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Commit | Line | Data |
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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
e83bebef | 2 | |
4f5dd394 | 3 | #include <sys/mount.h> |
07630cea | 4 | #include <linux/magic.h> |
e83bebef | 5 | |
b5efdb8a | 6 | #include "alloc-util.h" |
4f5dd394 | 7 | #include "escape.h" |
0996ef00 | 8 | #include "fd-util.h" |
ca78ad1d | 9 | #include "format-util.h" |
f4f15635 | 10 | #include "fs-util.h" |
e83bebef | 11 | #include "label.h" |
4f5dd394 | 12 | #include "mkdir.h" |
4349cd7c | 13 | #include "mount-util.h" |
049af8ad | 14 | #include "mountpoint-util.h" |
6bedfcbb LP |
15 | #include "nspawn-mount.h" |
16 | #include "parse-util.h" | |
4f5dd394 LP |
17 | #include "path-util.h" |
18 | #include "rm-rf.h" | |
e83bebef | 19 | #include "set.h" |
760877e9 | 20 | #include "sort-util.h" |
8fcde012 | 21 | #include "stat-util.h" |
07630cea | 22 | #include "string-util.h" |
4f5dd394 | 23 | #include "strv.h" |
e4de7287 | 24 | #include "tmpfile-util.h" |
ee104e11 | 25 | #include "user-util.h" |
e83bebef | 26 | |
88614c8a | 27 | CustomMount* custom_mount_add(CustomMount **l, size_t *n, CustomMountType t) { |
e83bebef LP |
28 | CustomMount *c, *ret; |
29 | ||
30 | assert(l); | |
31 | assert(n); | |
32 | assert(t >= 0); | |
33 | assert(t < _CUSTOM_MOUNT_TYPE_MAX); | |
34 | ||
aa484f35 | 35 | c = reallocarray(*l, *n + 1, sizeof(CustomMount)); |
e83bebef LP |
36 | if (!c) |
37 | return NULL; | |
38 | ||
39 | *l = c; | |
40 | ret = *l + *n; | |
41 | (*n)++; | |
42 | ||
43 | *ret = (CustomMount) { .type = t }; | |
44 | ||
45 | return ret; | |
46 | } | |
47 | ||
88614c8a LP |
48 | void custom_mount_free_all(CustomMount *l, size_t n) { |
49 | size_t i; | |
e83bebef LP |
50 | |
51 | for (i = 0; i < n; i++) { | |
52 | CustomMount *m = l + i; | |
53 | ||
54 | free(m->source); | |
55 | free(m->destination); | |
56 | free(m->options); | |
57 | ||
58 | if (m->work_dir) { | |
59 | (void) rm_rf(m->work_dir, REMOVE_ROOT|REMOVE_PHYSICAL); | |
60 | free(m->work_dir); | |
61 | } | |
62 | ||
c7a4890c LP |
63 | if (m->rm_rf_tmpdir) { |
64 | (void) rm_rf(m->rm_rf_tmpdir, REMOVE_ROOT|REMOVE_PHYSICAL); | |
65 | free(m->rm_rf_tmpdir); | |
66 | } | |
67 | ||
e83bebef | 68 | strv_free(m->lower); |
de40a303 | 69 | free(m->type_argument); |
e83bebef LP |
70 | } |
71 | ||
72 | free(l); | |
73 | } | |
74 | ||
93bab288 | 75 | static int custom_mount_compare(const CustomMount *a, const CustomMount *b) { |
e83bebef LP |
76 | int r; |
77 | ||
93bab288 | 78 | r = path_compare(a->destination, b->destination); |
e83bebef LP |
79 | if (r != 0) |
80 | return r; | |
81 | ||
93bab288 | 82 | return CMP(a->type, b->type); |
e83bebef LP |
83 | } |
84 | ||
86c0dd4a LP |
85 | static bool source_path_is_valid(const char *p) { |
86 | assert(p); | |
87 | ||
88 | if (*p == '+') | |
89 | p++; | |
90 | ||
91 | return path_is_absolute(p); | |
92 | } | |
93 | ||
94 | static char *resolve_source_path(const char *dest, const char *source) { | |
95 | ||
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 LP |
129 | int custom_mount_prepare_all(const char *dest, CustomMount *l, size_t n) { |
130 | size_t i; | |
86c0dd4a LP |
131 | int r; |
132 | ||
133 | /* Prepare all custom mounts. This will make source we know all temporary directories. This is called in the | |
134 | * parent process, so that we know the temporary directories to remove on exit before we fork off the | |
135 | * children. */ | |
136 | ||
137 | assert(l || n == 0); | |
138 | ||
139 | /* Order the custom mounts, and make sure we have a working directory */ | |
93bab288 | 140 | typesafe_qsort(l, n, custom_mount_compare); |
86c0dd4a LP |
141 | |
142 | for (i = 0; i < n; i++) { | |
143 | CustomMount *m = l + i; | |
144 | ||
de40a303 LP |
145 | /* /proc we mount in the inner child, i.e. when we acquired CLONE_NEWPID. All other mounts we mount |
146 | * already in the outer child, so that the mounts are already established before CLONE_NEWPID and in | |
147 | * particular CLONE_NEWUSER. This also means any custom mounts below /proc also need to be mounted in | |
148 | * the inner child, not the outer one. Determine this here. */ | |
149 | m->in_userns = path_startswith(m->destination, "/proc"); | |
86c0dd4a | 150 | |
de40a303 LP |
151 | if (m->type == CUSTOM_MOUNT_BIND) { |
152 | if (m->source) { | |
153 | char *s; | |
86c0dd4a | 154 | |
de40a303 LP |
155 | s = resolve_source_path(dest, m->source); |
156 | if (!s) | |
157 | return log_oom(); | |
c7a4890c | 158 | |
de40a303 LP |
159 | free_and_replace(m->source, s); |
160 | } else { | |
161 | /* No source specified? In that case, use a throw-away temporary directory in /var/tmp */ | |
c7a4890c | 162 | |
d0556c55 LP |
163 | r = allocate_temporary_source(m); |
164 | if (r < 0) | |
165 | return r; | |
de40a303 | 166 | } |
86c0dd4a LP |
167 | } |
168 | ||
169 | if (m->type == CUSTOM_MOUNT_OVERLAY) { | |
170 | char **j; | |
171 | ||
172 | STRV_FOREACH(j, m->lower) { | |
173 | char *s; | |
174 | ||
175 | s = resolve_source_path(dest, *j); | |
176 | if (!s) | |
177 | return log_oom(); | |
178 | ||
10af01a5 | 179 | free_and_replace(*j, s); |
86c0dd4a LP |
180 | } |
181 | ||
d0556c55 LP |
182 | if (m->source) { |
183 | char *s; | |
184 | ||
185 | s = resolve_source_path(dest, m->source); | |
186 | if (!s) | |
187 | return log_oom(); | |
188 | ||
189 | free_and_replace(m->source, s); | |
190 | } else { | |
191 | r = allocate_temporary_source(m); | |
192 | if (r < 0) | |
193 | return r; | |
194 | } | |
195 | ||
86c0dd4a LP |
196 | if (m->work_dir) { |
197 | char *s; | |
198 | ||
199 | s = resolve_source_path(dest, m->work_dir); | |
200 | if (!s) | |
201 | return log_oom(); | |
202 | ||
10af01a5 | 203 | free_and_replace(m->work_dir, s); |
86c0dd4a | 204 | } else { |
86c0dd4a LP |
205 | r = tempfn_random(m->source, NULL, &m->work_dir); |
206 | if (r < 0) | |
207 | return log_error_errno(r, "Failed to acquire working directory: %m"); | |
208 | } | |
209 | ||
210 | (void) mkdir_label(m->work_dir, 0700); | |
211 | } | |
212 | } | |
213 | ||
214 | return 0; | |
215 | } | |
216 | ||
88614c8a | 217 | int bind_mount_parse(CustomMount **l, size_t *n, const char *s, bool read_only) { |
e83bebef LP |
218 | _cleanup_free_ char *source = NULL, *destination = NULL, *opts = NULL; |
