]>
Commit | Line | Data |
---|---|---|
53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
15ae422b LP |
2 | /*** |
3 | This file is part of systemd. | |
4 | ||
5 | Copyright 2010 Lennart Poettering | |
15ae422b LP |
6 | ***/ |
7 | ||
8 | #include <errno.h> | |
07630cea | 9 | #include <sched.h> |
15ae422b | 10 | #include <stdio.h> |
07630cea LP |
11 | #include <string.h> |
12 | #include <sys/mount.h> | |
15ae422b | 13 | #include <sys/stat.h> |
07630cea | 14 | #include <unistd.h> |
25e870b5 | 15 | #include <linux/fs.h> |
15ae422b | 16 | |
b5efdb8a | 17 | #include "alloc-util.h" |
10404d52 | 18 | #include "base-filesystem.h" |
7f112f50 | 19 | #include "dev-setup.h" |
3ffd4af2 | 20 | #include "fd-util.h" |
d944dc95 | 21 | #include "fs-util.h" |
e908468b | 22 | #include "label.h" |
915e6d16 | 23 | #include "loop-util.h" |
07630cea LP |
24 | #include "loopback-setup.h" |
25 | #include "missing.h" | |
26 | #include "mkdir.h" | |
4349cd7c | 27 | #include "mount-util.h" |
3ffd4af2 | 28 | #include "namespace.h" |
07630cea | 29 | #include "path-util.h" |
d7b8eec7 | 30 | #include "selinux-util.h" |
2583fbea | 31 | #include "socket-util.h" |
36ce7110 | 32 | #include "stat-util.h" |
8b43440b | 33 | #include "string-table.h" |
07630cea LP |
34 | #include "string-util.h" |
35 | #include "strv.h" | |
affb60b1 | 36 | #include "umask-util.h" |
ee104e11 | 37 | #include "user-util.h" |
07630cea | 38 | #include "util.h" |
15ae422b | 39 | |
737ba3c8 | 40 | #define DEV_MOUNT_OPTIONS (MS_NOSUID|MS_STRICTATIME|MS_NOEXEC) |
41 | ||
c17ec25e | 42 | typedef enum MountMode { |
15ae422b LP |
43 | /* This is ordered by priority! */ |
44 | INACCESSIBLE, | |
d2d6c096 LP |
45 | BIND_MOUNT, |
46 | BIND_MOUNT_RECURSIVE, | |
ac0930c8 | 47 | PRIVATE_TMP, |
7f112f50 | 48 | PRIVATE_DEV, |
5d997827 | 49 | BIND_DEV, |
6c47cd7d | 50 | EMPTY_DIR, |
5d997827 LP |
51 | SYSFS, |
52 | PROCFS, | |
53 | READONLY, | |
59eeb84b | 54 | READWRITE, |
2abd4e38 | 55 | TMPFS, |
c17ec25e | 56 | } MountMode; |
15ae422b | 57 | |
34de407a | 58 | typedef struct MountEntry { |
5327c910 | 59 | const char *path_const; /* Memory allocated on stack or static */ |
cfbeb4ef | 60 | MountMode mode:5; |
5327c910 LP |
61 | bool ignore:1; /* Ignore if path does not exist? */ |
62 | bool has_prefix:1; /* Already is prefixed by the root dir? */ | |
cfbeb4ef | 63 | bool read_only:1; /* Shall this mount point be read-only? */ |
088696fe | 64 | bool applied:1; /* Already applied */ |
55fe7432 | 65 | char *path_malloc; /* Use this instead of 'path_const' if we had to allocate memory */ |
d2d6c096 LP |
66 | const char *source_const; /* The source path, for bind mounts */ |
67 | char *source_malloc; | |
2abd4e38 YW |
68 | const char *options_const;/* Mount options for tmpfs */ |
69 | char *options_malloc; | |
70 | unsigned long flags; /* Mount flags used by EMPTY_DIR and TMPFS. Do not include MS_RDONLY here, but please use read_only. */ | |
088696fe | 71 | unsigned n_followed; |
34de407a | 72 | } MountEntry; |
15ae422b | 73 | |
5d997827 LP |
74 | /* If MountAPIVFS= is used, let's mount /sys and /proc into the it, but only as a fallback if the user hasn't mounted |
75 | * something there already. These mounts are hence overriden by any other explicitly configured mounts. */ | |
76 | static const MountEntry apivfs_table[] = { | |
77 | { "/proc", PROCFS, false }, | |
78 | { "/dev", BIND_DEV, false }, | |
79 | { "/sys", SYSFS, false }, | |
80 | }; | |
f471b2af | 81 | |
11a30cec | 82 | /* ProtectKernelTunables= option and the related filesystem APIs */ |
34de407a | 83 | static const MountEntry protect_kernel_tunables_table[] = { |
c6232fb0 LP |
84 | { "/proc/sys", READONLY, false }, |
85 | { "/proc/sysrq-trigger", READONLY, true }, | |
86 | { "/proc/latency_stats", READONLY, true }, | |
87 | { "/proc/mtrr", READONLY, true }, | |
aa70f38b | 88 | { "/proc/apm", READONLY, true }, /* Obsolete API, there's no point in permitting access to this, ever */ |
c6232fb0 LP |
89 | { "/proc/acpi", READONLY, true }, |
90 | { "/proc/timer_stats", READONLY, true }, | |
91 | { "/proc/asound", READONLY, true }, | |
92 | { "/proc/bus", READONLY, true }, | |
93 | { "/proc/fs", READONLY, true }, | |
94 | { "/proc/irq", READONLY, true }, | |
95 | { "/sys", READONLY, false }, | |
96 | { "/sys/kernel/debug", READONLY, true }, | |
97 | { "/sys/kernel/tracing", READONLY, true }, | |
13a141f0 | 98 | { "/sys/fs/bpf", READONLY, true }, |
c6232fb0 | 99 | { "/sys/fs/cgroup", READWRITE, false }, /* READONLY is set by ProtectControlGroups= option */ |
