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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" |
35cd0ba5 | 13 | #include "mkdir-label.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) { | |
86c0dd4a LP |
169 | STRV_FOREACH(j, m->lower) { |
170 | char *s; | |
171 | ||
172 | s = resolve_source_path(dest, *j); | |
173 | if (!s) | |
174 | return log_oom(); | |
175 | ||
10af01a5 | 176 | free_and_replace(*j, s); |
86c0dd4a LP |
177 | } |
178 | ||
d0556c55 LP |
179 | if (m->source) { |
180 | char *s; | |
181 | ||
182 | s = resolve_source_path(dest, m->source); | |
183 | if (!s) | |
184 | return log_oom(); | |
185 | ||
186 | free_and_replace(m->source, s); | |
187 | } else { | |
188 | r = allocate_temporary_source(m); | |
189 | if (r < 0) | |
190 | return r; | |
191 | } | |
192 | ||
86c0dd4a LP |
193 | if (m->work_dir) { |
194 | char *s; | |
195 | ||
196 | s = resolve_source_path(dest, m->work_dir); | |
197 | if (!s) | |
198 | return log_oom(); | |
199 | ||
10af01a5 | 200 | free_and_replace(m->work_dir, s); |
86c0dd4a | 201 | } else { |
86c0dd4a LP |
202 | r = tempfn_random(m->source, NULL, &m->work_dir); |
203 | if (r < 0) | |
204 | return log_error_errno(r, "Failed to acquire working directory: %m"); | |
205 | } | |
206 | ||
207 | (void) mkdir_label(m->work_dir, 0700); | |
208 | } | |
209 | } | |
210 | ||
211 | return 0; | |
212 | } | |
213 | ||
88614c8a | 214 | int bind_mount_parse(CustomMount **l, size_t *n, const char *s, bool read_only) { |
e83bebef LP |
215 | _cleanup_free_ char *source = NULL, *destination = NULL, *opts = NULL; |
216 | const char *p = s; | |
217 | CustomMount *m; | |
218 | int r; | |
219 | ||
220 | assert(l); | |
221 | assert(n); | |
222 | ||
223 | r = extract_many_words(&p, ":", EXTRACT_DONT_COALESCE_SEPARATORS, &source, &destination, NULL); | |
224 | if (r < 0) | |
225 | return r; | |
226 | if (r == 0) | |
227 | return -EINVAL; | |
e83bebef | 228 | if (r == 1) { |
86c0dd4a | 229 | destination = strdup(source[0] == '+' ? source+1 : source); |
e83bebef LP |
230 | if (!destination) |
231 | return -ENOMEM; | |
232 | } | |
e83bebef LP |
233 | if (r == 2 && !isempty(p)) { |
234 | opts = strdup(p); | |
235 | if (!opts) | |
236 | return -ENOMEM; | |
237 | } | |
238 | ||
c7a4890c | 239 | if (isempty(source)) |
0e636bf5 | 240 | source = mfree(source); |
c7a4890c | 241 | else if (!source_path_is_valid(source)) |
e83bebef | 242 | return -EINVAL; |
c7a4890c | 243 | |
e83bebef LP |
244 | if (!path_is_absolute(destination)) |
245 | return -EINVAL; | |
246 | ||
247 | m = custom_mount_add(l, n, CUSTOM_MOUNT_BIND); | |
248 | if (!m) | |
48cbe5f8 | 249 | return -ENOMEM; |
e83bebef | 250 | |
0e636bf5 ZJS |
251 | m->source = TAKE_PTR(source); |
252 | m->destination = TAKE_PTR(destination); | |
e83bebef | 253 | m->read_only = read_only; |
0e636bf5 | 254 | m->options = TAKE_PTR(opts); |
de40a303 | 255 | |
e83bebef LP |
256 | return 0; |
257 | } | |
258 | ||
88614c8a | 259 | int tmpfs_mount_parse(CustomMount **l, size_t *n, const char *s) { |
e83bebef LP |
260 | _cleanup_free_ char *path = NULL, *opts = NULL; |
261 | const char *p = s; | |
262 | CustomMount *m; | |
263 | int r; | |
264 | ||
265 | assert(l); | |
266 | assert(n); | |
267 | assert(s); | |
268 | ||
269 | r = extract_first_word(&p, &path, ":", EXTRACT_DONT_COALESCE_SEPARATORS); | |
270 | if (r < 0) | |
271 | return r; | |
272 | if (r == 0) | |
273 | return -EINVAL; | |
274 | ||
275 | if (isempty(p)) | |
276 | opts = strdup("mode=0755"); | |
277 | else | |
278 | opts = strdup(p); | |
279 | if (!opts) | |
280 | return -ENOMEM; | |
281 | ||
282 | if (!path_is_absolute(path)) | |
283 | return -EINVAL; | |
284 | ||
285 | m = custom_mount_add(l, n, CUSTOM_MOUNT_TMPFS); | |
286 | if (!m) | |
287 | return -ENOMEM; | |
288 | ||
1cc6c93a YW |
289 | m->destination = TAKE_PTR(path); |
290 | m->options = TAKE_PTR(opts); | |
e83bebef | 291 | |
e83bebef LP |
292 | return 0; |
293 | } | |
294 | ||
88614c8a | 295 | int overlay_mount_parse(CustomMount **l, size_t *n, const char *s, bool read_only) { |
ad85779a LP |
296 | _cleanup_free_ char *upper = NULL, *destination = NULL; |
297 | _cleanup_strv_free_ char **lower = NULL; | |
298 | CustomMount *m; | |
86c0dd4a | 299 | int k; |
ad85779a | 300 | |
90e30d76 | 301 | k = strv_split_full(&lower, s, ":", EXTRACT_DONT_COALESCE_SEPARATORS); |
86c0dd4a LP |
302 | if (k < 0) |
303 | return k; | |
ad85779a LP |
304 | if (k < 2) |
305 | return -EADDRNOTAVAIL; | |
306 | if (k == 2) { | |
86c0dd4a LP |
307 | /* If two parameters are specified, the first one is the lower, the second one the upper directory. And |
308 | * we'll also define the destination mount point the same as the upper. */ | |
309 | ||
310 | if (!source_path_is_valid(lower[0]) || | |
311 | !source_path_is_valid(lower[1])) | |
312 | return -EINVAL; | |
313 | ||
ae2a15bc | 314 | upper = TAKE_PTR(lower[1]); |
ad85779a | 315 | |
86c0dd4a | 316 | destination = strdup(upper[0] == '+' ? upper+1 : upper); /* take the destination without "+" prefix */ |
ad85779a LP |
317 | if (!destination) |
318 | return -ENOMEM; | |
ad85779a | 319 | } else { |
86c0dd4a LP |
320 | /* If more than two parameters are specified, the last one is the destination, the second to last one |
321 | * the "upper", and all before that the "lower" directories. */ | |
322 | ||
ad85779a | 323 | destination = lower[k - 1]; |
ae2a15bc | 324 | upper = TAKE_PTR(lower[k - 2]); |
86c0dd4a | 325 | |
c7a4890c LP |
326 | STRV_FOREACH(i, lower) |
327 | if (!source_path_is_valid(*i)) | |
328 | return -EINVAL; | |
329 | ||
330 | /* If the upper directory is unspecified, then let's create it automatically as a throw-away directory | |
331 | * in /var/tmp */ | |
332 | if (isempty(upper)) | |
1d0c1146 | 333 | upper = mfree(upper); |
c7a4890c LP |
334 | else if (!source_path_is_valid(upper)) |
335 | return -EINVAL; | |
336 | ||
86c0dd4a LP |