219 | const char *p = s; | |
220 | CustomMount *m; | |
221 | int r; | |
222 | ||
223 | assert(l); | |
224 | assert(n); | |
225 | ||
226 | r = extract_many_words(&p, ":", EXTRACT_DONT_COALESCE_SEPARATORS, &source, &destination, NULL); | |
227 | if (r < 0) | |
228 | return r; | |
229 | if (r == 0) | |
230 | return -EINVAL; | |
e83bebef | 231 | if (r == 1) { |
86c0dd4a | 232 | destination = strdup(source[0] == '+' ? source+1 : source); |
e83bebef LP |
233 | if (!destination) |
234 | return -ENOMEM; | |
235 | } | |
e83bebef LP |
236 | if (r == 2 && !isempty(p)) { |
237 | opts = strdup(p); | |
238 | if (!opts) | |
239 | return -ENOMEM; | |
240 | } | |
241 | ||
c7a4890c | 242 | if (isempty(source)) |
0e636bf5 | 243 | source = mfree(source); |
c7a4890c | 244 | else if (!source_path_is_valid(source)) |
e83bebef | 245 | return -EINVAL; |
c7a4890c | 246 | |
e83bebef LP |
247 | if (!path_is_absolute(destination)) |
248 | return -EINVAL; | |
249 | ||
250 | m = custom_mount_add(l, n, CUSTOM_MOUNT_BIND); | |
251 | if (!m) | |
48cbe5f8 | 252 | return -ENOMEM; |
e83bebef | 253 | |
0e636bf5 ZJS |
254 | m->source = TAKE_PTR(source); |
255 | m->destination = TAKE_PTR(destination); | |
e83bebef | 256 | m->read_only = read_only; |
0e636bf5 | 257 | m->options = TAKE_PTR(opts); |
de40a303 | 258 | |
e83bebef LP |
259 | return 0; |
260 | } | |
261 | ||
88614c8a | 262 | int tmpfs_mount_parse(CustomMount **l, size_t *n, const char *s) { |
e83bebef LP |
263 | _cleanup_free_ char *path = NULL, *opts = NULL; |
264 | const char *p = s; | |
265 | CustomMount *m; | |
266 | int r; | |
267 | ||
268 | assert(l); | |
269 | assert(n); | |
270 | assert(s); | |
271 | ||
272 | r = extract_first_word(&p, &path, ":", EXTRACT_DONT_COALESCE_SEPARATORS); | |
273 | if (r < 0) | |
274 | return r; | |
275 | if (r == 0) | |
276 | return -EINVAL; | |
277 | ||
278 | if (isempty(p)) | |
279 | opts = strdup("mode=0755"); | |
280 | else | |
281 | opts = strdup(p); | |
282 | if (!opts) | |
283 | return -ENOMEM; | |
284 | ||
285 | if (!path_is_absolute(path)) | |
286 | return -EINVAL; | |
287 | ||
288 | m = custom_mount_add(l, n, CUSTOM_MOUNT_TMPFS); | |
289 | if (!m) | |
290 | return -ENOMEM; | |
291 | ||
1cc6c93a YW |
292 | m->destination = TAKE_PTR(path); |
293 | m->options = TAKE_PTR(opts); | |
e83bebef | 294 | |
e83bebef LP |
295 | return 0; |
296 | } | |
297 | ||
88614c8a | 298 | int overlay_mount_parse(CustomMount **l, size_t *n, const char *s, bool read_only) { |
ad85779a LP |
299 | _cleanup_free_ char *upper = NULL, *destination = NULL; |
300 | _cleanup_strv_free_ char **lower = NULL; | |
301 | CustomMount *m; | |
86c0dd4a | 302 | int k; |
ad85779a | 303 | |
86c0dd4a LP |
304 | k = strv_split_extract(&lower, s, ":", EXTRACT_DONT_COALESCE_SEPARATORS); |
305 | if (k < 0) | |
306 | return k; | |
ad85779a LP |
307 | if (k < 2) |
308 | return -EADDRNOTAVAIL; | |
309 | if (k == 2) { | |
86c0dd4a LP |
310 | /* If two parameters are specified, the first one is the lower, the second one the upper directory. And |
311 | * we'll also define the destination mount point the same as the upper. */ | |
312 | ||
313 | if (!source_path_is_valid(lower[0]) || | |
314 | !source_path_is_valid(lower[1])) | |
315 | return -EINVAL; | |
316 | ||
ae2a15bc | 317 | upper = TAKE_PTR(lower[1]); |
ad85779a | 318 | |
86c0dd4a | 319 | destination = strdup(upper[0] == '+' ? upper+1 : upper); /* take the destination without "+" prefix */ |
ad85779a LP |
320 | if (!destination) |
321 | return -ENOMEM; | |
ad85779a | 322 | } else { |
c7a4890c | 323 | char **i; |
86c0dd4a LP |
324 | |
325 | /* If more than two parameters are specified, the last one is the destination, the second to last one | |
326 | * the "upper", and all before that the "lower" directories. */ | |
327 | ||
ad85779a | 328 | destination = lower[k - 1]; |
ae2a15bc | 329 | upper = TAKE_PTR(lower[k - 2]); |
86c0dd4a | 330 | |
c7a4890c LP |
331 | STRV_FOREACH(i, lower) |
332 | if (!source_path_is_valid(*i)) | |
333 | return -EINVAL; | |
334 | ||
335 | /* If the upper directory is unspecified, then let's create it automatically as a throw-away directory | |
336 | * in /var/tmp */ | |
337 | if (isempty(upper)) | |
1d0c1146 | 338 | upper = mfree(upper); |
c7a4890c LP |
339 | else if (!source_path_is_valid(upper)) |
340 | return -EINVAL; | |
341 | ||
86c0dd4a LP |
342 | if (!path_is_absolute(destination)) |
343 | return -EINVAL; | |
ad85779a LP |
344 | } |
345 | ||
346 | m = custom_mount_add(l, n, CUSTOM_MOUNT_OVERLAY); | |
347 | if (!m) | |
348 | return -ENOMEM; | |
349 | ||
1cc6c93a YW |
350 | m->destination = TAKE_PTR(destination); |
351 | m->source = TAKE_PTR(upper); | |
352 | m->lower = TAKE_PTR(lower); | |
ad85779a LP |
353 | m->read_only = read_only; |
354 | ||
ad85779a LP |
355 | return 0; |
356 | } | |
357 | ||
de40a303 LP |
358 | int inaccessible_mount_parse(CustomMount **l, size_t *n, const char *s) { |
359 | _cleanup_free_ char *path = NULL; | |
360 | CustomMount *m; | |
361 | ||
362 | assert(l); | |
363 | assert(n); | |
364 | assert(s); | |
365 | ||
366 | if (!path_is_absolute(s)) | |
367 | return -EINVAL; | |
368 | ||
369 | path = strdup(s); | |
370 | if (!path) | |
371 | return -ENOMEM; | |
372 | ||
373 | m = custom_mount_add(l, n, CUSTOM_MOUNT_INACCESSIBLE); | |
374 | if (!m) | |
375 | return -ENOMEM; | |
376 | ||
377 | m->destination = TAKE_PTR(path); | |
378 | return 0; | |
379 | } | |
380 | ||
04029482 | 381 | int tmpfs_patch_options( |
e83bebef | 382 | const char *options, |
2fa017f1 | 383 | uid_t uid_shift, |
e83bebef LP |
384 | const char *selinux_apifs_context, |
385 | char **ret) { | |
386 | ||
387 | char *buf = NULL; | |
388 | ||
2fa017f1 | 389 | if (uid_shift != UID_INVALID) { |
9aa2169e | 390 | if (asprintf(&buf, "%s%suid=" UID_FMT ",gid=" UID_FMT, |
87e4e28d | 391 | strempty(options), options ? "," : "", |
9aa2169e | 392 | uid_shift, uid_shift) < 0) |
e83bebef LP |
393 | return -ENOMEM; |
394 | ||
395 | options = buf; | |
396 | } | |
397 | ||
349cc4a5 | 398 | #if HAVE_SELINUX |
e83bebef LP |
399 | if (selinux_apifs_context) { |
400 | char *t; | |
401 | ||
87e4e28d | 402 | t = strjoin(strempty(options), options ? "," : "", |
9aa2169e ZJS |
403 | "context=\"", selinux_apifs_context, "\""); |
404 | free(buf); | |
405 | if (!t) | |