3a0bf6d6 | 100 | { "/sys/fs/selinux", READWRITE, true }, |
11a30cec DH |
101 | }; |
102 | ||
c575770b | 103 | /* ProtectKernelModules= option */ |
34de407a | 104 | static const MountEntry protect_kernel_modules_table[] = { |
349cc4a5 | 105 | #if HAVE_SPLIT_USR |
c6232fb0 | 106 | { "/lib/modules", INACCESSIBLE, true }, |
c575770b | 107 | #endif |
c6232fb0 | 108 | { "/usr/lib/modules", INACCESSIBLE, true }, |
c575770b DH |
109 | }; |
110 | ||
b6c432ca DH |
111 | /* |
112 | * ProtectHome=read-only table, protect $HOME and $XDG_RUNTIME_DIR and rest of | |
113 | * system should be protected by ProtectSystem= | |
114 | */ | |
34de407a | 115 | static const MountEntry protect_home_read_only_table[] = { |
c6232fb0 LP |
116 | { "/home", READONLY, true }, |
117 | { "/run/user", READONLY, true }, | |
118 | { "/root", READONLY, true }, | |
b6c432ca DH |
119 | }; |
120 | ||
e4da7d8c YW |
121 | /* ProtectHome=tmpfs table */ |
122 | static const MountEntry protect_home_tmpfs_table[] = { | |
123 | { "/home", TMPFS, true, .read_only = true, .options_const = "mode=0755", .flags = MS_NODEV|MS_STRICTATIME }, | |
124 | { "/run/user", TMPFS, true, .read_only = true, .options_const = "mode=0755", .flags = MS_NODEV|MS_STRICTATIME }, | |
125 | { "/root", TMPFS, true, .read_only = true, .options_const = "mode=0700", .flags = MS_NODEV|MS_STRICTATIME }, | |
126 | }; | |
127 | ||
b6c432ca | 128 | /* ProtectHome=yes table */ |
34de407a | 129 | static const MountEntry protect_home_yes_table[] = { |
c6232fb0 LP |
130 | { "/home", INACCESSIBLE, true }, |
131 | { "/run/user", INACCESSIBLE, true }, | |
132 | { "/root", INACCESSIBLE, true }, | |
b6c432ca DH |
133 | }; |
134 | ||
f471b2af | 135 | /* ProtectSystem=yes table */ |
34de407a | 136 | static const MountEntry protect_system_yes_table[] = { |
c6232fb0 LP |
137 | { "/usr", READONLY, false }, |
138 | { "/boot", READONLY, true }, | |
139 | { "/efi", READONLY, true }, | |
7486f305 AB |
140 | #if HAVE_SPLIT_USR |
141 | { "/lib", READONLY, true }, | |
142 | { "/lib64", READONLY, true }, | |
143 | { "/bin", READONLY, true }, | |
671f0f8d | 144 | # if HAVE_SPLIT_BIN |
7486f305 | 145 | { "/sbin", READONLY, true }, |
671f0f8d | 146 | # endif |
7486f305 | 147 | #endif |
f471b2af DH |
148 | }; |
149 | ||
150 | /* ProtectSystem=full includes ProtectSystem=yes */ | |
34de407a | 151 | static const MountEntry protect_system_full_table[] = { |
c6232fb0 LP |
152 | { "/usr", READONLY, false }, |
153 | { "/boot", READONLY, true }, | |
154 | { "/efi", READONLY, true }, | |
155 | { "/etc", READONLY, false }, | |
7486f305 AB |
156 | #if HAVE_SPLIT_USR |
157 | { "/lib", READONLY, true }, | |
158 | { "/lib64", READONLY, true }, | |
159 | { "/bin", READONLY, true }, | |
671f0f8d | 160 | # if HAVE_SPLIT_BIN |
7486f305 | 161 | { "/sbin", READONLY, true }, |
671f0f8d | 162 | # endif |
7486f305 | 163 | #endif |
f471b2af DH |
164 | }; |
165 | ||
166 | /* | |
167 | * ProtectSystem=strict table. In this strict mode, we mount everything | |
168 | * read-only, except for /proc, /dev, /sys which are the kernel API VFS, | |
169 | * which are left writable, but PrivateDevices= + ProtectKernelTunables= | |
170 | * protect those, and these options should be fully orthogonal. | |
171 | * (And of course /home and friends are also left writable, as ProtectHome= | |
172 | * shall manage those, orthogonally). | |
173 | */ | |
34de407a | 174 | static const MountEntry protect_system_strict_table[] = { |
ddbe0412 LP |
175 | { "/", READONLY, false }, |
176 | { "/proc", READWRITE, false }, /* ProtectKernelTunables= */ | |
177 | { "/sys", READWRITE, false }, /* ProtectKernelTunables= */ | |
178 | { "/dev", READWRITE, false }, /* PrivateDevices= */ | |
179 | { "/home", READWRITE, true }, /* ProtectHome= */ | |
180 | { "/run/user", READWRITE, true }, /* ProtectHome= */ | |
181 | { "/root", READWRITE, true }, /* ProtectHome= */ | |
f471b2af DH |
182 | }; |
183 | ||
34de407a | 184 | static const char *mount_entry_path(const MountEntry *p) { |
f0a4feb0 DH |
185 | assert(p); |
186 | ||
5327c910 LP |
187 | /* Returns the path of this bind mount. If the malloc()-allocated ->path_buffer field is set we return that, |
188 | * otherwise the stack/static ->path field is returned. */ | |
f0a4feb0 | 189 | |
5327c910 | 190 | return p->path_malloc ?: p->path_const; |
f0a4feb0 DH |
191 | } |
192 | ||
34de407a | 193 | static bool mount_entry_read_only(const MountEntry *p) { |
cfbeb4ef LP |
194 | assert(p); |