337 | if (!path_is_absolute(destination)) |
338 | return -EINVAL; | |
ad85779a LP |
339 | } |
340 | ||
341 | m = custom_mount_add(l, n, CUSTOM_MOUNT_OVERLAY); | |
342 | if (!m) | |
343 | return -ENOMEM; | |
344 | ||
1cc6c93a YW |
345 | m->destination = TAKE_PTR(destination); |
346 | m->source = TAKE_PTR(upper); | |
347 | m->lower = TAKE_PTR(lower); | |
ad85779a LP |
348 | m->read_only = read_only; |
349 | ||
ad85779a LP |
350 | return 0; |
351 | } | |
352 | ||
de40a303 LP |
353 | int inaccessible_mount_parse(CustomMount **l, size_t *n, const char *s) { |
354 | _cleanup_free_ char *path = NULL; | |
355 | CustomMount *m; | |
356 | ||
357 | assert(l); | |
358 | assert(n); | |
359 | assert(s); | |
360 | ||
361 | if (!path_is_absolute(s)) | |
362 | return -EINVAL; | |
363 | ||
364 | path = strdup(s); | |
365 | if (!path) | |
366 | return -ENOMEM; | |
367 | ||
368 | m = custom_mount_add(l, n, CUSTOM_MOUNT_INACCESSIBLE); | |
369 | if (!m) | |
370 | return -ENOMEM; | |
371 | ||
372 | m->destination = TAKE_PTR(path); | |
373 | return 0; | |
374 | } | |
375 | ||
04029482 | 376 | int tmpfs_patch_options( |
e83bebef | 377 | const char *options, |
2fa017f1 | 378 | uid_t uid_shift, |
e83bebef LP |
379 | const char *selinux_apifs_context, |
380 | char **ret) { | |
381 | ||
cfea7618 | 382 | _cleanup_free_ char *buf = NULL; |
e83bebef | 383 | |
cfea7618 | 384 | assert(ret); |
e83bebef | 385 | |
cfea7618 YW |
386 | if (options) { |
387 | buf = strdup(options); | |
388 | if (!buf) | |
389 | return -ENOMEM; | |
e83bebef LP |
390 | } |
391 | ||
cfea7618 YW |
392 | if (uid_shift != UID_INVALID) |
393 | if (strextendf_with_separator(&buf, ",", "uid=" UID_FMT ",gid=" UID_FMT, uid_shift, uid_shift) < 0) | |
e83bebef | 394 | return -ENOMEM; |
e83bebef | 395 | |
cfea7618 YW |
396 | #if HAVE_SELINUX |
397 | if (selinux_apifs_context) | |
d3d15594 | 398 | if (strextendf_with_separator(&buf, ",", "context=\"%s\"", selinux_apifs_context) < 0) |
0996ef00 | 399 | return -ENOMEM; |
cfea7618 | 400 | #endif |
0996ef00 | 401 | |
cfea7618 YW |
402 | *ret = TAKE_PTR(buf); |
403 | return !!*ret; | |
e83bebef LP |
404 | } |
405 | ||
4f086aab | 406 | int mount_sysfs(const char *dest, MountSettingsMask mount_settings) { |
d8fc6a00 | 407 | const char *full, *top, *x; |
d1678248 | 408 | int r; |
4f086aab | 409 | unsigned long extra_flags = 0; |
d8fc6a00 LP |
410 | |
411 | top = prefix_roota(dest, "/sys"); | |
40fd52f2 | 412 | r = path_is_fs_type(top, SYSFS_MAGIC); |
d1678248 ILG |
413 | if (r < 0) |
414 | return log_error_errno(r, "Failed to determine filesystem type of %s: %m", top); | |
415 | /* /sys might already be mounted as sysfs by the outer child in the | |
416 | * !netns case. In this case, it's all good. Don't touch it because we | |
417 | * don't have the right to do so, see https://github.com/systemd/systemd/issues/1555. | |
418 | */ | |
419 | if (r > 0) | |
420 | return 0; | |
421 | ||
d8fc6a00 LP |
422 | full = prefix_roota(top, "/full"); |
423 | ||
424 | (void) mkdir(full, 0755); | |
425 | ||
bd6609eb | 426 | if (FLAGS_SET(mount_settings, MOUNT_APPLY_APIVFS_RO)) |
4f086aab SU |
427 | extra_flags |= MS_RDONLY; |
428 | ||
511a8cfe LP |
429 | r = mount_nofollow_verbose(LOG_ERR, "sysfs", full, "sysfs", |
430 | MS_NOSUID|MS_NOEXEC|MS_NODEV|extra_flags, NULL); | |
60e76d48 ZJS |
431 | if (r < 0) |
432 | return r; | |
d8fc6a00 LP |
433 | |
434 | FOREACH_STRING(x, "block", "bus", "class", "dev", "devices", "kernel") { | |
435 | _cleanup_free_ char *from = NULL, *to = NULL; | |
436 | ||
c6134d3e | 437 | from = path_join(full, x); |
d8fc6a00 LP |
438 | if (!from) |
439 | return log_oom(); | |
440 | ||
c6134d3e | 441 | to = path_join(top, x); |
d8fc6a00 LP |
442 | if (!to) |
443 | return log_oom(); | |
444 | ||
445 | (void) mkdir(to, 0755); | |
446 | ||
511a8cfe | 447 | r = mount_nofollow_verbose(LOG_ERR, from, to, NULL, MS_BIND, NULL); |
60e76d48 ZJS |
448 | if (r < 0) |
449 | return r; | |
d8fc6a00 | 450 | |
511a8cfe LP |
451 | r = mount_nofollow_verbose(LOG_ERR, NULL, to, NULL, |
452 | MS_BIND|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT|extra_flags, NULL); | |
60e76d48 ZJS |
453 | if (r < 0) |
454 | return r; | |
d8fc6a00 LP |
455 | } |
456 | ||
30f5d104 | 457 | r = umount_verbose(LOG_ERR, full, UMOUNT_NOFOLLOW); |
60e76d48 ZJS |
458 | if (r < 0) |
459 | return r; | |
d8fc6a00 LP |
460 | |
461 | if (rmdir(full) < 0) | |
462 | return log_error_errno(errno, "Failed to remove %s: %m", full); | |
463 | ||
0996ef00 CB |
464 | /* Create mountpoint for cgroups. Otherwise we are not allowed since we |
465 | * remount /sys read-only. | |
466 | */ | |
677a72cd LS |
467 | x = prefix_roota(top, "/fs/cgroup"); |
468 | (void) mkdir_p(x, 0755); | |
d8fc6a00 | 469 | |
511a8cfe LP |
470 | return mount_nofollow_verbose(LOG_ERR, NULL, top, NULL, |
471 | MS_BIND|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT|extra_flags, NULL); | |
d8fc6a00 LP |
472 | } |
473 | ||
e83bebef | 474 | int mount_all(const char *dest, |
4f086aab | 475 | MountSettingsMask mount_settings, |
2fa017f1 | 476 | uid_t uid_shift, |
e83bebef LP |
477 | const char *selinux_apifs_context) { |
478 | ||
de40a303 LP |
479 | #define PROC_INACCESSIBLE_REG(path) \ |
480 | { "/run/systemd/inaccessible/reg", (path), NULL, NULL, MS_BIND, \ | |
481 | MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* Bind mount first ... */ \ | |
d4b653c5 LP |
482 | { NULL, (path), NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, \ |
483 | MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO } /* Then, make it r/o */ | |
484 | ||
485 | #define PROC_READ_ONLY(path) \ | |
486 | { (path), (path), NULL, NULL, MS_BIND, \ | |
487 | MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* Bind mount first ... */ \ | |
488 | { NULL, (path), NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, \ | |
