXIST) | |
1003 | return log_error_errno(errno, "Failed to create %s: %m", directory); | |
1004 | ||
7d85383e | 1005 | options = "mode=755" TMPFS_LIMITS_VOLATILE_STATE; |
2fa017f1 | 1006 | r = tmpfs_patch_options(options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); |
e83bebef LP |
1007 | if (r < 0) |
1008 | return log_oom(); | |
1009 | if (r > 0) | |
1010 | options = buf; | |
1011 | ||
511a8cfe | 1012 | return mount_nofollow_verbose(LOG_ERR, "tmpfs", p, "tmpfs", MS_STRICTATIME, options); |
e83bebef LP |
1013 | } |
1014 | ||
e091a5df | 1015 | static int setup_volatile_yes(const char *directory, uid_t uid_shift, const char *selinux_apifs_context) { |
e83bebef LP |
1016 | bool tmpfs_mounted = false, bind_mounted = false; |
1017 | char template[] = "/tmp/nspawn-volatile-XXXXXX"; | |
07b9f3f0 | 1018 | _cleanup_free_ char *buf = NULL, *bindir = NULL; |
e83bebef | 1019 | const char *f, *t, *options; |
07b9f3f0 | 1020 | struct stat st; |
e83bebef LP |
1021 | int r; |
1022 | ||
1023 | assert(directory); | |
1024 | ||
07b9f3f0 LP |
1025 | /* --volatile=yes means we mount a tmpfs to the root dir, and the original /usr to use inside it, and |
1026 | * that read-only. Before we start setting this up let's validate if the image has the /usr merge | |
1027 | * implemented, and let's output a friendly log message if it hasn't. */ | |
1028 | ||
1029 | bindir = path_join(directory, "/bin"); | |
1030 | if (!bindir) | |
1031 | return log_oom(); | |
1032 | if (lstat(bindir, &st) < 0) { | |
1033 | if (errno != ENOENT) | |
1034 | return log_error_errno(errno, "Failed to stat /bin directory below image: %m"); | |
1035 | ||
1036 | /* ENOENT is fine, just means the image is probably just a naked /usr and we can create the | |
1037 | * rest. */ | |
1038 | } else if (S_ISDIR(st.st_mode)) | |
1039 | return log_error_errno(SYNTHETIC_ERRNO(EISDIR), | |
1040 | "Sorry, --volatile=yes mode is not supported with OS images that have not merged /bin/, /sbin/, /lib/, /lib64/ into /usr/. " | |
1041 | "Please work with your distribution and help them adopt the merged /usr scheme."); | |
1042 | else if (!S_ISLNK(st.st_mode)) | |
1043 | return log_error_errno(SYNTHETIC_ERRNO(EINVAL), | |
1044 | "Error starting image: if --volatile=yes is used /bin must be a symlink (for merged /usr support) or non-existent (in which case a symlink is created automatically)."); | |
e83bebef LP |
1045 | |
1046 | if (!mkdtemp(template)) | |
1047 | return log_error_errno(errno, "Failed to create temporary directory: %m"); | |
1048 | ||
7d85383e | 1049 | options = "mode=755" TMPFS_LIMITS_ROOTFS; |
2fa017f1 | 1050 | r = tmpfs_patch_options(options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); |
e83bebef | 1051 | if (r < 0) |
c55d0ae7 | 1052 | goto fail; |
e83bebef LP |
1053 | if (r > 0) |
1054 | options = buf; | |
1055 | ||
511a8cfe | 1056 | r = mount_nofollow_verbose(LOG_ERR, "tmpfs", template, "tmpfs", MS_STRICTATIME, options); |
60e76d48 | 1057 | if (r < 0) |
e83bebef | 1058 | goto fail; |
e83bebef LP |
1059 | |
1060 | tmpfs_mounted = true; | |
1061 | ||
1062 | f = prefix_roota(directory, "/usr"); | |
1063 | t = prefix_roota(template, "/usr"); | |