195 | ||
196 | return p->read_only || IN_SET(p->mode, READONLY, INACCESSIBLE); | |
197 | } | |
198 | ||
d2d6c096 LP |
199 | static const char *mount_entry_source(const MountEntry *p) { |
200 | assert(p); | |
201 | ||
202 | return p->source_malloc ?: p->source_const; | |
203 | } | |
204 | ||
2abd4e38 YW |
205 | static const char *mount_entry_options(const MountEntry *p) { |
206 | assert(p); | |
207 | ||
208 | return p->options_malloc ?: p->options_const; | |
209 | } | |
210 | ||
1eb7e08e LP |
211 | static void mount_entry_done(MountEntry *p) { |
212 | assert(p); | |
213 | ||
214 | p->path_malloc = mfree(p->path_malloc); | |
215 | p->source_malloc = mfree(p->source_malloc); | |
2abd4e38 | 216 | p->options_malloc = mfree(p->options_malloc); |
1eb7e08e LP |
217 | } |
218 | ||
d18aff04 | 219 | static int append_access_mounts(MountEntry **p, char **strv, MountMode mode, bool forcibly_require_prefix) { |
15ae422b LP |
220 | char **i; |
221 | ||
613b411c LP |
222 | assert(p); |
223 | ||
5327c910 LP |
224 | /* Adds a list of user-supplied READWRITE/READONLY/INACCESSIBLE entries */ |
225 | ||
15ae422b | 226 | STRV_FOREACH(i, strv) { |
5327c910 LP |
227 | bool ignore = false, needs_prefix = false; |
228 | const char *e = *i; | |
15ae422b | 229 | |
5327c910 LP |
230 | /* Look for any prefixes */ |
231 | if (startswith(e, "-")) { | |
232 | e++; | |
9c94d52e | 233 | ignore = true; |
ea92ae33 | 234 | } |
5327c910 LP |
235 | if (startswith(e, "+")) { |
236 | e++; | |
237 | needs_prefix = true; | |
238 | } | |
ea92ae33 | 239 | |
5327c910 | 240 | if (!path_is_absolute(e)) |
15ae422b LP |
241 | return -EINVAL; |
242 | ||
34de407a | 243 | *((*p)++) = (MountEntry) { |
5327c910 LP |
244 | .path_const = e, |
245 | .mode = mode, | |
246 | .ignore = ignore, | |
d18aff04 | 247 | .has_prefix = !needs_prefix && !forcibly_require_prefix, |
5327c910 | 248 | }; |
15ae422b LP |
249 | } |
250 | ||
251 | return 0; | |
252 | } | |
253 | ||
6c47cd7d LP |
254 | static int append_empty_dir_mounts(MountEntry **p, char **strv) { |
255 | char **i; | |
256 | ||
257 | assert(p); | |
258 | ||
259 | /* Adds tmpfs mounts to provide readable but empty directories. This is primarily used to implement the | |
260 | * "/private/" boundary directories for DynamicUser=1. */ | |
261 | ||
262 | STRV_FOREACH(i, strv) { | |
263 | ||
264 | *((*p)++) = (MountEntry) { | |
265 | .path_const = *i, | |
266 | .mode = EMPTY_DIR, | |
267 | .ignore = false, | |
268 | .has_prefix = false, | |
269 | .read_only = true, | |
2abd4e38 YW |
270 | .options_const = "mode=755", |
271 | .flags = MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, | |
6c47cd7d LP |
272 | }; |
273 | } | |
274 | ||
275 | return 0; | |
276 | } | |
277 | ||
d2d6c096 LP |
278 | static int append_bind_mounts(MountEntry **p, const BindMount *binds, unsigned n) { |
279 | unsigned i; | |
280 | ||
281 | assert(p); | |
282 | ||
283 | for (i = 0; i < n; i++) { | |
284 | const BindMount *b = binds + i; | |
285 | ||
286 | *((*p)++) = (MountEntry) { | |
287 | .path_const = b->destination, | |
288 | .mode = b->recursive ? BIND_MOUNT_RECURSIVE : BIND_MOUNT, | |
289 | .read_only = b->read_only, | |
290 | .source_const = b->source, | |
4ca763a9 | 291 | .ignore = b->ignore_enoent, |
d2d6c096 LP |
292 | }; |
293 | } | |
294 | ||
295 | return 0; | |
296 | } | |
297 | ||
2abd4e38 YW |
298 | static int append_tmpfs_mounts(MountEntry **p, const TemporaryFileSystem *tmpfs, unsigned n) { |
299 | unsigned i; | |
300 | int r; | |
301 | ||
302 | assert(p); | |
303 | ||
304 | for (i = 0; i < n; i++) { | |
305 | const TemporaryFileSystem *t = tmpfs + i; | |
306 | _cleanup_free_ char *o = NULL, *str = NULL; | |
307 | unsigned long flags = MS_NODEV|MS_STRICTATIME; | |
308 | bool ro = false; | |
309 | ||
310 | if (!path_is_absolute(t->path)) | |
311 | return -EINVAL; | |
312 | ||
313 | if (!isempty(t->options)) { | |
314 | str = strjoin("mode=0755,", t->options); | |
315 | if (!str) | |
316 | return -ENOMEM; | |
317 | ||
318 | r = mount_option_mangle(str, MS_NODEV|MS_STRICTATIME, &flags, &o); | |
319 | if (r < 0) | |
320 | return r; | |
321 | ||
322 | ro = !!(flags & MS_RDONLY); | |
323 | if (ro) | |
324 | flags ^= MS_RDONLY; | |
325 | } | |
326 | ||
327 | *((*p)++) = (MountEntry) { | |
328 | .path_const = t->path, | |
329 | .mode = TMPFS, | |
330 | .read_only = ro, | |
331 | .options_malloc = o, | |
332 | .flags = flags, | |
333 | }; | |
334 | ||
335 | o = NULL; | |
336 | } | |
337 | ||
338 | return 0; | |
339 | } | |
340 | ||