e83bebef | 406 | return -ENOMEM; |
e83bebef | 407 | |
e83bebef LP |
408 | buf = t; |
409 | } | |
410 | #endif | |
411 | ||
0996ef00 CB |
412 | if (!buf && options) { |
413 | buf = strdup(options); | |
414 | if (!buf) | |
415 | return -ENOMEM; | |
416 | } | |
e83bebef | 417 | *ret = buf; |
0996ef00 | 418 | |
e83bebef LP |
419 | return !!buf; |
420 | } | |
421 | ||
4f086aab | 422 | int mount_sysfs(const char *dest, MountSettingsMask mount_settings) { |
d8fc6a00 | 423 | const char *full, *top, *x; |
d1678248 | 424 | int r; |
4f086aab | 425 | unsigned long extra_flags = 0; |
d8fc6a00 LP |
426 | |
427 | top = prefix_roota(dest, "/sys"); | |
40fd52f2 | 428 | r = path_is_fs_type(top, SYSFS_MAGIC); |
d1678248 ILG |
429 | if (r < 0) |
430 | return log_error_errno(r, "Failed to determine filesystem type of %s: %m", top); | |
431 | /* /sys might already be mounted as sysfs by the outer child in the | |
432 | * !netns case. In this case, it's all good. Don't touch it because we | |
433 | * don't have the right to do so, see https://github.com/systemd/systemd/issues/1555. | |
434 | */ | |
435 | if (r > 0) | |
436 | return 0; | |
437 | ||
d8fc6a00 LP |
438 | full = prefix_roota(top, "/full"); |
439 | ||
440 | (void) mkdir(full, 0755); | |
441 | ||
bd6609eb | 442 | if (FLAGS_SET(mount_settings, MOUNT_APPLY_APIVFS_RO)) |
4f086aab SU |
443 | extra_flags |= MS_RDONLY; |
444 | ||
60e76d48 | 445 | r = mount_verbose(LOG_ERR, "sysfs", full, "sysfs", |
4f086aab | 446 | MS_NOSUID|MS_NOEXEC|MS_NODEV|extra_flags, NULL); |
60e76d48 ZJS |
447 | if (r < 0) |
448 | return r; | |
d8fc6a00 LP |
449 | |
450 | FOREACH_STRING(x, "block", "bus", "class", "dev", "devices", "kernel") { | |
451 | _cleanup_free_ char *from = NULL, *to = NULL; | |
452 | ||
c6134d3e | 453 | from = path_join(full, x); |
d8fc6a00 LP |
454 | if (!from) |
455 | return log_oom(); | |
456 | ||
c6134d3e | 457 | to = path_join(top, x); |
d8fc6a00 LP |
458 | if (!to) |
459 | return log_oom(); | |
460 | ||
461 | (void) mkdir(to, 0755); | |
462 | ||
60e76d48 ZJS |
463 | r = mount_verbose(LOG_ERR, from, to, NULL, MS_BIND, NULL); |
464 | if (r < 0) | |
465 | return r; | |
d8fc6a00 | 466 | |
60e76d48 | 467 | r = mount_verbose(LOG_ERR, NULL, to, NULL, |
4f086aab | 468 | MS_BIND|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT|extra_flags, NULL); |
60e76d48 ZJS |
469 | if (r < 0) |
470 | return r; | |
d8fc6a00 LP |
471 | } |
472 | ||
60e76d48 ZJS |
473 | r = umount_verbose(full); |
474 | if (r < 0) | |
475 | return r; | |
d8fc6a00 LP |
476 | |
477 | if (rmdir(full) < 0) | |
478 | return log_error_errno(errno, "Failed to remove %s: %m", full); | |
479 | ||
0996ef00 CB |
480 | /* Create mountpoint for cgroups. Otherwise we are not allowed since we |
481 | * remount /sys read-only. | |
482 | */ | |
677a72cd LS |
483 | x = prefix_roota(top, "/fs/cgroup"); |
484 | (void) mkdir_p(x, 0755); | |
d8fc6a00 | 485 | |
60e76d48 | 486 | return mount_verbose(LOG_ERR, NULL, top, NULL, |
4f086aab | 487 | MS_BIND|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT|extra_flags, NULL); |
d8fc6a00 LP |
488 | } |
489 | ||
e83bebef | 490 | int mount_all(const char *dest, |
4f086aab | 491 | MountSettingsMask mount_settings, |
2fa017f1 | 492 | uid_t uid_shift, |
e83bebef LP |
493 | const char *selinux_apifs_context) { |
494 | ||
de40a303 LP |
495 | #define PROC_INACCESSIBLE_REG(path) \ |
496 | { "/run/systemd/inaccessible/reg", (path), NULL, NULL, MS_BIND, \ | |
497 | MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* Bind mount first ... */ \ | |
d4b653c5 LP |
498 | { NULL, (path), NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, \ |
499 | MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO } /* Then, make it r/o */ | |
500 | ||
501 | #define PROC_READ_ONLY(path) \ | |
502 | { (path), (path), NULL, NULL, MS_BIND, \ | |
503 | MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* Bind mount first ... */ \ | |
504 | { NULL, (path), NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, \ | |
505 | MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO } /* Then, make it r/o */ | |
506 | ||
e83bebef LP |
507 | typedef struct MountPoint { |
508 | const char *what; | |
509 | const char *where; | |
510 | const char *type; | |
511 | const char *options; | |
512 | unsigned long flags; | |
4f086aab | 513 | MountSettingsMask mount_settings; |
e83bebef LP |
514 | } MountPoint; |
515 | ||
516 | static const MountPoint mount_table[] = { | |
d4b653c5 LP |
517 | /* First we list inner child mounts (i.e. mounts applied *after* entering user namespacing) */ |
518 | { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
dcff2fa5 | 519 | MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_MKDIR }, |
d4b653c5 LP |
520 | |
521 | { "/proc/sys", "/proc/sys", NULL, NULL, MS_BIND, | |
522 | MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* Bind mount first ... */ | |
523 | ||
524 | { "/proc/sys/net", "/proc/sys/net", NULL, NULL, MS_BIND, | |
525 | MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO|MOUNT_APPLY_APIVFS_NETNS }, /* (except for this) */ | |
526 | ||
527 | { NULL, "/proc/sys", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, | |
528 | MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* ... then, make it r/o */ | |
529 | ||
530 | /* Make these files inaccessible to container payloads: they potentially leak information about kernel | |
531 | * internals or the host's execution environment to the container */ | |
de40a303 LP |
532 | PROC_INACCESSIBLE_REG("/proc/kallsyms"), |
533 | PROC_INACCESSIBLE_REG("/proc/kcore"), | |
534 | PROC_INACCESSIBLE_REG("/proc/keys"), | |
535 | PROC_INACCESSIBLE_REG("/proc/sysrq-trigger"), | |
536 | PROC_INACCESSIBLE_REG("/proc/timer_list"), | |
d4b653c5 LP |
537 | |
538 | /* Make these directories read-only to container payloads: they show hardware information, and in some | |
539 | * cases contain tunables the container really shouldn't have access to. */ | |
540 | PROC_READ_ONLY("/proc/acpi"), | |
541 | PROC_READ_ONLY("/proc/apm"), | |
542 | PROC_READ_ONLY("/proc/asound"), | |
543 | PROC_READ_ONLY("/proc/bus"), | |
544 | PROC_READ_ONLY("/proc/fs"), | |
545 | PROC_READ_ONLY("/proc/irq"), | |
546 | PROC_READ_ONLY("/proc/scsi"), | |
547 | ||
e1bb4b0d | 548 | { "mqueue", "/dev/mqueue", "mqueue", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