489 | MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO } /* Then, make it r/o */ | |
490 | ||
e83bebef LP |
491 | typedef struct MountPoint { |
492 | const char *what; | |
493 | const char *where; | |
494 | const char *type; | |
495 | const char *options; | |
496 | unsigned long flags; | |
4f086aab | 497 | MountSettingsMask mount_settings; |
e83bebef LP |
498 | } MountPoint; |
499 | ||
500 | static const MountPoint mount_table[] = { | |
d4b653c5 LP |
501 | /* First we list inner child mounts (i.e. mounts applied *after* entering user namespacing) */ |
502 | { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
511a8cfe | 503 | 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 |
504 | |
505 | { "/proc/sys", "/proc/sys", NULL, NULL, MS_BIND, | |
506 | MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* Bind mount first ... */ | |
507 | ||
508 | { "/proc/sys/net", "/proc/sys/net", NULL, NULL, MS_BIND, | |
509 | MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO|MOUNT_APPLY_APIVFS_NETNS }, /* (except for this) */ | |
510 | ||
511 | { NULL, "/proc/sys", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, | |
512 | MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* ... then, make it r/o */ | |
513 | ||
514 | /* Make these files inaccessible to container payloads: they potentially leak information about kernel | |
515 | * internals or the host's execution environment to the container */ | |
de40a303 LP |
516 | PROC_INACCESSIBLE_REG("/proc/kallsyms"), |
517 | PROC_INACCESSIBLE_REG("/proc/kcore"), | |
518 | PROC_INACCESSIBLE_REG("/proc/keys"), | |
519 | PROC_INACCESSIBLE_REG("/proc/sysrq-trigger"), | |
520 | PROC_INACCESSIBLE_REG("/proc/timer_list"), | |
d4b653c5 LP |
521 | |
522 | /* Make these directories read-only to container payloads: they show hardware information, and in some | |
523 | * cases contain tunables the container really shouldn't have access to. */ | |
524 | PROC_READ_ONLY("/proc/acpi"), | |
525 | PROC_READ_ONLY("/proc/apm"), | |
526 | PROC_READ_ONLY("/proc/asound"), | |
527 | PROC_READ_ONLY("/proc/bus"), | |
528 | PROC_READ_ONLY("/proc/fs"), | |
529 | PROC_READ_ONLY("/proc/irq"), | |
530 | PROC_READ_ONLY("/proc/scsi"), | |
531 | ||
e1bb4b0d | 532 | { "mqueue", "/dev/mqueue", "mqueue", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
dcff2fa5 | 533 | MOUNT_IN_USERNS|MOUNT_MKDIR }, |
849b9b85 | 534 | |
d4b653c5 | 535 | /* Then we list outer child mounts (i.e. mounts applied *before* entering user namespacing) */ |
b67ec8e5 | 536 | { "tmpfs", "/tmp", "tmpfs", "mode=1777" NESTED_TMPFS_LIMITS, MS_NOSUID|MS_NODEV|MS_STRICTATIME, |
dcff2fa5 | 537 | MOUNT_FATAL|MOUNT_APPLY_TMPFS_TMP|MOUNT_MKDIR }, |
e1bb4b0d | 538 | { "tmpfs", "/sys", "tmpfs", "mode=555" TMPFS_LIMITS_SYS, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
dcff2fa5 | 539 | MOUNT_FATAL|MOUNT_APPLY_APIVFS_NETNS|MOUNT_MKDIR }, |
e1bb4b0d | 540 | { "sysfs", "/sys", "sysfs", NULL, MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, |
dcff2fa5 | 541 | MOUNT_FATAL|MOUNT_APPLY_APIVFS_RO|MOUNT_MKDIR }, /* skipped if above was mounted */ |
e1bb4b0d | 542 | { "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
dcff2fa5 | 543 | MOUNT_FATAL|MOUNT_MKDIR }, /* skipped if above was mounted */ |
e1bb4b0d | 544 | { "tmpfs", "/dev", "tmpfs", "mode=755" TMPFS_LIMITS_DEV, MS_NOSUID|MS_STRICTATIME, |
dcff2fa5 | 545 | MOUNT_FATAL|MOUNT_MKDIR }, |
b67ec8e5 | 546 | { "tmpfs", "/dev/shm", "tmpfs", "mode=1777" NESTED_TMPFS_LIMITS, MS_NOSUID|MS_NODEV|MS_STRICTATIME, |
dcff2fa5 | 547 | MOUNT_FATAL|MOUNT_MKDIR }, |
e1bb4b0d | 548 | { "tmpfs", "/run", "tmpfs", "mode=755" TMPFS_LIMITS_RUN, MS_NOSUID|MS_NODEV|MS_STRICTATIME, |
dcff2fa5 | 549 | MOUNT_FATAL|MOUNT_MKDIR }, |
d64e32c2 LP |
550 | { "/run/host", "/run/host", NULL, NULL, MS_BIND, |
551 | MOUNT_FATAL|MOUNT_MKDIR|MOUNT_PREFIX_ROOT }, /* Prepare this so that we can make it read-only when we are done */ | |
552 | { "/etc/os-release", "/run/host/os-release", NULL, NULL, MS_BIND, | |
553 | MOUNT_TOUCH }, /* As per kernel interface requirements, bind mount first (creating mount points) and make read-only later */ | |
554 | { "/usr/lib/os-release", "/run/host/os-release", NULL, NULL, MS_BIND, | |
555 | MOUNT_FATAL }, /* If /etc/os-release doesn't exist use the version in /usr/lib as fallback */ | |
556 | { NULL, "/run/host/os-release", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, | |
557 | MOUNT_FATAL }, | |
558 | { NULL, "/run/host", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, | |
559 | MOUNT_FATAL|MOUNT_IN_USERNS }, | |
349cc4a5 | 560 | #if HAVE_SELINUX |
e1bb4b0d | 561 | { "/sys/fs/selinux", "/sys/fs/selinux", NULL, NULL, MS_BIND, |
6fe01ced | 562 | MOUNT_MKDIR }, /* Bind mount first (mkdir/chown the mount point in case /sys/ is mounted as minimal skeleton tmpfs) */ |
e1bb4b0d | 563 | { NULL, "/sys/fs/selinux", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, |
6fe01ced | 564 | 0 }, /* Then, make it r/o (don't mkdir/chown the mount point here, the previous entry already did that) */ |
e83bebef LP |
565 | #endif |
566 | }; | |
567 | ||
bd6609eb DDM |
568 | bool use_userns = FLAGS_SET(mount_settings, MOUNT_USE_USERNS); |
569 | bool netns = FLAGS_SET(mount_settings, MOUNT_APPLY_APIVFS_NETNS); | |
570 | bool ro = FLAGS_SET(mount_settings, MOUNT_APPLY_APIVFS_RO); | |
571 | bool in_userns = FLAGS_SET(mount_settings, MOUNT_IN_USERNS); | |
572 | bool tmpfs_tmp = FLAGS_SET(mount_settings, MOUNT_APPLY_TMPFS_TMP); | |
88614c8a | 573 | int r; |
e83bebef | 574 | |
d2b99ed7 | 575 | for (size_t k = 0; k < ELEMENTSOF(mount_table); k++) { |
d64e32c2 | 576 | _cleanup_free_ char *where = NULL, *options = NULL, *prefixed = NULL; |
bd6609eb | 577 | bool fatal = FLAGS_SET(mount_table[k].mount_settings, MOUNT_FATAL); |
d64e32c2 | 578 | const char *o; |
4f086aab | 579 | |
bd6609eb | 580 | if (in_userns != FLAGS_SET(mount_table[k].mount_settings, MOUNT_IN_USERNS)) |