34de407a | 341 | static int append_static_mounts(MountEntry **p, const MountEntry *mounts, unsigned n, bool ignore_protect) { |
f471b2af | 342 | unsigned i; |
11a30cec DH |
343 | |
344 | assert(p); | |
f471b2af | 345 | assert(mounts); |
11a30cec | 346 | |
5327c910 | 347 | /* Adds a list of static pre-defined entries */ |
f471b2af | 348 | |
5327c910 | 349 | for (i = 0; i < n; i++) |
34de407a LP |
350 | *((*p)++) = (MountEntry) { |
351 | .path_const = mount_entry_path(mounts+i), | |
5327c910 LP |
352 | .mode = mounts[i].mode, |
353 | .ignore = mounts[i].ignore || ignore_protect, | |
354 | }; | |
f471b2af DH |
355 | |
356 | return 0; | |
357 | } | |
358 | ||
34de407a | 359 | static int append_protect_home(MountEntry **p, ProtectHome protect_home, bool ignore_protect) { |
c575770b DH |
360 | assert(p); |
361 | ||
5327c910 | 362 | switch (protect_home) { |
b6c432ca | 363 | |
5327c910 | 364 | case PROTECT_HOME_NO: |
b6c432ca DH |
365 | return 0; |
366 | ||
b6c432ca | 367 | case PROTECT_HOME_READ_ONLY: |
5327c910 LP |
368 | return append_static_mounts(p, protect_home_read_only_table, ELEMENTSOF(protect_home_read_only_table), ignore_protect); |
369 | ||
e4da7d8c YW |
370 | case PROTECT_HOME_TMPFS: |
371 | return append_static_mounts(p, protect_home_tmpfs_table, ELEMENTSOF(protect_home_tmpfs_table), ignore_protect); | |
372 | ||
b6c432ca | 373 | case PROTECT_HOME_YES: |
5327c910 LP |
374 | return append_static_mounts(p, protect_home_yes_table, ELEMENTSOF(protect_home_yes_table), ignore_protect); |
375 | ||
b6c432ca | 376 | default: |
5327c910 | 377 | assert_not_reached("Unexpected ProtectHome= value"); |
b6c432ca | 378 | } |
b6c432ca DH |
379 | } |
380 | ||
34de407a | 381 | static int append_protect_system(MountEntry **p, ProtectSystem protect_system, bool ignore_protect) { |
f471b2af DH |
382 | assert(p); |
383 | ||
5327c910 LP |
384 | switch (protect_system) { |
385 | ||
386 | case PROTECT_SYSTEM_NO: | |
f471b2af DH |
387 | return 0; |
388 | ||
f471b2af | 389 | case PROTECT_SYSTEM_STRICT: |
5327c910 LP |
390 | return append_static_mounts(p, protect_system_strict_table, ELEMENTSOF(protect_system_strict_table), ignore_protect); |
391 | ||
f471b2af | 392 | case PROTECT_SYSTEM_YES: |
5327c910 LP |
393 | return append_static_mounts(p, protect_system_yes_table, ELEMENTSOF(protect_system_yes_table), ignore_protect); |
394 | ||
f471b2af | 395 | case PROTECT_SYSTEM_FULL: |
5327c910 LP |
396 | return append_static_mounts(p, protect_system_full_table, ELEMENTSOF(protect_system_full_table), ignore_protect); |
397 | ||
f471b2af | 398 | default: |
5327c910 | 399 | assert_not_reached("Unexpected ProtectSystem= value"); |
f471b2af | 400 | } |
11a30cec DH |
401 | } |
402 | ||
c17ec25e | 403 | static int mount_path_compare(const void *a, const void *b) { |
34de407a | 404 | const MountEntry *p = a, *q = b; |
a0827e2b | 405 | int d; |
15ae422b | 406 | |
6ee1a919 | 407 | /* If the paths are not equal, then order prefixes first */ |
34de407a | 408 | d = path_compare(mount_entry_path(p), mount_entry_path(q)); |
6ee1a919 LP |
409 | if (d != 0) |
410 | return d; | |
15ae422b | 411 | |
6ee1a919 LP |
412 | /* If the paths are equal, check the mode */ |
413 | if (p->mode < q->mode) | |
414 | return -1; | |
6ee1a919 LP |
415 | if (p->mode > q->mode) |
416 | return 1; | |
15ae422b | 417 | |
6ee1a919 | 418 | return 0; |
15ae422b LP |
419 | } |
420 | ||
34de407a | 421 | static int prefix_where_needed(MountEntry *m, unsigned n, const char *root_directory) { |
5327c910 LP |
422 | unsigned i; |
423 | ||
424 | /* Prefixes all paths in the bind mount table with the root directory if it is specified and the entry needs | |
425 | * that. */ | |
426 | ||
427 | if (!root_directory) | |
428 | return 0; | |
429 | ||
430 | for (i = 0; i < n; i++) { | |
431 | char *s; | |
432 | ||
433 | if (m[i].has_prefix) | |
434 | continue; | |
435 | ||
34de407a | 436 | s = prefix_root(root_directory, mount_entry_path(m+i)); |
5327c910 LP |
437 | if (!s) |
438 | return -ENOMEM; | |
439 | ||
e282f51f | 440 | free_and_replace(m[i].path_malloc, s); |
5327c910 LP |
441 | m[i].has_prefix = true; |
442 | } | |
443 | ||
444 | return 0; | |
445 | } | |
446 | ||
34de407a LP |
447 | static void drop_duplicates(MountEntry *m, unsigned *n) { |
448 | MountEntry *f, *t, *previous; | |
15ae422b | 449 | |
c17ec25e | 450 | assert(m); |
15ae422b | 451 | assert(n); |
15ae422b | 452 | |
fe3c2583 LP |
453 | /* Drops duplicate entries. Expects that the array is properly ordered already. */ |