dcff2fa5 | 549 | MOUNT_IN_USERNS|MOUNT_MKDIR }, |
849b9b85 | 550 | |
d4b653c5 | 551 | /* Then we list outer child mounts (i.e. mounts applied *before* entering user namespacing) */ |
b67ec8e5 | 552 | { "tmpfs", "/tmp", "tmpfs", "mode=1777" NESTED_TMPFS_LIMITS, MS_NOSUID|MS_NODEV|MS_STRICTATIME, |
dcff2fa5 | 553 | MOUNT_FATAL|MOUNT_APPLY_TMPFS_TMP|MOUNT_MKDIR }, |
e1bb4b0d | 554 | { "tmpfs", "/sys", "tmpfs", "mode=555" TMPFS_LIMITS_SYS, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
dcff2fa5 | 555 | MOUNT_FATAL|MOUNT_APPLY_APIVFS_NETNS|MOUNT_MKDIR }, |
e1bb4b0d | 556 | { "sysfs", "/sys", "sysfs", NULL, MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, |
dcff2fa5 | 557 | MOUNT_FATAL|MOUNT_APPLY_APIVFS_RO|MOUNT_MKDIR }, /* skipped if above was mounted */ |
e1bb4b0d | 558 | { "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
dcff2fa5 | 559 | MOUNT_FATAL|MOUNT_MKDIR }, /* skipped if above was mounted */ |
e1bb4b0d | 560 | { "tmpfs", "/dev", "tmpfs", "mode=755" TMPFS_LIMITS_DEV, MS_NOSUID|MS_STRICTATIME, |
dcff2fa5 | 561 | MOUNT_FATAL|MOUNT_MKDIR }, |
b67ec8e5 | 562 | { "tmpfs", "/dev/shm", "tmpfs", "mode=1777" NESTED_TMPFS_LIMITS, MS_NOSUID|MS_NODEV|MS_STRICTATIME, |
dcff2fa5 | 563 | MOUNT_FATAL|MOUNT_MKDIR }, |
e1bb4b0d | 564 | { "tmpfs", "/run", "tmpfs", "mode=755" TMPFS_LIMITS_RUN, MS_NOSUID|MS_NODEV|MS_STRICTATIME, |
dcff2fa5 | 565 | MOUNT_FATAL|MOUNT_MKDIR }, |
d64e32c2 LP |
566 | { "/run/host", "/run/host", NULL, NULL, MS_BIND, |
567 | MOUNT_FATAL|MOUNT_MKDIR|MOUNT_PREFIX_ROOT }, /* Prepare this so that we can make it read-only when we are done */ | |
568 | { "/etc/os-release", "/run/host/os-release", NULL, NULL, MS_BIND, | |
569 | MOUNT_TOUCH }, /* As per kernel interface requirements, bind mount first (creating mount points) and make read-only later */ | |
570 | { "/usr/lib/os-release", "/run/host/os-release", NULL, NULL, MS_BIND, | |
571 | MOUNT_FATAL }, /* If /etc/os-release doesn't exist use the version in /usr/lib as fallback */ | |
572 | { NULL, "/run/host/os-release", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, | |
573 | MOUNT_FATAL }, | |
574 | { NULL, "/run/host", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, | |
575 | MOUNT_FATAL|MOUNT_IN_USERNS }, | |
349cc4a5 | 576 | #if HAVE_SELINUX |
e1bb4b0d | 577 | { "/sys/fs/selinux", "/sys/fs/selinux", NULL, NULL, MS_BIND, |
6fe01ced | 578 | MOUNT_MKDIR }, /* Bind mount first (mkdir/chown the mount point in case /sys/ is mounted as minimal skeleton tmpfs) */ |
e1bb4b0d | 579 | { NULL, "/sys/fs/selinux", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, |
6fe01ced | 580 | 0 }, /* Then, make it r/o (don't mkdir/chown the mount point here, the previous entry already did that) */ |
e83bebef LP |
581 | #endif |
582 | }; | |
583 | ||
bd6609eb DDM |
584 | bool use_userns = FLAGS_SET(mount_settings, MOUNT_USE_USERNS); |
585 | bool netns = FLAGS_SET(mount_settings, MOUNT_APPLY_APIVFS_NETNS); | |
586 | bool ro = FLAGS_SET(mount_settings, MOUNT_APPLY_APIVFS_RO); | |
587 | bool in_userns = FLAGS_SET(mount_settings, MOUNT_IN_USERNS); | |
588 | bool tmpfs_tmp = FLAGS_SET(mount_settings, MOUNT_APPLY_TMPFS_TMP); | |
d4b653c5 | 589 | size_t k; |
88614c8a | 590 | int r; |
e83bebef LP |
591 | |
592 | for (k = 0; k < ELEMENTSOF(mount_table); k++) { | |
d64e32c2 | 593 | _cleanup_free_ char *where = NULL, *options = NULL, *prefixed = NULL; |
bd6609eb | 594 | bool fatal = FLAGS_SET(mount_table[k].mount_settings, MOUNT_FATAL); |
d64e32c2 | 595 | const char *o; |
4f086aab | 596 | |
bd6609eb | 597 | if (in_userns != FLAGS_SET(mount_table[k].mount_settings, MOUNT_IN_USERNS)) |
4f086aab | 598 | continue; |
e83bebef | 599 | |
bd6609eb | 600 | if (!netns && FLAGS_SET(mount_table[k].mount_settings, MOUNT_APPLY_APIVFS_NETNS)) |
d1678248 ILG |
601 | continue; |
602 | ||
bd6609eb | 603 | if (!ro && FLAGS_SET(mount_table[k].mount_settings, MOUNT_APPLY_APIVFS_RO)) |
e83bebef LP |
604 | continue; |
605 | ||
bd6609eb | 606 | if (!tmpfs_tmp && FLAGS_SET(mount_table[k].mount_settings, MOUNT_APPLY_TMPFS_TMP)) |
1099ceeb LP |
607 | continue; |
608 | ||
a5648b80 | 609 | r = chase_symlinks(mount_table[k].where, dest, CHASE_NONEXISTENT|CHASE_PREFIX_ROOT, &where, NULL); |
8ce48cf0 | 610 | if (r < 0) |
ec57bd42 | 611 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, mount_table[k].where); |
e83bebef | 612 | |
e83bebef | 613 | /* Skip this entry if it is not a remount. */ |
de40a303 LP |
614 | if (mount_table[k].what) { |
615 | r = path_is_mount_point(where, NULL, 0); | |
616 | if (r < 0 && r != -ENOENT) | |
617 | return log_error_errno(r, "Failed to detect whether %s is a mount point: %m", where); | |
618 | if (r > 0) | |
619 | continue; | |
620 | } | |
e83bebef | 621 | |
d64e32c2 | 622 | if ((mount_table[k].mount_settings & (MOUNT_MKDIR|MOUNT_TOUCH)) != 0) { |
b3b1a08a | 623 | uid_t u = (use_userns && !in_userns) ? uid_shift : UID_INVALID; |
e1bb4b0d LB |
624 | |
625 | if (FLAGS_SET(mount_table[k].mount_settings, MOUNT_TOUCH)) | |
626 | r = mkdir_parents_safe(dest, where, 0755, u, u, 0); | |
627 | else | |
628 | r = mkdir_p_safe(dest, where, 0755, u, u, 0); | |
dcff2fa5 LP |
629 | if (r < 0 && r != -EEXIST) { |
630 | if (fatal && r != -EROFS) | |
631 | return log_error_errno(r, "Failed to create directory %s: %m", where); | |
e83bebef | 632 | |
dcff2fa5 LP |
633 | log_debug_errno(r, "Failed to create directory %s: %m", where); |
634 | ||
635 | /* If we failed mkdir() or chown() due to the root directory being read only, | |
636 | * attempt to mount this fs anyway and let mount_verbose log any errors */ | |
637 | if (r != -EROFS) | |
638 | continue; | |
639 | } | |
d64e32c2 LP |
640 | } |
641 | ||
642 | if (FLAGS_SET(mount_table[k].mount_settings, MOUNT_TOUCH)) { | |
643 | r = touch(where); | |
644 | if (r < 0 && r != -EEXIST) { | |
645 | if (fatal && r != -EROFS) | |
646 | return log_error_errno(r, "Failed to create file %s: %m", where); | |
647 | ||
648 | log_debug_errno(r, "Failed to create file %s: %m", where); | |
649 | if (r != -EROFS) | |
650 | continue; | |
e1bb4b0d | 651 | } |
e83bebef LP |
652 | } |
653 | ||
654 | o = mount_table[k].options; | |
655 | if (streq_ptr(mount_table[k].type, "tmpfs")) { | |
2fa017f1 | 656 | r = tmpfs_patch_options(o, in_userns ? 0 : uid_shift, selinux_apifs_context, &options); |