4f086aab | 581 | continue; |
e83bebef | 582 | |
bd6609eb | 583 | if (!netns && FLAGS_SET(mount_table[k].mount_settings, MOUNT_APPLY_APIVFS_NETNS)) |
d1678248 ILG |
584 | continue; |
585 | ||
bd6609eb | 586 | if (!ro && FLAGS_SET(mount_table[k].mount_settings, MOUNT_APPLY_APIVFS_RO)) |
e83bebef LP |
587 | continue; |
588 | ||
bd6609eb | 589 | if (!tmpfs_tmp && FLAGS_SET(mount_table[k].mount_settings, MOUNT_APPLY_TMPFS_TMP)) |
1099ceeb LP |
590 | continue; |
591 | ||
a5648b80 | 592 | r = chase_symlinks(mount_table[k].where, dest, CHASE_NONEXISTENT|CHASE_PREFIX_ROOT, &where, NULL); |
8ce48cf0 | 593 | if (r < 0) |
ec57bd42 | 594 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, mount_table[k].where); |
e83bebef | 595 | |
e83bebef | 596 | /* Skip this entry if it is not a remount. */ |
de40a303 LP |
597 | if (mount_table[k].what) { |
598 | r = path_is_mount_point(where, NULL, 0); | |
599 | if (r < 0 && r != -ENOENT) | |
600 | return log_error_errno(r, "Failed to detect whether %s is a mount point: %m", where); | |
601 | if (r > 0) | |
602 | continue; | |
603 | } | |
e83bebef | 604 | |
d64e32c2 | 605 | if ((mount_table[k].mount_settings & (MOUNT_MKDIR|MOUNT_TOUCH)) != 0) { |
b3b1a08a | 606 | uid_t u = (use_userns && !in_userns) ? uid_shift : UID_INVALID; |
e1bb4b0d LB |
607 | |
608 | if (FLAGS_SET(mount_table[k].mount_settings, MOUNT_TOUCH)) | |
609 | r = mkdir_parents_safe(dest, where, 0755, u, u, 0); | |
610 | else | |
611 | r = mkdir_p_safe(dest, where, 0755, u, u, 0); | |
dcff2fa5 LP |
612 | if (r < 0 && r != -EEXIST) { |
613 | if (fatal && r != -EROFS) | |
614 | return log_error_errno(r, "Failed to create directory %s: %m", where); | |
e83bebef | 615 | |
dcff2fa5 LP |
616 | log_debug_errno(r, "Failed to create directory %s: %m", where); |
617 | ||
618 | /* If we failed mkdir() or chown() due to the root directory being read only, | |
619 | * attempt to mount this fs anyway and let mount_verbose log any errors */ | |
620 | if (r != -EROFS) | |
621 | continue; | |
622 | } | |
d64e32c2 LP |
623 | } |
624 | ||
625 | if (FLAGS_SET(mount_table[k].mount_settings, MOUNT_TOUCH)) { | |
626 | r = touch(where); | |
627 | if (r < 0 && r != -EEXIST) { | |
628 | if (fatal && r != -EROFS) | |
629 | return log_error_errno(r, "Failed to create file %s: %m", where); | |
630 | ||
631 | log_debug_errno(r, "Failed to create file %s: %m", where); | |
632 | if (r != -EROFS) | |
633 | continue; | |
e1bb4b0d | 634 | } |
e83bebef LP |
635 | } |
636 | ||
637 | o = mount_table[k].options; | |
638 | if (streq_ptr(mount_table[k].type, "tmpfs")) { | |
2fa017f1 | 639 | r = tmpfs_patch_options(o, in_userns ? 0 : uid_shift, selinux_apifs_context, &options); |
e83bebef LP |
640 | if (r < 0) |
641 | return log_oom(); | |
642 | if (r > 0) | |
643 | o = options; | |
644 | } | |
645 | ||
d64e32c2 LP |
646 | if (FLAGS_SET(mount_table[k].mount_settings, MOUNT_PREFIX_ROOT)) { |
647 | /* Optionally prefix the mount source with the root dir. This is useful in bind | |
648 | * mounts to be created within the container image before we transition into it. Note | |
649 | * that MOUNT_IN_USERNS is run after we transitioned hence prefixing is not ncessary | |
650 | * for those. */ | |
651 | r = chase_symlinks(mount_table[k].what, dest, CHASE_PREFIX_ROOT, &prefixed, NULL); | |
652 | if (r < 0) | |
653 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, mount_table[k].what); | |
654 | } | |
655 | ||
511a8cfe LP |
656 | r = mount_verbose_full( |
657 | fatal ? LOG_ERR : LOG_DEBUG, | |
658 | prefixed ?: mount_table[k].what, | |
659 | where, | |
660 | mount_table[k].type, | |
661 | mount_table[k].flags, | |
662 | o, | |
663 | FLAGS_SET(mount_table[k].mount_settings, MOUNT_FOLLOW_SYMLINKS)); | |
4f086aab | 664 | if (r < 0 && fatal) |
60e76d48 | 665 | return r; |
e83bebef LP |
666 | } |
667 | ||
668 | return 0; | |
669 | } | |
670 | ||
c0c8f718 | 671 | static int parse_mount_bind_options(const char *options, unsigned long *mount_flags, char **mount_opts, bool *idmapped) { |
a11fd406 ILG |
672 | unsigned long flags = *mount_flags; |
673 | char *opts = NULL; | |
c0c8f718 | 674 | bool flag_idmapped = *idmapped; |
a11fd406 ILG |
675 | int r; |
676 | ||
677 | assert(options); | |
678 | ||
679 | for (;;) { | |
680 | _cleanup_free_ char *word = NULL; | |
681 | ||
d2b99ed7 | 682 | r = extract_first_word(&options, &word, ",", 0); |
a11fd406 ILG |
683 | if (r < 0) |
684 | return log_error_errno(r, "Failed to extract mount option: %m"); | |
685 | if (r == 0) | |
686 | break; | |
687 | ||
688 | if (streq(word, "rbind")) | |
689 | flags |= MS_REC; | |
690 | else if (streq(word, "norbind")) | |
691 | flags &= ~MS_REC; | |
c0c8f718 AV |
692 | else if (streq(word, "idmap")) |
693 | flag_idmapped = true; | |
694 | else if (streq(word, "noidmap")) | |
695 | flag_idmapped = false; | |
d2b99ed7 | 696 | else |
38288f0b | 697 | return log_error_errno(SYNTHETIC_ERRNO(EINVAL), |
d2b99ed7 | 698 | "Invalid bind mount option: %s", word); |
a11fd406 ILG |
699 | } |
700 | ||
701 | *mount_flags = flags; | |
c0c8f718 | 702 | *idmapped = flag_idmapped; |
a11fd406 ILG |
703 | /* in the future mount_opts will hold string options for mount(2) */ |
704 | *mount_opts = opts; | |
705 | ||
706 | return 0; | |
707 | } | |
708 | ||
c0c8f718 | 709 | static int mount_bind(const char *dest, CustomMount *m, uid_t uid_shift, uid_t uid_range) { |
a11fd406 ILG |
710 | _cleanup_free_ char *mount_opts = NULL, *where = NULL; |
711 | unsigned long mount_flags = MS_BIND | MS_REC; | |
68cf43c3 | 712 | struct stat source_st, dest_st; |
e83bebef | 713 | int r; |
c0c8f718 | 714 | bool idmapped = false; |
e83bebef | 715 | |
86c0dd4a | 716 | assert(dest); |
e83bebef LP |
717 | assert(m); |
718 | ||
a11fd406 | 719 | if (m->options) { |
c0c8f718 | 720 | r = parse_mount_bind_options(m->options, &mount_flags, &mount_opts, &idmapped); |
a11fd406 ILG |