454 | ||
1d54cd5d | 455 | for (f = m, t = m, previous = NULL; f < m + *n; f++) { |
15ae422b | 456 | |
fe3c2583 | 457 | /* The first one wins (which is the one with the more restrictive mode), see mount_path_compare() |
088696fe LP |
458 | * above. Note that we only drop duplicates that haven't been mounted yet. */ |
459 | if (previous && | |
460 | path_equal(mount_entry_path(f), mount_entry_path(previous)) && | |
461 | !f->applied && !previous->applied) { | |
34de407a LP |
462 | log_debug("%s is duplicate.", mount_entry_path(f)); |
463 | previous->read_only = previous->read_only || mount_entry_read_only(f); /* Propagate the read-only flag to the remaining entry */ | |
1eb7e08e | 464 | mount_entry_done(f); |
15ae422b | 465 | continue; |
fe3c2583 | 466 | } |
15ae422b | 467 | |
e2d7c1a0 | 468 | *t = *f; |
15ae422b | 469 | previous = t; |
fe3c2583 LP |
470 | t++; |
471 | } | |
472 | ||
473 | *n = t - m; | |
474 | } | |
475 | ||
34de407a LP |
476 | static void drop_inaccessible(MountEntry *m, unsigned *n) { |
477 | MountEntry *f, *t; | |
fe3c2583 LP |
478 | const char *clear = NULL; |
479 | ||
480 | assert(m); | |
481 | assert(n); | |
482 | ||
483 | /* Drops all entries obstructed by another entry further up the tree. Expects that the array is properly | |
484 | * ordered already. */ | |
485 | ||
1d54cd5d | 486 | for (f = m, t = m; f < m + *n; f++) { |
fe3c2583 LP |
487 | |
488 | /* If we found a path set for INACCESSIBLE earlier, and this entry has it as prefix we should drop | |
489 | * it, as inaccessible paths really should drop the entire subtree. */ | |
34de407a LP |
490 | if (clear && path_startswith(mount_entry_path(f), clear)) { |
491 | log_debug("%s is masked by %s.", mount_entry_path(f), clear); | |
1eb7e08e | 492 | mount_entry_done(f); |
fe3c2583 LP |
493 | continue; |
494 | } | |
15ae422b | 495 | |
34de407a | 496 | clear = f->mode == INACCESSIBLE ? mount_entry_path(f) : NULL; |
fe3c2583 LP |
497 | |
498 | *t = *f; | |
15ae422b LP |
499 | t++; |
500 | } | |
501 | ||
c17ec25e | 502 | *n = t - m; |
15ae422b LP |
503 | } |
504 | ||
34de407a LP |
505 | static void drop_nop(MountEntry *m, unsigned *n) { |
506 | MountEntry *f, *t; | |
7648a565 LP |
507 | |
508 | assert(m); | |
509 | assert(n); | |
510 | ||
511 | /* Drops all entries which have an immediate parent that has the same type, as they are redundant. Assumes the | |
512 | * list is ordered by prefixes. */ | |
513 | ||
1d54cd5d | 514 | for (f = m, t = m; f < m + *n; f++) { |
7648a565 LP |
515 | |
516 | /* Only suppress such subtrees for READONLY and READWRITE entries */ | |
517 | if (IN_SET(f->mode, READONLY, READWRITE)) { | |
34de407a | 518 | MountEntry *p; |
7648a565 LP |
519 | bool found = false; |
520 | ||
521 | /* Now let's find the first parent of the entry we are looking at. */ | |
522 | for (p = t-1; p >= m; p--) { | |
34de407a | 523 | if (path_startswith(mount_entry_path(f), mount_entry_path(p))) { |
7648a565 LP |
524 | found = true; |
525 | break; | |
526 | } | |
527 | } | |
528 | ||
529 | /* We found it, let's see if it's the same mode, if so, we can drop this entry */ | |
530 | if (found && p->mode == f->mode) { | |
34de407a | 531 | log_debug("%s is redundant by %s", mount_entry_path(f), mount_entry_path(p)); |
1eb7e08e | 532 | mount_entry_done(f); |
7648a565 LP |
533 | continue; |
534 | } | |
535 | } | |
536 | ||
537 | *t = *f; | |
538 | t++; | |
539 | } | |
540 | ||
541 | *n = t - m; | |
542 | } | |
543 | ||
34de407a LP |
544 | static void drop_outside_root(const char *root_directory, MountEntry *m, unsigned *n) { |
545 | MountEntry *f, *t; | |
cd2902c9 LP |
546 | |
547 | assert(m); | |
548 | assert(n); | |
549 | ||
1d54cd5d | 550 | /* Nothing to do */ |
cd2902c9 LP |
551 | if (!root_directory) |
552 | return; | |
553 | ||
554 | /* Drops all mounts that are outside of the root directory. */ | |
555 | ||
1d54cd5d | 556 | for (f = m, t = m; f < m + *n; f++) { |
cd2902c9 | 557 | |
34de407a LP |
558 | if (!path_startswith(mount_entry_path(f), root_directory)) { |
559 | log_debug("%s is outside of root directory.", mount_entry_path(f)); | |
1eb7e08e | 560 | mount_entry_done(f); |
cd2902c9 LP |
561 | continue; |
562 | } | |
563 | ||
564 | *t = *f; | |
565 | t++; | |
566 | } | |
567 | ||
568 | *n = t - m; | |
569 | } | |
570 | ||
16498617 | 571 | static int clone_device_node(const char *d, const char *temporary_mount, bool *make_devnode) { |
6f7f3a33 | 572 | const char *dn; |
b5e99f23 ДГ |
573 | struct stat st; |
574 | int r; | |