e83bebef LP |
657 | if (r < 0) |
658 | return log_oom(); | |
659 | if (r > 0) | |
660 | o = options; | |
661 | } | |
662 | ||
d64e32c2 LP |
663 | if (FLAGS_SET(mount_table[k].mount_settings, MOUNT_PREFIX_ROOT)) { |
664 | /* Optionally prefix the mount source with the root dir. This is useful in bind | |
665 | * mounts to be created within the container image before we transition into it. Note | |
666 | * that MOUNT_IN_USERNS is run after we transitioned hence prefixing is not ncessary | |
667 | * for those. */ | |
668 | r = chase_symlinks(mount_table[k].what, dest, CHASE_PREFIX_ROOT, &prefixed, NULL); | |
669 | if (r < 0) | |
670 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, mount_table[k].what); | |
671 | } | |
672 | ||
4f086aab | 673 | r = mount_verbose(fatal ? LOG_ERR : LOG_DEBUG, |
d64e32c2 | 674 | prefixed ?: mount_table[k].what, |
60e76d48 ZJS |
675 | where, |
676 | mount_table[k].type, | |
677 | mount_table[k].flags, | |
678 | o); | |
4f086aab | 679 | if (r < 0 && fatal) |
60e76d48 | 680 | return r; |
e83bebef LP |
681 | } |
682 | ||
683 | return 0; | |
684 | } | |
685 | ||
a11fd406 ILG |
686 | static int parse_mount_bind_options(const char *options, unsigned long *mount_flags, char **mount_opts) { |
687 | const char *p = options; | |
688 | unsigned long flags = *mount_flags; | |
689 | char *opts = NULL; | |
690 | int r; | |
691 | ||
692 | assert(options); | |
693 | ||
694 | for (;;) { | |
695 | _cleanup_free_ char *word = NULL; | |
696 | ||
697 | r = extract_first_word(&p, &word, ",", 0); | |
698 | if (r < 0) | |
699 | return log_error_errno(r, "Failed to extract mount option: %m"); | |
700 | if (r == 0) | |
701 | break; | |
702 | ||
703 | if (streq(word, "rbind")) | |
704 | flags |= MS_REC; | |
705 | else if (streq(word, "norbind")) | |
706 | flags &= ~MS_REC; | |
707 | else { | |
38288f0b FS |
708 | return log_error_errno(SYNTHETIC_ERRNO(EINVAL), |
709 | "Invalid bind mount option: %s", | |
710 | word); | |
a11fd406 ILG |
711 | } |
712 | } | |
713 | ||
714 | *mount_flags = flags; | |
715 | /* in the future mount_opts will hold string options for mount(2) */ | |
716 | *mount_opts = opts; | |
717 | ||
718 | return 0; | |
719 | } | |
720 | ||
e83bebef | 721 | static int mount_bind(const char *dest, CustomMount *m) { |
a11fd406 ILG |
722 | _cleanup_free_ char *mount_opts = NULL, *where = NULL; |
723 | unsigned long mount_flags = MS_BIND | MS_REC; | |
68cf43c3 | 724 | struct stat source_st, dest_st; |
e83bebef LP |
725 | int r; |
726 | ||
86c0dd4a | 727 | assert(dest); |
e83bebef LP |
728 | assert(m); |
729 | ||
a11fd406 ILG |
730 | if (m->options) { |
731 | r = parse_mount_bind_options(m->options, &mount_flags, &mount_opts); | |
732 | if (r < 0) | |
733 | return r; | |
734 | } | |
735 | ||
e83bebef LP |
736 | if (stat(m->source, &source_st) < 0) |
737 | return log_error_errno(errno, "Failed to stat %s: %m", m->source); | |
738 | ||
a5648b80 | 739 | r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); |
68cf43c3 | 740 | if (r < 0) |
ec57bd42 | 741 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); |
8ce48cf0 LP |
742 | if (r > 0) { /* Path exists already? */ |
743 | ||
744 | if (stat(where, &dest_st) < 0) | |
745 | return log_error_errno(errno, "Failed to stat %s: %m", where); | |
e83bebef | 746 | |
baaa35ad ZJS |
747 | if (S_ISDIR(source_st.st_mode) && !S_ISDIR(dest_st.st_mode)) |
748 | return log_error_errno(SYNTHETIC_ERRNO(EINVAL), | |
749 | "Cannot bind mount directory %s on file %s.", | |
750 | m->source, where); | |
751 | ||
752 | if (!S_ISDIR(source_st.st_mode) && S_ISDIR(dest_st.st_mode)) | |
753 | return log_error_errno(SYNTHETIC_ERRNO(EINVAL), | |
754 | "Cannot bind mount file %s on directory %s.", | |
755 | m->source, where); | |
e83bebef | 756 | |
8ce48cf0 | 757 | } else { /* Path doesn't exist yet? */ |
e83bebef LP |
758 | r = mkdir_parents_label(where, 0755); |
759 | if (r < 0) | |
760 | return log_error_errno(r, "Failed to make parents of %s: %m", where); | |
b97e83cb BN |
761 | |
762 | /* Create the mount point. Any non-directory file can be | |
763 | * mounted on any non-directory file (regular, fifo, socket, | |
764 | * char, block). | |
765 | */ | |
766 | if (S_ISDIR(source_st.st_mode)) | |
767 | r = mkdir_label(where, 0755); | |
768 | else | |
769 | r = touch(where); | |
770 | if (r < 0) | |
771 | return log_error_errno(r, "Failed to create mount point %s: %m", where); | |
8ce48cf0 | 772 | } |
e83bebef | 773 | |
a11fd406 | 774 | r = mount_verbose(LOG_ERR, m->source, where, NULL, mount_flags, mount_opts); |
60e76d48 ZJS |
775 | if (r < 0) |
776 | return r; | |
e83bebef LP |
777 | |
778 | if (m->read_only) { | |
64e82c19 | 779 | r = bind_remount_recursive(where, MS_RDONLY, MS_RDONLY, NULL); |
e83bebef LP |
780 | if (r < 0) |
781 | return log_error_errno(r, "Read-only bind mount failed: %m"); | |
782 | } | |
783 | ||
784 | return 0; | |
785 | } | |
786 | ||
e091a5df | 787 | static int mount_tmpfs(const char *dest, CustomMount *m, uid_t uid_shift, const char *selinux_apifs_context) { |
e83bebef | 788 | |
68cf43c3 LP |
789 | const char *options; |
790 | _cleanup_free_ char *buf = NULL, *where = NULL; | |
e83bebef LP |
791 | int r; |
792 | ||
793 | assert(dest); | |
794 | assert(m); | |
795 | ||
a5648b80 | 796 | r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); |
68cf43c3 | 797 | if (r < 0) |
ec57bd42 | 798 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); |
8ce48cf0 LP |
799 | if (r == 0) { /* Doesn't exist yet? */ |
800 | r = mkdir_p_label(where, 0755); | |
801 | if (r < 0) | |
802 | return log_error_errno(r, "Creating mount point for tmpfs %s failed: %m", where); | |
803 | } | |
e83bebef | 804 | |
2fa017f1 | 805 | r = tmpfs_patch_options(m->options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); |
e83bebef LP |
806 | if (r < 0) |
807 | return log_oom(); | |
808 | options = r > 0 ? buf : m->options; | |
809 | ||
60e76d48 | 810 | return mount_verbose(LOG_ERR, "tmpfs", where, "tmpfs", MS_NODEV|MS_STRICTATIME, options); |
e83bebef LP |
811 | } |
812 | ||
86c0dd4a | 813 | static char *joined_and_escaped_lower_dirs(char **lower) { |
e83bebef LP |
814 | _cleanup_strv_free_ char **sv = NULL; |
815 | ||
816 | sv = strv_copy(lower); | |
817 | if (!sv) | |
818 | return NULL; | |
819 | ||