721 | if (r < 0) |
722 | return r; | |
723 | } | |
724 | ||
07bca16f LP |
725 | /* If this is a bind mount from a temporary sources change ownership of the source to the container's |
726 | * root UID. Otherwise it would always show up as "nobody" if user namespacing is used. */ | |
727 | if (m->rm_rf_tmpdir && chown(m->source, uid_shift, uid_shift) < 0) | |
728 | return log_error_errno(errno, "Failed to chown %s: %m", m->source); | |
729 | ||
e83bebef LP |
730 | if (stat(m->source, &source_st) < 0) |
731 | return log_error_errno(errno, "Failed to stat %s: %m", m->source); | |
732 | ||
a5648b80 | 733 | r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); |
68cf43c3 | 734 | if (r < 0) |
ec57bd42 | 735 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); |
8ce48cf0 LP |
736 | if (r > 0) { /* Path exists already? */ |
737 | ||
738 | if (stat(where, &dest_st) < 0) | |
739 | return log_error_errno(errno, "Failed to stat %s: %m", where); | |
e83bebef | 740 | |
baaa35ad ZJS |
741 | if (S_ISDIR(source_st.st_mode) && !S_ISDIR(dest_st.st_mode)) |
742 | return log_error_errno(SYNTHETIC_ERRNO(EINVAL), | |
743 | "Cannot bind mount directory %s on file %s.", | |
744 | m->source, where); | |
745 | ||
746 | if (!S_ISDIR(source_st.st_mode) && S_ISDIR(dest_st.st_mode)) | |
747 | return log_error_errno(SYNTHETIC_ERRNO(EINVAL), | |
748 | "Cannot bind mount file %s on directory %s.", | |
749 | m->source, where); | |
e83bebef | 750 | |
8ce48cf0 | 751 | } else { /* Path doesn't exist yet? */ |
e83bebef LP |
752 | r = mkdir_parents_label(where, 0755); |
753 | if (r < 0) | |
754 | return log_error_errno(r, "Failed to make parents of %s: %m", where); | |
b97e83cb BN |
755 | |
756 | /* Create the mount point. Any non-directory file can be | |
757 | * mounted on any non-directory file (regular, fifo, socket, | |
758 | * char, block). | |
759 | */ | |
760 | if (S_ISDIR(source_st.st_mode)) | |
761 | r = mkdir_label(where, 0755); | |
762 | else | |
763 | r = touch(where); | |
764 | if (r < 0) | |
765 | return log_error_errno(r, "Failed to create mount point %s: %m", where); | |
8ce48cf0 | 766 | } |
e83bebef | 767 | |
511a8cfe | 768 | r = mount_nofollow_verbose(LOG_ERR, m->source, where, NULL, mount_flags, mount_opts); |
60e76d48 ZJS |
769 | if (r < 0) |
770 | return r; | |
e83bebef LP |
771 | |
772 | if (m->read_only) { | |
64e82c19 | 773 | r = bind_remount_recursive(where, MS_RDONLY, MS_RDONLY, NULL); |
e83bebef LP |
774 | if (r < 0) |
775 | return log_error_errno(r, "Read-only bind mount failed: %m"); | |
776 | } | |
777 | ||
c0c8f718 | 778 | if (idmapped) { |
50ae2966 | 779 | r = remount_idmap(where, uid_shift, uid_range, REMOUNT_IDMAP_HOST_ROOT); |
c0c8f718 AV |
780 | if (r < 0) |
781 | return log_error_errno(r, "Failed to map ids for bind mount %s: %m", where); | |
782 | } | |
783 | ||
e83bebef LP |
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) { |
68cf43c3 LP |
788 | const char *options; |
789 | _cleanup_free_ char *buf = NULL, *where = NULL; | |
e83bebef LP |
790 | int r; |
791 | ||
792 | assert(dest); | |
793 | assert(m); | |
794 | ||
a5648b80 | 795 | r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); |
68cf43c3 | 796 | if (r < 0) |
ec57bd42 | 797 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); |
8ce48cf0 LP |
798 | if (r == 0) { /* Doesn't exist yet? */ |
799 | r = mkdir_p_label(where, 0755); | |
800 | if (r < 0) | |
801 | return log_error_errno(r, "Creating mount point for tmpfs %s failed: %m", where); | |
802 | } | |
e83bebef | 803 | |
2fa017f1 | 804 | r = tmpfs_patch_options(m->options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); |
e83bebef LP |
805 | if (r < 0) |
806 | return log_oom(); | |
807 | options = r > 0 ? buf : m->options; | |
808 | ||
511a8cfe | 809 | return mount_nofollow_verbose(LOG_ERR, "tmpfs", where, "tmpfs", MS_NODEV|MS_STRICTATIME, options); |
e83bebef LP |
810 | } |
811 | ||
86c0dd4a | 812 | static char *joined_and_escaped_lower_dirs(char **lower) { |
e83bebef LP |
813 | _cleanup_strv_free_ char **sv = NULL; |
814 | ||
815 | sv = strv_copy(lower); | |
816 | if (!sv) | |
817 | return NULL; | |
818 | ||
819 | strv_reverse(sv); | |
820 | ||
821 | if (!strv_shell_escape(sv, ",:")) | |
822 | return NULL; | |
823 | ||
824 | return strv_join(sv, ":"); | |
825 | } | |
826 | ||
827 | static int mount_overlay(const char *dest, CustomMount *m) { | |
86c0dd4a | 828 | _cleanup_free_ char *lower = NULL, *where = NULL, *escaped_source = NULL; |
68cf43c3 | 829 | const char *options; |
e83bebef LP |
830 | int r; |
831 | ||
832 | assert(dest); | |
833 | assert(m); | |
834 | ||
a5648b80 | 835 | r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); |
68cf43c3 | 836 | if (r < 0) |
ec57bd42 | 837 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); |
8ce48cf0 LP |
838 | if (r == 0) { /* Doesn't exist yet? */ |
839 | r = mkdir_label(where, 0755); | |
840 | if (r < 0) | |
841 | return log_error_errno(r, "Creating mount point for overlay %s failed: %m", where); | |
842 | } | |
e83bebef LP |
843 | |
844 | (void) mkdir_p_label(m->source, 0755); | |
845 | ||
846 | lower = joined_and_escaped_lower_dirs(m->lower); | |
847 | if (!lower) | |
848 | return log_oom(); | |
849 | ||
86c0dd4a LP |
850 | escaped_source = shell_escape(m->source, ",:"); |
851 | if (!escaped_source) | |
852 | return log_oom(); | |
e83bebef | 853 | |
86c0dd4a | 854 | if (m->read_only) |
e83bebef | 855 | options = strjoina("lowerdir=", escaped_source, ":", lower); |
86c0dd4a LP |
856 | else { |
857 | _cleanup_free_ char *escaped_work_dir = NULL; | |
e83bebef | 858 | |
e83bebef LP |
859 | escaped_work_dir = shell_escape(m->work_dir, ",:"); |
860 | if (!escaped_work_dir) | |
861 | return log_oom(); | |
862 | ||
863 | options = strjoina("lowerdir=", lower, ",upperdir=", escaped_source, ",workdir=", escaped_work_dir); | |
864 | } | |
865 | ||