1064 | ||
1065 | r = mkdir(t, 0755); | |
1066 | if (r < 0 && errno != EEXIST) { | |
1067 | r = log_error_errno(errno, "Failed to create %s: %m", t); | |
1068 | goto fail; | |
1069 | } | |
1070 | ||
511a8cfe | 1071 | r = mount_nofollow_verbose(LOG_ERR, f, t, NULL, MS_BIND|MS_REC, NULL); |
60e76d48 | 1072 | if (r < 0) |
e83bebef | 1073 | goto fail; |
e83bebef LP |
1074 | |
1075 | bind_mounted = true; | |
1076 | ||
64e82c19 | 1077 | r = bind_remount_recursive(t, MS_RDONLY, MS_RDONLY, NULL); |
e83bebef LP |
1078 | if (r < 0) { |
1079 | log_error_errno(r, "Failed to remount %s read-only: %m", t); | |
1080 | goto fail; | |
1081 | } | |
1082 | ||
511a8cfe | 1083 | r = mount_nofollow_verbose(LOG_ERR, template, directory, NULL, MS_MOVE, NULL); |
60e76d48 | 1084 | if (r < 0) |
e83bebef | 1085 | goto fail; |
e83bebef LP |
1086 | |
1087 | (void) rmdir(template); | |
1088 | ||
1089 | return 0; | |
1090 | ||
1091 | fail: | |
1092 | if (bind_mounted) | |
30f5d104 | 1093 | (void) umount_verbose(LOG_ERR, t, UMOUNT_NOFOLLOW); |
e83bebef LP |
1094 | |
1095 | if (tmpfs_mounted) | |
30f5d104 LP |
1096 | (void) umount_verbose(LOG_ERR, template, UMOUNT_NOFOLLOW); |
1097 | ||
e83bebef LP |
1098 | (void) rmdir(template); |
1099 | return r; | |
1100 | } | |
b53ede69 | 1101 | |
e091a5df | 1102 | static int setup_volatile_overlay(const char *directory, uid_t uid_shift, const char *selinux_apifs_context) { |
6c610aca LP |
1103 | _cleanup_free_ char *buf = NULL, *escaped_directory = NULL, *escaped_upper = NULL, *escaped_work = NULL; |
1104 | char template[] = "/tmp/nspawn-volatile-XXXXXX"; | |
1105 | const char *upper, *work, *options; | |
1106 | bool tmpfs_mounted = false; | |
1107 | int r; | |
1108 | ||
1109 | assert(directory); | |
1110 | ||
1111 | /* --volatile=overlay means we mount an overlayfs to the root dir. */ | |
1112 | ||
1113 | if (!mkdtemp(template)) | |
1114 | return log_error_errno(errno, "Failed to create temporary directory: %m"); | |
1115 | ||
7d85383e | 1116 | options = "mode=755" TMPFS_LIMITS_ROOTFS; |
6c610aca LP |
1117 | r = tmpfs_patch_options(options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); |
1118 | if (r < 0) | |
1119 | goto finish; | |
1120 | if (r > 0) | |
1121 | options = buf; | |
1122 | ||
511a8cfe | 1123 | r = mount_nofollow_verbose(LOG_ERR, "tmpfs", template, "tmpfs", MS_STRICTATIME, options); |
6c610aca LP |
1124 | if (r < 0) |
1125 | goto finish; | |
1126 | ||
1127 | tmpfs_mounted = true; | |
1128 | ||
1129 | upper = strjoina(template, "/upper"); | |
1130 | work = strjoina(template, "/work"); | |
1131 | ||
1132 | if (mkdir(upper, 0755) < 0) { | |
1133 | r = log_error_errno(errno, "Failed to create %s: %m", upper); | |
1134 | goto finish; | |
1135 | } | |
1136 | if (mkdir(work, 0755) < 0) { | |
1137 | r = log_error_errno(errno, "Failed to create %s: %m", work); | |
1138 | goto finish; | |
1139 | } | |
1140 | ||
1141 | /* And now, let's overmount the root dir with an overlayfs that uses the root dir as lower dir. It's kinda nice | |
1142 | * that the kernel allows us to do that without going through some mount point rearrangements. */ | |
1143 | ||
1144 | escaped_directory = shell_escape(directory, ",:"); | |