820 | strv_reverse(sv); | |
821 | ||
822 | if (!strv_shell_escape(sv, ",:")) | |
823 | return NULL; | |
824 | ||
825 | return strv_join(sv, ":"); | |
826 | } | |
827 | ||
828 | static int mount_overlay(const char *dest, CustomMount *m) { | |
86c0dd4a | 829 | _cleanup_free_ char *lower = NULL, *where = NULL, *escaped_source = NULL; |
68cf43c3 | 830 | const char *options; |
e83bebef LP |
831 | int r; |
832 | ||
833 | assert(dest); | |
834 | assert(m); | |
835 | ||
a5648b80 | 836 | r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); |
68cf43c3 | 837 | if (r < 0) |
ec57bd42 | 838 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); |
8ce48cf0 LP |
839 | if (r == 0) { /* Doesn't exist yet? */ |
840 | r = mkdir_label(where, 0755); | |
841 | if (r < 0) | |
842 | return log_error_errno(r, "Creating mount point for overlay %s failed: %m", where); | |
843 | } | |
e83bebef LP |
844 | |
845 | (void) mkdir_p_label(m->source, 0755); | |
846 | ||
847 | lower = joined_and_escaped_lower_dirs(m->lower); | |
848 | if (!lower) | |
849 | return log_oom(); | |
850 | ||
86c0dd4a LP |
851 | escaped_source = shell_escape(m->source, ",:"); |
852 | if (!escaped_source) | |
853 | return log_oom(); | |
e83bebef | 854 | |
86c0dd4a | 855 | if (m->read_only) |
e83bebef | 856 | options = strjoina("lowerdir=", escaped_source, ":", lower); |
86c0dd4a LP |
857 | else { |
858 | _cleanup_free_ char *escaped_work_dir = NULL; | |
e83bebef | 859 | |
e83bebef LP |
860 | escaped_work_dir = shell_escape(m->work_dir, ",:"); |
861 | if (!escaped_work_dir) | |
862 | return log_oom(); | |
863 | ||
864 | options = strjoina("lowerdir=", lower, ",upperdir=", escaped_source, ",workdir=", escaped_work_dir); | |
865 | } | |
866 | ||
60e76d48 | 867 | return mount_verbose(LOG_ERR, "overlay", where, "overlay", m->read_only ? MS_RDONLY : 0, options); |
e83bebef LP |
868 | } |
869 | ||
de40a303 | 870 | static int mount_inaccessible(const char *dest, CustomMount *m) { |
e5f10caf | 871 | _cleanup_free_ char *where = NULL, *source = NULL; |
de40a303 LP |
872 | struct stat st; |
873 | int r; | |
874 | ||
875 | assert(dest); | |
876 | assert(m); | |
877 | ||
a5648b80 | 878 | r = chase_symlinks_and_stat(m->destination, dest, CHASE_PREFIX_ROOT, &where, &st, NULL); |
de40a303 LP |
879 | if (r < 0) { |
880 | log_full_errno(m->graceful ? LOG_DEBUG : LOG_ERR, r, "Failed to resolve %s/%s: %m", dest, m->destination); | |
881 | return m->graceful ? 0 : r; | |
882 | } | |
883 | ||
48b747fa | 884 | r = mode_to_inaccessible_node(NULL, st.st_mode, &source); |
e5f10caf AZ |
885 | if (r < 0) |
886 | return m->graceful ? 0 : r; | |
de40a303 LP |
887 | |
888 | r = mount_verbose(m->graceful ? LOG_DEBUG : LOG_ERR, source, where, NULL, MS_BIND, NULL); | |
889 | if (r < 0) | |
890 | return m->graceful ? 0 : r; | |
891 | ||
892 | r = mount_verbose(m->graceful ? LOG_DEBUG : LOG_ERR, NULL, where, NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, NULL); | |
2c9b7a7e | 893 | if (r < 0) { |
9610210d | 894 | (void) umount_verbose(where); |
de40a303 | 895 | return m->graceful ? 0 : r; |
2c9b7a7e | 896 | } |
de40a303 LP |
897 | |
898 | return 0; | |
899 | } | |
900 | ||
901 | static int mount_arbitrary(const char *dest, CustomMount *m) { | |
902 | _cleanup_free_ char *where = NULL; | |
903 | int r; | |
904 | ||
905 | assert(dest); | |
906 | assert(m); | |
907 | ||
a5648b80 | 908 | r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); |
de40a303 LP |
909 | if (r < 0) |
910 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); | |
911 | if (r == 0) { /* Doesn't exist yet? */ | |
912 | r = mkdir_p_label(where, 0755); | |
913 | if (r < 0) | |
914 | return log_error_errno(r, "Creating mount point for mount %s failed: %m", where); | |
915 | } | |
916 | ||
917 | return mount_verbose(LOG_ERR, m->source, where, m->type_argument, 0, m->options); | |
918 | } | |
919 | ||
e83bebef LP |
920 | int mount_custom( |
921 | const char *dest, | |
88614c8a | 922 | CustomMount *mounts, size_t n, |
e091a5df | 923 | uid_t uid_shift, |
de40a303 | 924 | const char *selinux_apifs_context, |
5f0a6347 | 925 | MountSettingsMask mount_settings) { |
e83bebef | 926 | |
88614c8a | 927 | size_t i; |
e83bebef LP |
928 | int r; |
929 | ||
930 | assert(dest); | |
931 | ||
932 | for (i = 0; i < n; i++) { | |
933 | CustomMount *m = mounts + i; | |
934 | ||
bd6609eb | 935 | if (FLAGS_SET(mount_settings, MOUNT_IN_USERNS) != m->in_userns) |
5f0a6347 DDM |
936 | continue; |
937 | ||
bd6609eb | 938 | if (FLAGS_SET(mount_settings, MOUNT_ROOT_ONLY) && !path_equal(m->destination, "/")) |
5f0a6347 DDM |
939 | continue; |
940 | ||
bd6609eb | 941 | if (FLAGS_SET(mount_settings, MOUNT_NON_ROOT_ONLY) && path_equal(m->destination, "/")) |
de40a303 LP |
942 | continue; |
943 | ||
e83bebef LP |
944 | switch (m->type) { |
945 | ||
946 | case CUSTOM_MOUNT_BIND: | |
947 | r = mount_bind(dest, m); | |
948 | break; | |
949 | ||
950 | case CUSTOM_MOUNT_TMPFS: | |
e091a5df | 951 | r = mount_tmpfs(dest, m, uid_shift, selinux_apifs_context); |
e83bebef LP |
952 | break; |
953 | ||
954 | case CUSTOM_MOUNT_OVERLAY: | |
955 | r = mount_overlay(dest, m); | |
956 | break; | |
957 | ||
de40a303 LP |
958 | case CUSTOM_MOUNT_INACCESSIBLE: |
959 | r = mount_inaccessible(dest, m); | |
960 | break; | |
961 | ||
962 | case CUSTOM_MOUNT_ARBITRARY: | |
963 | r = mount_arbitrary(dest, m); | |
964 | break; | |
965 | ||
e83bebef LP |
966 | default: |
967 | assert_not_reached("Unknown custom mount type"); | |
968 | } | |
969 | ||
970 | if (r < 0) | |
971 | return r; | |
972 | } | |
973 | ||
974 | return 0; | |
975 | } | |
976 | ||
bbd407ea DDM |
977 | bool has_custom_root_mount(const CustomMount *mounts, size_t n) { |
978 | size_t i; | |
979 | ||
980 | for (i = 0; i < n; i++) { | |
981 | const CustomMount *m = mounts + i; | |
982 | ||
983 | if (path_equal(m->destination, "/")) | |
984 | return true; | |
985 | } | |
986 | ||
987 | return false; | |
988 | } | |
989 | ||
e091a5df | 990 | static int setup_volatile_state(const char *directory, uid_t uid_shift, const char *selinux_apifs_context) { |
e83bebef LP |
991 | |
992 | _cleanup_free_ char *buf = NULL; | |
993 | const char *p, *options; | |
994 | int r; | |
995 | ||
996 | assert(directory); | |
997 | ||
e5b43a04 | 998 | /* --volatile=state means we simply overmount /var with a tmpfs, and the rest read-only. */ |