511a8cfe | 866 | return mount_nofollow_verbose(LOG_ERR, "overlay", where, "overlay", m->read_only ? MS_RDONLY : 0, options); |
e83bebef LP |
867 | } |
868 | ||
de40a303 | 869 | static int mount_inaccessible(const char *dest, CustomMount *m) { |
e5f10caf | 870 | _cleanup_free_ char *where = NULL, *source = NULL; |
de40a303 LP |
871 | struct stat st; |
872 | int r; | |
873 | ||
874 | assert(dest); | |
875 | assert(m); | |
876 | ||
a5648b80 | 877 | r = chase_symlinks_and_stat(m->destination, dest, CHASE_PREFIX_ROOT, &where, &st, NULL); |
de40a303 LP |
878 | if (r < 0) { |
879 | log_full_errno(m->graceful ? LOG_DEBUG : LOG_ERR, r, "Failed to resolve %s/%s: %m", dest, m->destination); | |
880 | return m->graceful ? 0 : r; | |
881 | } | |
882 | ||
48b747fa | 883 | r = mode_to_inaccessible_node(NULL, st.st_mode, &source); |
e5f10caf AZ |
884 | if (r < 0) |
885 | return m->graceful ? 0 : r; | |
de40a303 | 886 | |
511a8cfe | 887 | r = mount_nofollow_verbose(m->graceful ? LOG_DEBUG : LOG_ERR, source, where, NULL, MS_BIND, NULL); |
de40a303 LP |
888 | if (r < 0) |
889 | return m->graceful ? 0 : r; | |
890 | ||
511a8cfe | 891 | r = mount_nofollow_verbose(m->graceful ? LOG_DEBUG : LOG_ERR, NULL, where, NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, NULL); |
2c9b7a7e | 892 | if (r < 0) { |
30f5d104 | 893 | (void) umount_verbose(m->graceful ? LOG_DEBUG : LOG_ERR, where, UMOUNT_NOFOLLOW); |
de40a303 | 894 | return m->graceful ? 0 : r; |
2c9b7a7e | 895 | } |
de40a303 LP |
896 | |
897 | return 0; | |
898 | } | |
899 | ||
900 | static int mount_arbitrary(const char *dest, CustomMount *m) { | |
901 | _cleanup_free_ char *where = NULL; | |
902 | int r; | |
903 | ||
904 | assert(dest); | |
905 | assert(m); | |
906 | ||
a5648b80 | 907 | r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); |
de40a303 LP |
908 | if (r < 0) |
909 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); | |
910 | if (r == 0) { /* Doesn't exist yet? */ | |
911 | r = mkdir_p_label(where, 0755); | |
912 | if (r < 0) | |
913 | return log_error_errno(r, "Creating mount point for mount %s failed: %m", where); | |
914 | } | |
915 | ||
511a8cfe | 916 | return mount_nofollow_verbose(LOG_ERR, m->source, where, m->type_argument, 0, m->options); |
de40a303 LP |
917 | } |
918 | ||
e83bebef LP |
919 | int mount_custom( |
920 | const char *dest, | |
88614c8a | 921 | CustomMount *mounts, size_t n, |
e091a5df | 922 | uid_t uid_shift, |
c0c8f718 | 923 | uid_t uid_range, |
de40a303 | 924 | const char *selinux_apifs_context, |
5f0a6347 | 925 | MountSettingsMask mount_settings) { |
e83bebef LP |
926 | int r; |
927 | ||
928 | assert(dest); | |
929 | ||
d2b99ed7 | 930 | for (size_t i = 0; i < n; i++) { |
e83bebef LP |
931 | CustomMount *m = mounts + i; |
932 | ||
bd6609eb | 933 | if (FLAGS_SET(mount_settings, MOUNT_IN_USERNS) != m->in_userns) |
5f0a6347 DDM |
934 | continue; |
935 | ||
bd6609eb | 936 | if (FLAGS_SET(mount_settings, MOUNT_ROOT_ONLY) && !path_equal(m->destination, "/")) |
5f0a6347 DDM |
937 | continue; |
938 | ||
bd6609eb | 939 | if (FLAGS_SET(mount_settings, MOUNT_NON_ROOT_ONLY) && path_equal(m->destination, "/")) |
de40a303 LP |
940 | continue; |
941 | ||
e83bebef LP |
942 | switch (m->type) { |
943 | ||
944 | case CUSTOM_MOUNT_BIND: | |
c0c8f718 | 945 | r = mount_bind(dest, m, uid_shift, uid_range); |
e83bebef LP |
946 | break; |
947 | ||
948 | case CUSTOM_MOUNT_TMPFS: | |
e091a5df | 949 | r = mount_tmpfs(dest, m, uid_shift, selinux_apifs_context); |
e83bebef LP |
950 | break; |
951 | ||
952 | case CUSTOM_MOUNT_OVERLAY: | |
953 | r = mount_overlay(dest, m); | |
954 | break; | |
955 | ||
de40a303 LP |
956 | case CUSTOM_MOUNT_INACCESSIBLE: |
957 | r = mount_inaccessible(dest, m); | |
958 | break; | |
959 | ||
960 | case CUSTOM_MOUNT_ARBITRARY: | |
961 | r = mount_arbitrary(dest, m); | |
962 | break; | |
963 | ||
e83bebef | 964 | default: |
04499a70 | 965 | assert_not_reached(); |
e83bebef LP |
966 | } |
967 | ||
968 | if (r < 0) | |
969 | return r; | |
970 | } | |
971 | ||
972 | return 0; | |
973 | } | |
974 | ||
bbd407ea | 975 | bool has_custom_root_mount(const CustomMount *mounts, size_t n) { |
d2b99ed7 ZJS |
976 | for (size_t i = 0; i < n; i++) |
977 | if (path_equal(mounts[i].destination, "/")) | |
bbd407ea | 978 | return true; |
bbd407ea DDM |
979 | |
980 | return false; | |
981 | } | |
982 | ||
e091a5df | 983 | static int setup_volatile_state(const char *directory, uid_t uid_shift, const char *selinux_apifs_context) { |
e83bebef LP |
984 | _cleanup_free_ char *buf = NULL; |
985 | const char *p, *options; | |
986 | int r; | |
987 | ||
988 | assert(directory); | |
989 | ||
e5b43a04 | 990 | /* --volatile=state means we simply overmount /var with a tmpfs, and the rest read-only. */ |
e83bebef | 991 | |
64e82c19 | 992 | r = bind_remount_recursive(directory, MS_RDONLY, MS_RDONLY, NULL); |
e83bebef LP |
993 | if (r < 0) |
994 | return log_error_errno(r, "Failed to remount %s read-only: %m", directory); | |
995 | ||
996 | p = prefix_roota(directory, "/var"); | |
997 | r = mkdir(p, 0755); | |
998 | if (r < 0 && errno != EEXIST) | |
999 | return log_error_errno(errno, "Failed to create %s: %m", directory); | |
1000 | ||
7d85383e | 1001 | options = "mode=755" TMPFS_LIMITS_VOLATILE_STATE; |
2fa017f1 | 1002 | r = tmpfs_patch_options(options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); |
e83bebef LP |
1003 | if (r < 0) |
1004 | return log_oom(); | |
1005 | if (r > 0) | |
1006 | options = buf; | |
1007 | ||
511a8cfe | 1008 | return mount_nofollow_verbose(LOG_ERR, "tmpfs", p, "tmpfs", MS_STRICTATIME, options); |
e83bebef LP |
1009 | } |
1010 | ||
e091a5df | 1011 | static int setup_volatile_yes(const char *directory, uid_t uid_shift, const char *selinux_apifs_context) { |
e83bebef LP |
1012 | bool tmpfs_mounted = false, bind_mounted = false; |
1013 | char template[] = "/tmp/nspawn-volatile-XXXXXX"; | |