575 | ||
414b304b | 576 | if (stat(d, &st) < 0) { |
b5e99f23 | 577 | if (errno == ENOENT) |
af984e13 | 578 | return -ENXIO; |
b5e99f23 ДГ |
579 | return -errno; |
580 | } | |
581 | ||
582 | if (!S_ISBLK(st.st_mode) && | |
583 | !S_ISCHR(st.st_mode)) | |
584 | return -EINVAL; | |
585 | ||
586 | if (st.st_rdev == 0) | |
af984e13 | 587 | return -ENXIO; |
b5e99f23 | 588 | |
6f7f3a33 | 589 | dn = strjoina(temporary_mount, d); |
b5e99f23 | 590 | |
16498617 CB |
591 | if (*make_devnode) { |
592 | mac_selinux_create_file_prepare(d, st.st_mode); | |
593 | r = mknod(dn, st.st_mode, st.st_rdev); | |
594 | mac_selinux_create_file_clear(); | |
595 | ||
596 | if (r == 0) | |
af984e13 | 597 | return 0; |
16498617 CB |
598 | if (errno != EPERM) |
599 | return log_debug_errno(errno, "mknod failed for %s: %m", d); | |
600 | ||
601 | *make_devnode = false; | |
602 | } | |
603 | ||
604 | /* We're about to fallback to bind-mounting the device | |
605 | * node. So create a dummy bind-mount target. */ | |
606 | mac_selinux_create_file_prepare(d, 0); | |
607 | r = mknod(dn, S_IFREG, 0); | |
b5e99f23 | 608 | mac_selinux_create_file_clear(); |
b5e99f23 | 609 | |
16498617 CB |
610 | if (r < 0 && errno != EEXIST) |
611 | return log_debug_errno(errno, "mknod fallback failed for %s: %m", d); | |
612 | ||
613 | /* Fallback to bind-mounting: | |
614 | * The assumption here is that all used device nodes carry standard | |
615 | * properties. Specifically, the devices nodes we bind-mount should | |
616 | * either be owned by root:root or root:tty (e.g. /dev/tty, /dev/ptmx) | |
617 | * and should not carry ACLs. */ | |
618 | if (mount(d, dn, NULL, MS_BIND, NULL) < 0) | |
619 | return log_debug_errno(errno, "mount failed for %s: %m", d); | |
b5e99f23 | 620 | |
af984e13 | 621 | return 0; |
b5e99f23 ДГ |
622 | } |
623 | ||
5d997827 | 624 | static int mount_private_dev(MountEntry *m) { |
7f112f50 LP |
625 | static const char devnodes[] = |
626 | "/dev/null\0" | |
627 | "/dev/zero\0" | |
628 | "/dev/full\0" | |
629 | "/dev/random\0" | |
630 | "/dev/urandom\0" | |
631 | "/dev/tty\0"; | |
632 | ||
2b85f4e1 | 633 | char temporary_mount[] = "/tmp/namespace-dev-XXXXXX"; |
63cc4c31 | 634 | const char *d, *dev = NULL, *devpts = NULL, *devshm = NULL, *devhugepages = NULL, *devmqueue = NULL, *devlog = NULL, *devptmx = NULL; |
16498617 | 635 | bool can_mknod = true; |
7f112f50 LP |
636 | _cleanup_umask_ mode_t u; |
637 | int r; | |
638 | ||
639 | assert(m); | |
640 | ||
641 | u = umask(0000); | |
642 | ||
2b85f4e1 LP |
643 | if (!mkdtemp(temporary_mount)) |
644 | return -errno; | |
645 | ||
63c372cb | 646 | dev = strjoina(temporary_mount, "/dev"); |
dc751688 | 647 | (void) mkdir(dev, 0755); |
737ba3c8 | 648 | if (mount("tmpfs", dev, "tmpfs", DEV_MOUNT_OPTIONS, "mode=755") < 0) { |
2b85f4e1 LP |
649 | r = -errno; |
650 | goto fail; | |
651 | } | |
652 | ||
63c372cb | 653 | devpts = strjoina(temporary_mount, "/dev/pts"); |
dc751688 | 654 | (void) mkdir(devpts, 0755); |
2b85f4e1 LP |
655 | if (mount("/dev/pts", devpts, NULL, MS_BIND, NULL) < 0) { |
656 | r = -errno; | |
657 | goto fail; | |
658 | } | |
659 | ||
414b304b ДГ |
660 | /* /dev/ptmx can either be a device node or a symlink to /dev/pts/ptmx |
661 | * when /dev/ptmx a device node, /dev/pts/ptmx has 000 permissions making it inaccessible | |
662 | * thus, in that case make a clone | |
663 | * | |
664 | * in nspawn and other containers it will be a symlink, in that case make it a symlink | |
665 | */ | |
36ce7110 LP |
666 | r = is_symlink("/dev/ptmx"); |
667 | if (r < 0) | |
3164e3cb | 668 | goto fail; |
36ce7110 | 669 | if (r > 0) { |
414b304b ДГ |
670 | devptmx = strjoina(temporary_mount, "/dev/ptmx"); |
671 | if (symlink("pts/ptmx", devptmx) < 0) { | |
672 | r = -errno; | |
673 | goto fail; | |
674 | } | |
675 | } else { | |
16498617 | 676 | r = clone_device_node("/dev/ptmx", temporary_mount, &can_mknod); |
152c475f LP |
677 | if (r < 0) |
678 | goto fail; | |
414b304b | 679 | } |
e06b6479 | 680 | |
63c372cb | 681 | devshm = strjoina(temporary_mount, "/dev/shm"); |
8d953682 | 682 | (void) mkdir(devshm, 0755); |
2b85f4e1 LP |
683 | r = mount("/dev/shm", devshm, NULL, MS_BIND, NULL); |
684 | if (r < 0) { | |
685 | r = -errno; | |
686 | goto fail; | |
687 | } | |
688 | ||
63c372cb | 689 | devmqueue = strjoina(temporary_mount, "/dev/mqueue"); |
dc751688 | 690 | (void) mkdir(devmqueue, 0755); |
3164e3cb | 691 | (void) mount("/dev/mqueue", devmqueue, NULL, MS_BIND, NULL); |
2b85f4e1 | 692 | |