e83bebef | 999 | |
64e82c19 | 1000 | r = bind_remount_recursive(directory, MS_RDONLY, MS_RDONLY, NULL); |
e83bebef LP |
1001 | if (r < 0) |
1002 | return log_error_errno(r, "Failed to remount %s read-only: %m", directory); | |
1003 | ||
1004 | p = prefix_roota(directory, "/var"); | |
1005 | r = mkdir(p, 0755); | |
1006 | if (r < 0 && errno != EEXIST) | |
1007 | return log_error_errno(errno, "Failed to create %s: %m", directory); | |
1008 | ||
7d85383e | 1009 | options = "mode=755" TMPFS_LIMITS_VOLATILE_STATE; |
2fa017f1 | 1010 | r = tmpfs_patch_options(options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); |
e83bebef LP |
1011 | if (r < 0) |
1012 | return log_oom(); | |
1013 | if (r > 0) | |
1014 | options = buf; | |
1015 | ||
60e76d48 | 1016 | return mount_verbose(LOG_ERR, "tmpfs", p, "tmpfs", MS_STRICTATIME, options); |
e83bebef LP |
1017 | } |
1018 | ||
e091a5df | 1019 | static int setup_volatile_yes(const char *directory, uid_t uid_shift, const char *selinux_apifs_context) { |
e83bebef LP |
1020 | |
1021 | bool tmpfs_mounted = false, bind_mounted = false; | |
1022 | char template[] = "/tmp/nspawn-volatile-XXXXXX"; | |
07b9f3f0 | 1023 | _cleanup_free_ char *buf = NULL, *bindir = NULL; |
e83bebef | 1024 | const char *f, *t, *options; |
07b9f3f0 | 1025 | struct stat st; |
e83bebef LP |
1026 | int r; |
1027 | ||
1028 | assert(directory); | |
1029 | ||
07b9f3f0 LP |
1030 | /* --volatile=yes means we mount a tmpfs to the root dir, and the original /usr to use inside it, and |
1031 | * that read-only. Before we start setting this up let's validate if the image has the /usr merge | |
1032 | * implemented, and let's output a friendly log message if it hasn't. */ | |
1033 | ||
1034 | bindir = path_join(directory, "/bin"); | |
1035 | if (!bindir) | |
1036 | return log_oom(); | |
1037 | if (lstat(bindir, &st) < 0) { | |
1038 | if (errno != ENOENT) | |
1039 | return log_error_errno(errno, "Failed to stat /bin directory below image: %m"); | |
1040 | ||
1041 | /* ENOENT is fine, just means the image is probably just a naked /usr and we can create the | |
1042 | * rest. */ | |
1043 | } else if (S_ISDIR(st.st_mode)) | |
1044 | return log_error_errno(SYNTHETIC_ERRNO(EISDIR), | |
1045 | "Sorry, --volatile=yes mode is not supported with OS images that have not merged /bin/, /sbin/, /lib/, /lib64/ into /usr/. " | |
1046 | "Please work with your distribution and help them adopt the merged /usr scheme."); | |
1047 | else if (!S_ISLNK(st.st_mode)) | |
1048 | return log_error_errno(SYNTHETIC_ERRNO(EINVAL), | |
1049 | "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 |
1050 | |
1051 | if (!mkdtemp(template)) | |
1052 | return log_error_errno(errno, "Failed to create temporary directory: %m"); | |
1053 | ||
7d85383e | 1054 | options = "mode=755" TMPFS_LIMITS_ROOTFS; |
2fa017f1 | 1055 | r = tmpfs_patch_options(options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); |
e83bebef | 1056 | if (r < 0) |
c55d0ae7 | 1057 | goto fail; |
e83bebef LP |
1058 | if (r > 0) |
1059 | options = buf; | |
1060 | ||
60e76d48 ZJS |
1061 | r = mount_verbose(LOG_ERR, "tmpfs", template, "tmpfs", MS_STRICTATIME, options); |
1062 | if (r < 0) | |
e83bebef | 1063 | goto fail; |
e83bebef LP |
1064 | |
1065 | tmpfs_mounted = true; | |
1066 | ||
1067 | f = prefix_roota(directory, "/usr"); | |
1068 | t = prefix_roota(template, "/usr"); | |
1069 | ||
1070 | r = mkdir(t, 0755); | |
1071 | if (r < 0 && errno != EEXIST) { | |
1072 | r = log_error_errno(errno, "Failed to create %s: %m", t); | |
1073 | goto fail; | |
1074 | } | |
1075 | ||
60e76d48 ZJS |
1076 | r = mount_verbose(LOG_ERR, f, t, NULL, MS_BIND|MS_REC, NULL); |
1077 | if (r < 0) | |
e83bebef | 1078 | goto fail; |
e83bebef LP |
1079 | |
1080 | bind_mounted = true; | |
1081 | ||
64e82c19 | 1082 | r = bind_remount_recursive(t, MS_RDONLY, MS_RDONLY, NULL); |
e83bebef LP |
1083 | if (r < 0) { |
1084 | log_error_errno(r, "Failed to remount %s read-only: %m", t); | |
1085 | goto fail; | |
1086 | } | |
1087 | ||
60e76d48 ZJS |
1088 | r = mount_verbose(LOG_ERR, template, directory, NULL, MS_MOVE, NULL); |
1089 | if (r < 0) | |
e83bebef | 1090 | goto fail; |
e83bebef LP |
1091 | |
1092 | (void) rmdir(template); | |
1093 | ||
1094 | return 0; | |
1095 | ||
1096 | fail: | |
1097 | if (bind_mounted) | |
60e76d48 | 1098 | (void) umount_verbose(t); |
e83bebef LP |
1099 | |
1100 | if (tmpfs_mounted) | |
60e76d48 | 1101 | (void) umount_verbose(template); |
e83bebef LP |
1102 | (void) rmdir(template); |
1103 | return r; | |
1104 | } | |
b53ede69 | 1105 | |
e091a5df | 1106 | static int setup_volatile_overlay(const char *directory, uid_t uid_shift, const char *selinux_apifs_context) { |
6c610aca LP |
1107 | |
1108 | _cleanup_free_ char *buf = NULL, *escaped_directory = NULL, *escaped_upper = NULL, *escaped_work = NULL; | |
1109 | char template[] = "/tmp/nspawn-volatile-XXXXXX"; | |
1110 | const char *upper, *work, *options; | |
1111 | bool tmpfs_mounted = false; | |
1112 | int r; | |
1113 | ||
1114 | assert(directory); | |
1115 | ||
1116 | /* --volatile=overlay means we mount an overlayfs to the root dir. */ | |
1117 | ||
1118 | if (!mkdtemp(template)) | |
1119 | return log_error_errno(errno, "Failed to create temporary directory: %m"); | |
1120 | ||
7d85383e | 1121 | options = "mode=755" TMPFS_LIMITS_ROOTFS; |
6c610aca LP |
1122 | r = tmpfs_patch_options(options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); |
1123 | if (r < 0) | |
1124 | goto finish; | |
1125 | if (r > 0) | |
1126 | options = buf; | |
1127 | ||
1128 | r = mount_verbose(LOG_ERR, "tmpfs", template, "tmpfs", MS_STRICTATIME, options); | |
1129 | if (r < 0) | |
1130 | goto finish; | |
1131 | ||
1132 | tmpfs_mounted = true; | |
1133 | ||
1134 | upper = strjoina(template, "/upper"); | |
1135 | work = strjoina(template, "/work"); | |
1136 | ||
1137 | if (mkdir(upper, 0755) < 0) { | |
1138 | r = log_error_errno(errno, "Failed to create %s: %m", upper); | |
1139 | goto finish; | |
1140 | } | |
1141 | if (mkdir(work, 0755) < 0) { | |
1142 | r = log_error_errno(errno, "Failed to create %s: %m", work); | |
1143 | goto finish; | |
1144 | } | |
1145 | ||
1146 | /* And now, let's overmount the root dir with an overlayfs that uses the root dir as lower dir. It's kinda nice | |