07b9f3f0 | 1014 | _cleanup_free_ char *buf = NULL, *bindir = NULL; |
e83bebef | 1015 | const char *f, *t, *options; |
07b9f3f0 | 1016 | struct stat st; |
e83bebef LP |
1017 | int r; |
1018 | ||
1019 | assert(directory); | |
1020 | ||
07b9f3f0 LP |
1021 | /* --volatile=yes means we mount a tmpfs to the root dir, and the original /usr to use inside it, and |
1022 | * that read-only. Before we start setting this up let's validate if the image has the /usr merge | |
1023 | * implemented, and let's output a friendly log message if it hasn't. */ | |
1024 | ||
1025 | bindir = path_join(directory, "/bin"); | |
1026 | if (!bindir) | |
1027 | return log_oom(); | |
1028 | if (lstat(bindir, &st) < 0) { | |
1029 | if (errno != ENOENT) | |
1030 | return log_error_errno(errno, "Failed to stat /bin directory below image: %m"); | |
1031 | ||
1032 | /* ENOENT is fine, just means the image is probably just a naked /usr and we can create the | |
1033 | * rest. */ | |
1034 | } else if (S_ISDIR(st.st_mode)) | |
1035 | return log_error_errno(SYNTHETIC_ERRNO(EISDIR), | |
1036 | "Sorry, --volatile=yes mode is not supported with OS images that have not merged /bin/, /sbin/, /lib/, /lib64/ into /usr/. " | |
1037 | "Please work with your distribution and help them adopt the merged /usr scheme."); | |
1038 | else if (!S_ISLNK(st.st_mode)) | |
1039 | return log_error_errno(SYNTHETIC_ERRNO(EINVAL), | |
1040 | "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 |
1041 | |
1042 | if (!mkdtemp(template)) | |
1043 | return log_error_errno(errno, "Failed to create temporary directory: %m"); | |
1044 | ||
7d85383e | 1045 | options = "mode=755" TMPFS_LIMITS_ROOTFS; |
2fa017f1 | 1046 | r = tmpfs_patch_options(options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); |
e83bebef | 1047 | if (r < 0) |
c55d0ae7 | 1048 | goto fail; |
e83bebef LP |
1049 | if (r > 0) |
1050 | options = buf; | |
1051 | ||
511a8cfe | 1052 | r = mount_nofollow_verbose(LOG_ERR, "tmpfs", template, "tmpfs", MS_STRICTATIME, options); |
60e76d48 | 1053 | if (r < 0) |
e83bebef | 1054 | goto fail; |
e83bebef LP |
1055 | |
1056 | tmpfs_mounted = true; | |
1057 | ||
1058 | f = prefix_roota(directory, "/usr"); | |
1059 | t = prefix_roota(template, "/usr"); | |
1060 | ||
1061 | r = mkdir(t, 0755); | |
1062 | if (r < 0 && errno != EEXIST) { | |
1063 | r = log_error_errno(errno, "Failed to create %s: %m", t); | |
1064 | goto fail; | |
1065 | } | |
1066 | ||
511a8cfe | 1067 | r = mount_nofollow_verbose(LOG_ERR, f, t, NULL, MS_BIND|MS_REC, NULL); |
60e76d48 | 1068 | if (r < 0) |
e83bebef | 1069 | goto fail; |
e83bebef LP |
1070 | |
1071 | bind_mounted = true; | |
1072 | ||
64e82c19 | 1073 | r = bind_remount_recursive(t, MS_RDONLY, MS_RDONLY, NULL); |
e83bebef LP |
1074 | if (r < 0) { |
1075 | log_error_errno(r, "Failed to remount %s read-only: %m", t); | |
1076 | goto fail; | |
1077 | } | |
1078 | ||
511a8cfe | 1079 | r = mount_nofollow_verbose(LOG_ERR, template, directory, NULL, MS_MOVE, NULL); |
60e76d48 | 1080 | if (r < 0) |
e83bebef | 1081 | goto fail; |
e83bebef LP |
1082 | |
1083 | (void) rmdir(template); | |
1084 | ||
1085 | return 0; | |
1086 | ||
1087 | fail: | |
1088 | if (bind_mounted) | |
30f5d104 | 1089 | (void) umount_verbose(LOG_ERR, t, UMOUNT_NOFOLLOW); |
e83bebef LP |
1090 | |
1091 | if (tmpfs_mounted) | |
30f5d104 LP |
1092 | (void) umount_verbose(LOG_ERR, template, UMOUNT_NOFOLLOW); |
1093 | ||
e83bebef LP |
1094 | (void) rmdir(template); |
1095 | return r; | |
1096 | } | |
b53ede69 | 1097 | |
e091a5df | 1098 | static int setup_volatile_overlay(const char *directory, uid_t uid_shift, const char *selinux_apifs_context) { |
6c610aca LP |
1099 | _cleanup_free_ char *buf = NULL, *escaped_directory = NULL, *escaped_upper = NULL, *escaped_work = NULL; |
1100 | char template[] = "/tmp/nspawn-volatile-XXXXXX"; | |
1101 | const char *upper, *work, *options; | |
1102 | bool tmpfs_mounted = false; | |
1103 | int r; | |
1104 | ||
1105 | assert(directory); | |
1106 | ||
1107 | /* --volatile=overlay means we mount an overlayfs to the root dir. */ | |
1108 | ||
1109 | if (!mkdtemp(template)) | |
1110 | return log_error_errno(errno, "Failed to create temporary directory: %m"); | |
1111 | ||
7d85383e | 1112 | options = "mode=755" TMPFS_LIMITS_ROOTFS; |
6c610aca LP |
1113 | r = tmpfs_patch_options(options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); |
1114 | if (r < 0) | |
1115 | goto finish; | |
1116 | if (r > 0) | |
1117 | options = buf; | |
1118 | ||
511a8cfe | 1119 | r = mount_nofollow_verbose(LOG_ERR, "tmpfs", template, "tmpfs", MS_STRICTATIME, options); |
6c610aca LP |
1120 | if (r < 0) |
1121 | goto finish; | |
1122 | ||
1123 | tmpfs_mounted = true; | |
1124 | ||
1125 | upper = strjoina(template, "/upper"); | |
1126 | work = strjoina(template, "/work"); | |
1127 | ||
1128 | if (mkdir(upper, 0755) < 0) { | |
1129 | r = log_error_errno(errno, "Failed to create %s: %m", upper); | |
1130 | goto finish; | |
1131 | } | |
1132 | if (mkdir(work, 0755) < 0) { | |
1133 | r = log_error_errno(errno, "Failed to create %s: %m", work); | |
1134 | goto finish; | |
1135 | } | |
1136 | ||
1137 | /* And now, let's overmount the root dir with an overlayfs that uses the root dir as lower dir. It's kinda nice | |
1138 | * that the kernel allows us to do that without going through some mount point rearrangements. */ | |
1139 | ||
1140 | escaped_directory = shell_escape(directory, ",:"); | |
1141 | escaped_upper = shell_escape(upper, ",:"); | |
1142 | escaped_work = shell_escape(work, ",:"); | |
1143 | if (!escaped_directory || !escaped_upper || !escaped_work) { | |
1144 | r = -ENOMEM; | |
1145 | goto finish; | |
1146 | } | |
1147 | ||
1148 | options = strjoina("lowerdir=", escaped_directory, ",upperdir=", escaped_upper, ",workdir=", escaped_work); | |
511a8cfe | 1149 | r = mount_nofollow_verbose(LOG_ERR, "overlay", directory, "overlay", 0, options); |