63c372cb | 693 | devhugepages = strjoina(temporary_mount, "/dev/hugepages"); |
dc751688 | 694 | (void) mkdir(devhugepages, 0755); |
3164e3cb | 695 | (void) mount("/dev/hugepages", devhugepages, NULL, MS_BIND, NULL); |
2b85f4e1 | 696 | |
63c372cb | 697 | devlog = strjoina(temporary_mount, "/dev/log"); |
3164e3cb | 698 | (void) symlink("/run/systemd/journal/dev-log", devlog); |
82d25240 | 699 | |
7f112f50 | 700 | NULSTR_FOREACH(d, devnodes) { |
16498617 | 701 | r = clone_device_node(d, temporary_mount, &can_mknod); |
af984e13 ZJS |
702 | /* ENXIO means the the *source* is not a device file, skip creation in that case */ |
703 | if (r < 0 && r != -ENXIO) | |
2b85f4e1 | 704 | goto fail; |
7f112f50 LP |
705 | } |
706 | ||
03cfe0d5 | 707 | dev_setup(temporary_mount, UID_INVALID, GID_INVALID); |
7f112f50 | 708 | |
ee818b89 AC |
709 | /* Create the /dev directory if missing. It is more likely to be |
710 | * missing when the service is started with RootDirectory. This is | |
711 | * consistent with mount units creating the mount points when missing. | |
712 | */ | |
34de407a | 713 | (void) mkdir_p_label(mount_entry_path(m), 0755); |
ee818b89 | 714 | |
9e5f8252 | 715 | /* Unmount everything in old /dev */ |
34de407a LP |
716 | umount_recursive(mount_entry_path(m), 0); |
717 | if (mount(dev, mount_entry_path(m), NULL, MS_MOVE, NULL) < 0) { | |
2b85f4e1 LP |
718 | r = -errno; |
719 | goto fail; | |
720 | } | |
7f112f50 | 721 | |
2b85f4e1 LP |
722 | rmdir(dev); |
723 | rmdir(temporary_mount); | |
7f112f50 | 724 | |
2b85f4e1 | 725 | return 0; |
7f112f50 | 726 | |
2b85f4e1 LP |
727 | fail: |
728 | if (devpts) | |
729 | umount(devpts); | |
7f112f50 | 730 | |
2b85f4e1 LP |
731 | if (devshm) |
732 | umount(devshm); | |
7f112f50 | 733 | |
2b85f4e1 LP |
734 | if (devhugepages) |
735 | umount(devhugepages); | |
7f112f50 | 736 | |
2b85f4e1 LP |
737 | if (devmqueue) |
738 | umount(devmqueue); | |
7f112f50 | 739 | |
d267c5aa ZJS |
740 | umount(dev); |
741 | rmdir(dev); | |
2b85f4e1 | 742 | rmdir(temporary_mount); |
7f112f50 | 743 | |
2b85f4e1 | 744 | return r; |
7f112f50 LP |
745 | } |
746 | ||
2a2969fd | 747 | static int mount_bind_dev(const MountEntry *m) { |
5d997827 LP |
748 | int r; |
749 | ||
750 | assert(m); | |
751 | ||
752 | /* Implements the little brother of mount_private_dev(): simply bind mounts the host's /dev into the service's | |
753 | * /dev. This is only used when RootDirectory= is set. */ | |
754 | ||
645767d6 LP |
755 | (void) mkdir_p_label(mount_entry_path(m), 0755); |
756 | ||
5d997827 LP |
757 | r = path_is_mount_point(mount_entry_path(m), NULL, 0); |
758 | if (r < 0) | |
759 | return log_debug_errno(r, "Unable to determine whether /dev is already mounted: %m"); | |
760 | if (r > 0) /* make this a NOP if /dev is already a mount point */ | |
761 | return 0; | |
762 | ||
763 | if (mount("/dev", mount_entry_path(m), NULL, MS_BIND|MS_REC, NULL) < 0) | |
764 | return log_debug_errno(errno, "Failed to bind mount %s: %m", mount_entry_path(m)); | |
765 | ||
766 | return 1; | |
767 | } | |
768 | ||
2a2969fd | 769 | static int mount_sysfs(const MountEntry *m) { |
5d997827 LP |
770 | int r; |
771 | ||
772 | assert(m); | |
773 | ||
645767d6 LP |
774 | (void) mkdir_p_label(mount_entry_path(m), 0755); |
775 | ||
5d997827 LP |
776 | r = path_is_mount_point(mount_entry_path(m), NULL, 0); |
777 | if (r < 0) | |
778 | return log_debug_errno(r, "Unable to determine whether /sys is already mounted: %m"); | |
779 | if (r > 0) /* make this a NOP if /sys is already a mount point */ | |
780 | return 0; | |
781 | ||
782 | /* Bind mount the host's version so that we get all child mounts of it, too. */ | |
783 | if (mount("/sys", mount_entry_path(m), NULL, MS_BIND|MS_REC, NULL) < 0) | |
784 | return log_debug_errno(errno, "Failed to mount %s: %m", mount_entry_path(m)); | |
785 | ||
786 | return 1; | |
787 | } | |
788 | ||
2a2969fd | 789 | static int mount_procfs(const MountEntry *m) { |
5d997827 LP |
790 | int r; |
791 | ||
792 | assert(m); | |
793 | ||
645767d6 LP |
794 | (void) mkdir_p_label(mount_entry_path(m), 0755); |
795 | ||
5d997827 LP |
796 | r = path_is_mount_point(mount_entry_path(m), NULL, 0); |
797 | if (r < 0) | |
798 | return log_debug_errno(r, "Unable to determine whether /proc is already mounted: %m"); | |
799 | if (r > 0) /* make this a NOP if /proc is already a mount point */ | |
800 | return 0; | |
801 | ||
802 | /* Mount a new instance, so that we get the one that matches our user namespace, if we are running in one */ | |