1145 | escaped_upper = shell_escape(upper, ",:"); | |
1146 | escaped_work = shell_escape(work, ",:"); | |
1147 | if (!escaped_directory || !escaped_upper || !escaped_work) { | |
1148 | r = -ENOMEM; | |
1149 | goto finish; | |
1150 | } | |
1151 | ||
1152 | options = strjoina("lowerdir=", escaped_directory, ",upperdir=", escaped_upper, ",workdir=", escaped_work); | |
511a8cfe | 1153 | r = mount_nofollow_verbose(LOG_ERR, "overlay", directory, "overlay", 0, options); |
6c610aca LP |
1154 | |
1155 | finish: | |
1156 | if (tmpfs_mounted) | |
30f5d104 | 1157 | (void) umount_verbose(LOG_ERR, template, UMOUNT_NOFOLLOW); |
6c610aca LP |
1158 | |
1159 | (void) rmdir(template); | |
1160 | return r; | |
1161 | } | |
1162 | ||
e5b43a04 LP |
1163 | int setup_volatile_mode( |
1164 | const char *directory, | |
1165 | VolatileMode mode, | |
e091a5df | 1166 | uid_t uid_shift, |
e5b43a04 LP |
1167 | const char *selinux_apifs_context) { |
1168 | ||
1169 | switch (mode) { | |
1170 | ||
1171 | case VOLATILE_YES: | |
e091a5df | 1172 | return setup_volatile_yes(directory, uid_shift, selinux_apifs_context); |
e5b43a04 LP |
1173 | |
1174 | case VOLATILE_STATE: | |
e091a5df | 1175 | return setup_volatile_state(directory, uid_shift, selinux_apifs_context); |
e5b43a04 | 1176 | |
6c610aca | 1177 | case VOLATILE_OVERLAY: |
e091a5df | 1178 | return setup_volatile_overlay(directory, uid_shift, selinux_apifs_context); |
6c610aca | 1179 | |
e5b43a04 LP |
1180 | default: |
1181 | return 0; | |
1182 | } | |
1183 | } | |
1184 | ||
b53ede69 PW |
1185 | /* Expects *pivot_root_new and *pivot_root_old to be initialised to allocated memory or NULL. */ |
1186 | int pivot_root_parse(char **pivot_root_new, char **pivot_root_old, const char *s) { | |
1187 | _cleanup_free_ char *root_new = NULL, *root_old = NULL; | |
1188 | const char *p = s; | |
1189 | int r; | |
1190 | ||
1191 | assert(pivot_root_new); | |
1192 | assert(pivot_root_old); | |
1193 | ||
1194 | r = extract_first_word(&p, &root_new, ":", EXTRACT_DONT_COALESCE_SEPARATORS); | |
1195 | if (r < 0) | |
1196 | return r; | |
1197 | if (r == 0) | |
1198 | return -EINVAL; | |
1199 | ||
1200 | if (isempty(p)) | |
1201 | root_old = NULL; | |
1202 | else { | |
1203 | root_old = strdup(p); | |
1204 | if (!root_old) | |
1205 | return -ENOMEM; | |
1206 | } | |
1207 | ||
1208 | if (!path_is_absolute(root_new)) | |
1209 | return -EINVAL; | |
1210 | if (root_old && !path_is_absolute(root_old)) | |
1211 | return -EINVAL; | |
1212 | ||
1213 | free_and_replace(*pivot_root_new, root_new); | |
1214 | free_and_replace(*pivot_root_old, root_old); | |
1215 | ||
1216 | return 0; | |
1217 | } | |
1218 | ||
1219 | int setup_pivot_root(const char *directory, const char *pivot_root_new, const char *pivot_root_old) { | |
1220 | _cleanup_free_ char *directory_pivot_root_new = NULL; | |
1221 | _cleanup_free_ char *pivot_tmp_pivot_root_old = NULL; | |
1222 | char pivot_tmp[] = "/tmp/nspawn-pivot-XXXXXX"; | |
1223 | bool remove_pivot_tmp = false; | |
1224 | int r; | |
1225 | ||
1226 | assert(directory); | |
1227 | ||
1228 | if (!pivot_root_new) | |
1229 | return 0; | |
1230 | ||