6c610aca LP |
1150 | |
1151 | finish: | |
1152 | if (tmpfs_mounted) | |
30f5d104 | 1153 | (void) umount_verbose(LOG_ERR, template, UMOUNT_NOFOLLOW); |
6c610aca LP |
1154 | |
1155 | (void) rmdir(template); | |
1156 | return r; | |
1157 | } | |
1158 | ||
e5b43a04 LP |
1159 | int setup_volatile_mode( |
1160 | const char *directory, | |
1161 | VolatileMode mode, | |
e091a5df | 1162 | uid_t uid_shift, |
e5b43a04 LP |
1163 | const char *selinux_apifs_context) { |
1164 | ||
1165 | switch (mode) { | |
1166 | ||
1167 | case VOLATILE_YES: | |
e091a5df | 1168 | return setup_volatile_yes(directory, uid_shift, selinux_apifs_context); |
e5b43a04 LP |
1169 | |
1170 | case VOLATILE_STATE: | |
e091a5df | 1171 | return setup_volatile_state(directory, uid_shift, selinux_apifs_context); |
e5b43a04 | 1172 | |
6c610aca | 1173 | case VOLATILE_OVERLAY: |
e091a5df | 1174 | return setup_volatile_overlay(directory, uid_shift, selinux_apifs_context); |
6c610aca | 1175 | |
e5b43a04 LP |
1176 | default: |
1177 | return 0; | |
1178 | } | |
1179 | } | |
1180 | ||
b53ede69 PW |
1181 | /* Expects *pivot_root_new and *pivot_root_old to be initialised to allocated memory or NULL. */ |
1182 | int pivot_root_parse(char **pivot_root_new, char **pivot_root_old, const char *s) { | |
1183 | _cleanup_free_ char *root_new = NULL, *root_old = NULL; | |
1184 | const char *p = s; | |
1185 | int r; | |
1186 | ||
1187 | assert(pivot_root_new); | |
1188 | assert(pivot_root_old); | |
1189 | ||
1190 | r = extract_first_word(&p, &root_new, ":", EXTRACT_DONT_COALESCE_SEPARATORS); | |
1191 | if (r < 0) | |
1192 | return r; | |
1193 | if (r == 0) | |
1194 | return -EINVAL; | |
1195 | ||
1196 | if (isempty(p)) | |
1197 | root_old = NULL; | |
1198 | else { | |
1199 | root_old = strdup(p); | |
1200 | if (!root_old) | |
1201 | return -ENOMEM; | |
1202 | } | |
1203 | ||
1204 | if (!path_is_absolute(root_new)) | |
1205 | return -EINVAL; | |
1206 | if (root_old && !path_is_absolute(root_old)) | |
1207 | return -EINVAL; | |
1208 | ||
1209 | free_and_replace(*pivot_root_new, root_new); | |
1210 | free_and_replace(*pivot_root_old, root_old); | |
1211 | ||
1212 | return 0; | |
1213 | } | |
1214 | ||
1215 | int setup_pivot_root(const char *directory, const char *pivot_root_new, const char *pivot_root_old) { | |
1216 | _cleanup_free_ char *directory_pivot_root_new = NULL; | |
1217 | _cleanup_free_ char *pivot_tmp_pivot_root_old = NULL; | |
1218 | char pivot_tmp[] = "/tmp/nspawn-pivot-XXXXXX"; | |
1219 | bool remove_pivot_tmp = false; | |
1220 | int r; | |
1221 | ||
1222 | assert(directory); | |
1223 | ||
1224 | if (!pivot_root_new) | |
1225 | return 0; | |
1226 | ||
1227 | /* Pivot pivot_root_new to / and the existing / to pivot_root_old. | |
1228 | * If pivot_root_old is NULL, the existing / disappears. | |
1229 | * This requires a temporary directory, pivot_tmp, which is | |
1230 | * not a child of either. | |
1231 | * | |
1232 | * This is typically used for OSTree-style containers, where | |
1233 | * the root partition contains several sysroots which could be | |
1234 | * run. Normally, one would be chosen by the bootloader and | |
1235 | * pivoted to / by initramfs. | |
1236 | * | |
1237 | * For example, for an OSTree deployment, pivot_root_new | |
1238 | * would be: /ostree/deploy/$os/deploy/$checksum. Note that this | |
1239 | * code doesn’t do the /var mount which OSTree expects: use | |
1240 | * --bind +/sysroot/ostree/deploy/$os/var:/var for that. | |
1241 | * | |
1242 | * So in the OSTree case, we’ll end up with something like: | |
1243 | * - directory = /tmp/nspawn-root-123456 | |
1244 | * - pivot_root_new = /ostree/deploy/os/deploy/123abc | |
1245 | * - pivot_root_old = /sysroot | |
1246 | * - directory_pivot_root_new = | |
1247 | * /tmp/nspawn-root-123456/ostree/deploy/os/deploy/123abc | |
1248 | * - pivot_tmp = /tmp/nspawn-pivot-123456 | |
1249 | * - pivot_tmp_pivot_root_old = /tmp/nspawn-pivot-123456/sysroot | |
1250 | * | |
1251 | * Requires all file systems at directory and below to be mounted | |
1252 | * MS_PRIVATE or MS_SLAVE so they can be moved. | |
1253 | */ | |
c6134d3e LP |
1254 | directory_pivot_root_new = path_join(directory, pivot_root_new); |
1255 | if (!directory_pivot_root_new) | |
1256 | return log_oom(); | |
b53ede69 PW |
1257 | |
1258 | /* Remount directory_pivot_root_new to make it movable. */ | |
511a8cfe | 1259 | r = mount_nofollow_verbose(LOG_ERR, directory_pivot_root_new, directory_pivot_root_new, NULL, MS_BIND, NULL); |
b53ede69 PW |
1260 | if (r < 0) |
1261 | goto done; | |
1262 | ||
1263 | if (pivot_root_old) { | |
1264 | if (!mkdtemp(pivot_tmp)) { | |
1265 | r = log_error_errno(errno, "Failed to create temporary directory: %m"); | |
1266 | goto done; | |
1267 | } | |
1268 | ||
1269 | remove_pivot_tmp = true; | |
c6134d3e LP |
1270 | pivot_tmp_pivot_root_old = path_join(pivot_tmp, pivot_root_old); |
1271 | if (!pivot_tmp_pivot_root_old) { | |
1272 | r = log_oom(); | |
1273 | goto done; | |
1274 | } | |
b53ede69 | 1275 | |
511a8cfe | 1276 | r = mount_nofollow_verbose(LOG_ERR, directory_pivot_root_new, pivot_tmp, NULL, MS_MOVE, NULL); |
b53ede69 PW |
1277 | if (r < 0) |
1278 | goto done; | |
1279 | ||
511a8cfe | 1280 | r = mount_nofollow_verbose(LOG_ERR, directory, pivot_tmp_pivot_root_old, NULL, MS_MOVE, NULL); |
b53ede69 PW |
1281 | if (r < 0) |
1282 | goto done; | |
1283 | ||
511a8cfe | 1284 | r = mount_nofollow_verbose(LOG_ERR, pivot_tmp, directory, NULL, MS_MOVE, NULL); |
b53ede69 PW |
1285 | if (r < 0) |
1286 | goto done; | |
1287 | } else { | |
511a8cfe | 1288 | r = mount_nofollow_verbose(LOG_ERR, directory_pivot_root_new, directory, NULL, MS_MOVE, NULL); |
b53ede69 PW |
1289 | if (r < 0) |
1290 | goto done; | |
1291 | } | |
1292 | ||
1293 | done: | |
1294 | if (remove_pivot_tmp) | |
1295 | (void) rmdir(pivot_tmp); | |
1296 | ||
1297 | return r; | |
1298 | } |