1147 | * that the kernel allows us to do that without going through some mount point rearrangements. */ | |
1148 | ||
1149 | escaped_directory = shell_escape(directory, ",:"); | |
1150 | escaped_upper = shell_escape(upper, ",:"); | |
1151 | escaped_work = shell_escape(work, ",:"); | |
1152 | if (!escaped_directory || !escaped_upper || !escaped_work) { | |
1153 | r = -ENOMEM; | |
1154 | goto finish; | |
1155 | } | |
1156 | ||
1157 | options = strjoina("lowerdir=", escaped_directory, ",upperdir=", escaped_upper, ",workdir=", escaped_work); | |
1158 | r = mount_verbose(LOG_ERR, "overlay", directory, "overlay", 0, options); | |
1159 | ||
1160 | finish: | |
1161 | if (tmpfs_mounted) | |
1162 | (void) umount_verbose(template); | |
1163 | ||
1164 | (void) rmdir(template); | |
1165 | return r; | |
1166 | } | |
1167 | ||
e5b43a04 LP |
1168 | int setup_volatile_mode( |
1169 | const char *directory, | |
1170 | VolatileMode mode, | |
e091a5df | 1171 | uid_t uid_shift, |
e5b43a04 LP |
1172 | const char *selinux_apifs_context) { |
1173 | ||
1174 | switch (mode) { | |
1175 | ||
1176 | case VOLATILE_YES: | |
e091a5df | 1177 | return setup_volatile_yes(directory, uid_shift, selinux_apifs_context); |
e5b43a04 LP |
1178 | |
1179 | case VOLATILE_STATE: | |
e091a5df | 1180 | return setup_volatile_state(directory, uid_shift, selinux_apifs_context); |
e5b43a04 | 1181 | |
6c610aca | 1182 | case VOLATILE_OVERLAY: |
e091a5df | 1183 | return setup_volatile_overlay(directory, uid_shift, selinux_apifs_context); |
6c610aca | 1184 | |
e5b43a04 LP |
1185 | default: |
1186 | return 0; | |
1187 | } | |
1188 | } | |
1189 | ||
b53ede69 PW |
1190 | /* Expects *pivot_root_new and *pivot_root_old to be initialised to allocated memory or NULL. */ |
1191 | int pivot_root_parse(char **pivot_root_new, char **pivot_root_old, const char *s) { | |
1192 | _cleanup_free_ char *root_new = NULL, *root_old = NULL; | |
1193 | const char *p = s; | |
1194 | int r; | |
1195 | ||
1196 | assert(pivot_root_new); | |
1197 | assert(pivot_root_old); | |
1198 | ||
1199 | r = extract_first_word(&p, &root_new, ":", EXTRACT_DONT_COALESCE_SEPARATORS); | |
1200 | if (r < 0) | |
1201 | return r; | |
1202 | if (r == 0) | |
1203 | return -EINVAL; | |
1204 | ||
1205 | if (isempty(p)) | |
1206 | root_old = NULL; | |
1207 | else { | |
1208 | root_old = strdup(p); | |
1209 | if (!root_old) | |
1210 | return -ENOMEM; | |
1211 | } | |
1212 | ||
1213 | if (!path_is_absolute(root_new)) | |
1214 | return -EINVAL; | |
1215 | if (root_old && !path_is_absolute(root_old)) | |
1216 | return -EINVAL; | |
1217 | ||
1218 | free_and_replace(*pivot_root_new, root_new); | |
1219 | free_and_replace(*pivot_root_old, root_old); | |
1220 | ||
1221 | return 0; | |
1222 | } | |
1223 | ||
1224 | int setup_pivot_root(const char *directory, const char *pivot_root_new, const char *pivot_root_old) { | |
1225 | _cleanup_free_ char *directory_pivot_root_new = NULL; | |
1226 | _cleanup_free_ char *pivot_tmp_pivot_root_old = NULL; | |
1227 | char pivot_tmp[] = "/tmp/nspawn-pivot-XXXXXX"; | |
1228 | bool remove_pivot_tmp = false; | |
1229 | int r; | |
1230 | ||
1231 | assert(directory); | |
1232 | ||
1233 | if (!pivot_root_new) | |
1234 | return 0; | |
1235 | ||
1236 | /* Pivot pivot_root_new to / and the existing / to pivot_root_old. | |
1237 | * If pivot_root_old is NULL, the existing / disappears. | |
1238 | * This requires a temporary directory, pivot_tmp, which is | |
1239 | * not a child of either. | |
1240 | * | |
1241 | * This is typically used for OSTree-style containers, where | |
1242 | * the root partition contains several sysroots which could be | |
1243 | * run. Normally, one would be chosen by the bootloader and | |
1244 | * pivoted to / by initramfs. | |
1245 | * | |
1246 | * For example, for an OSTree deployment, pivot_root_new | |
1247 | * would be: /ostree/deploy/$os/deploy/$checksum. Note that this | |
1248 | * code doesn’t do the /var mount which OSTree expects: use | |
1249 | * --bind +/sysroot/ostree/deploy/$os/var:/var for that. | |
1250 | * | |
1251 | * So in the OSTree case, we’ll end up with something like: | |
1252 | * - directory = /tmp/nspawn-root-123456 | |
1253 | * - pivot_root_new = /ostree/deploy/os/deploy/123abc | |
1254 | * - pivot_root_old = /sysroot | |
1255 | * - directory_pivot_root_new = | |
1256 | * /tmp/nspawn-root-123456/ostree/deploy/os/deploy/123abc | |
1257 | * - pivot_tmp = /tmp/nspawn-pivot-123456 | |
1258 | * - pivot_tmp_pivot_root_old = /tmp/nspawn-pivot-123456/sysroot | |
1259 | * | |
1260 | * Requires all file systems at directory and below to be mounted | |
1261 | * MS_PRIVATE or MS_SLAVE so they can be moved. | |
1262 | */ | |
c6134d3e LP |
1263 | directory_pivot_root_new = path_join(directory, pivot_root_new); |
1264 | if (!directory_pivot_root_new) | |
1265 | return log_oom(); | |
b53ede69 PW |
1266 | |
1267 | /* Remount directory_pivot_root_new to make it movable. */ | |
1268 | r = mount_verbose(LOG_ERR, directory_pivot_root_new, directory_pivot_root_new, NULL, MS_BIND, NULL); | |
1269 | if (r < 0) | |
1270 | goto done; | |
1271 | ||
1272 | if (pivot_root_old) { | |
1273 | if (!mkdtemp(pivot_tmp)) { | |
1274 | r = log_error_errno(errno, "Failed to create temporary directory: %m"); | |
1275 | goto done; | |
1276 | } | |
1277 | ||
1278 | remove_pivot_tmp = true; | |
c6134d3e LP |
1279 | pivot_tmp_pivot_root_old = path_join(pivot_tmp, pivot_root_old); |
1280 | if (!pivot_tmp_pivot_root_old) { | |
1281 | r = log_oom(); | |
1282 | goto done; | |
1283 | } | |
b53ede69 PW |
1284 | |
1285 | r = mount_verbose(LOG_ERR, directory_pivot_root_new, pivot_tmp, NULL, MS_MOVE, NULL); | |
1286 | if (r < 0) | |
1287 | goto done; | |
1288 | ||
1289 | r = mount_verbose(LOG_ERR, directory, pivot_tmp_pivot_root_old, NULL, MS_MOVE, NULL); | |
1290 | if (r < 0) | |
1291 | goto done; | |
1292 | ||
1293 | r = mount_verbose(LOG_ERR, pivot_tmp, directory, NULL, MS_MOVE, NULL); | |
1294 | if (r < 0) | |
1295 | goto done; | |
1296 | } else { | |
1297 | r = mount_verbose(LOG_ERR, directory_pivot_root_new, directory, NULL, MS_MOVE, NULL); | |
1298 | if (r < 0) | |
1299 | goto done; | |
1300 | } | |
1301 | ||
1302 | done: | |
1303 | if (remove_pivot_tmp) | |
1304 | (void) rmdir(pivot_tmp); | |
1305 | ||
1306 | return r; | |
1307 | } |