1231 | /* Pivot pivot_root_new to / and the existing / to pivot_root_old. | |
1232 | * If pivot_root_old is NULL, the existing / disappears. | |
1233 | * This requires a temporary directory, pivot_tmp, which is | |
1234 | * not a child of either. | |
1235 | * | |
1236 | * This is typically used for OSTree-style containers, where | |
1237 | * the root partition contains several sysroots which could be | |
1238 | * run. Normally, one would be chosen by the bootloader and | |
1239 | * pivoted to / by initramfs. | |
1240 | * | |
1241 | * For example, for an OSTree deployment, pivot_root_new | |
1242 | * would be: /ostree/deploy/$os/deploy/$checksum. Note that this | |
1243 | * code doesn’t do the /var mount which OSTree expects: use | |
1244 | * --bind +/sysroot/ostree/deploy/$os/var:/var for that. | |
1245 | * | |
1246 | * So in the OSTree case, we’ll end up with something like: | |
1247 | * - directory = /tmp/nspawn-root-123456 | |
1248 | * - pivot_root_new = /ostree/deploy/os/deploy/123abc | |
1249 | * - pivot_root_old = /sysroot | |
1250 | * - directory_pivot_root_new = | |
1251 | * /tmp/nspawn-root-123456/ostree/deploy/os/deploy/123abc | |
1252 | * - pivot_tmp = /tmp/nspawn-pivot-123456 | |
1253 | * - pivot_tmp_pivot_root_old = /tmp/nspawn-pivot-123456/sysroot | |
1254 | * | |
1255 | * Requires all file systems at directory and below to be mounted | |
1256 | * MS_PRIVATE or MS_SLAVE so they can be moved. | |
1257 | */ | |
c6134d3e LP |
1258 | directory_pivot_root_new = path_join(directory, pivot_root_new); |
1259 | if (!directory_pivot_root_new) | |
1260 | return log_oom(); | |
b53ede69 PW |
1261 | |
1262 | /* Remount directory_pivot_root_new to make it movable. */ | |
511a8cfe | 1263 | r = mount_nofollow_verbose(LOG_ERR, directory_pivot_root_new, directory_pivot_root_new, NULL, MS_BIND, NULL); |
b53ede69 PW |
1264 | if (r < 0) |
1265 | goto done; | |
1266 | ||
1267 | if (pivot_root_old) { | |
1268 | if (!mkdtemp(pivot_tmp)) { | |
1269 | r = log_error_errno(errno, "Failed to create temporary directory: %m"); | |
1270 | goto done; | |
1271 | } | |
1272 | ||
1273 | remove_pivot_tmp = true; | |
c6134d3e LP |
1274 | pivot_tmp_pivot_root_old = path_join(pivot_tmp, pivot_root_old); |
1275 | if (!pivot_tmp_pivot_root_old) { | |
1276 | r = log_oom(); | |
1277 | goto done; | |
1278 | } | |
b53ede69 | 1279 | |
511a8cfe | 1280 | r = mount_nofollow_verbose(LOG_ERR, directory_pivot_root_new, pivot_tmp, NULL, MS_MOVE, NULL); |
b53ede69 PW |
1281 | if (r < 0) |
1282 | goto done; | |
1283 | ||
511a8cfe | 1284 | r = mount_nofollow_verbose(LOG_ERR, directory, pivot_tmp_pivot_root_old, NULL, MS_MOVE, NULL); |
b53ede69 PW |
1285 | if (r < 0) |
1286 | goto done; | |
1287 | ||
511a8cfe | 1288 | r = mount_nofollow_verbose(LOG_ERR, pivot_tmp, directory, NULL, MS_MOVE, NULL); |
b53ede69 PW |
1289 | if (r < 0) |
1290 | goto done; | |
1291 | } else { | |
511a8cfe | 1292 | r = mount_nofollow_verbose(LOG_ERR, directory_pivot_root_new, directory, NULL, MS_MOVE, NULL); |
b53ede69 PW |
1293 | if (r < 0) |
1294 | goto done; | |
1295 | } | |
1296 | ||
1297 | done: | |
1298 | if (remove_pivot_tmp) | |
1299 | (void) rmdir(pivot_tmp); | |
1300 | ||
1301 | return r; | |
1302 | } |