803 | if (mount("proc", mount_entry_path(m), "proc", MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL) < 0) | |
804 | return log_debug_errno(errno, "Failed to mount %s: %m", mount_entry_path(m)); | |
805 | ||
806 | return 1; | |
807 | } | |
808 | ||
2abd4e38 | 809 | static int mount_tmpfs(const MountEntry *m) { |
6c47cd7d LP |
810 | assert(m); |
811 | ||
2abd4e38 | 812 | /* First, get rid of everything that is below if there is anything. Then, overmount with our new tmpfs */ |
6c47cd7d LP |
813 | |
814 | (void) mkdir_p_label(mount_entry_path(m), 0755); | |
815 | (void) umount_recursive(mount_entry_path(m), 0); | |
816 | ||
2abd4e38 | 817 | if (mount("tmpfs", mount_entry_path(m), "tmpfs", m->flags, mount_entry_options(m)) < 0) |
6c47cd7d LP |
818 | return log_debug_errno(errno, "Failed to mount %s: %m", mount_entry_path(m)); |
819 | ||
820 | return 1; | |
821 | } | |
822 | ||
088696fe | 823 | static int follow_symlink( |
d2d6c096 | 824 | const char *root_directory, |
088696fe | 825 | MountEntry *m) { |
d2d6c096 | 826 | |
088696fe | 827 | _cleanup_free_ char *target = NULL; |
8fceda93 LP |
828 | int r; |
829 | ||
088696fe LP |
830 | /* Let's chase symlinks, but only one step at a time. That's because depending where the symlink points we |
831 | * might need to change the order in which we mount stuff. Hence: let's normalize piecemeal, and do one step at | |
832 | * a time by specifying CHASE_STEP. This function returns 0 if we resolved one step, and > 0 if we reached the | |
833 | * end and already have a fully normalized name. */ | |
8fceda93 | 834 | |
088696fe LP |
835 | r = chase_symlinks(mount_entry_path(m), root_directory, CHASE_STEP|CHASE_NONEXISTENT, &target); |
836 | if (r < 0) | |
837 | return log_debug_errno(r, "Failed to chase symlinks '%s': %m", mount_entry_path(m)); | |
838 | if (r > 0) /* Reached the end, nothing more to resolve */ | |
839 | return 1; | |
8fceda93 | 840 | |
088696fe LP |
841 | if (m->n_followed >= CHASE_SYMLINKS_MAX) { /* put a boundary on things */ |
842 | log_debug("Symlink loop on '%s'.", mount_entry_path(m)); | |
843 | return -ELOOP; | |
8fceda93 | 844 | } |
8fceda93 | 845 | |
088696fe | 846 | log_debug("Followed mount entry path symlink %s → %s.", mount_entry_path(m), target); |
8fceda93 | 847 | |
088696fe LP |
848 | free_and_replace(m->path_malloc, target); |
849 | m->has_prefix = true; | |
8fceda93 | 850 | |
088696fe LP |
851 | m->n_followed ++; |
852 | ||
853 | return 0; | |
8fceda93 LP |
854 | } |
855 | ||
ac0930c8 | 856 | static int apply_mount( |
8fceda93 | 857 | const char *root_directory, |
89bd586c | 858 | MountEntry *m) { |
ac0930c8 | 859 | |
a227a4be | 860 | bool rbind = true, make = false; |
15ae422b | 861 | const char *what; |
15ae422b | 862 | int r; |
15ae422b | 863 | |
c17ec25e | 864 | assert(m); |
15ae422b | 865 | |
34de407a | 866 | log_debug("Applying namespace mount on %s", mount_entry_path(m)); |
fe3c2583 | 867 | |
c17ec25e | 868 | switch (m->mode) { |
15ae422b | 869 | |
160cfdbe LP |
870 | case INACCESSIBLE: { |
871 | struct stat target; | |
6d313367 LP |
872 | |
873 | /* First, get rid of everything that is below if there | |
874 | * is anything... Then, overmount it with an | |
c4b41707 | 875 | * inaccessible path. */ |
34de407a | 876 | (void) umount_recursive(mount_entry_path(m), 0); |
6d313367 | 877 | |
088696fe LP |
878 | if (lstat(mount_entry_path(m), &target) < 0) { |
879 | if (errno == ENOENT && m->ignore) | |
880 | return 0; | |
881 | ||
34de407a | 882 | return log_debug_errno(errno, "Failed to lstat() %s to determine what to mount over it: %m", mount_entry_path(m)); |
088696fe | 883 | } |
15ae422b | 884 | |
c4b41707 | 885 | what = mode_to_inaccessible_node(target.st_mode); |
5fd7cf6f LP |
886 | if (!what) { |
887 | log_debug("File type not supported for inaccessible mounts. Note that symlinks are not allowed"); | |
c4b41707 AP |
888 | return -ELOOP; |
889 | } | |
890 | break; | |
160cfdbe | 891 | } |
fe3c2583 | 892 | |
15ae422b | 893 | case READONLY: |
15ae422b | 894 | case READWRITE: |
8fceda93 | 895 | r = path_is_mount_point(mount_entry_path(m), root_directory, 0); |
088696fe LP |
896 | if (r == -ENOENT && m->ignore) |
897 | return 0; | |
d944dc95 | 898 | if (r < 0) |
34de407a | 899 | return log_debug_errno(r, "Failed to determine whether %s is already a mount point: %m", mount_entry_path(m)); |
6b7c9f8b LP |
900 | if (r > 0) /* Nothing to do here, it is already a mount. We just later toggle the MS_RDONLY bit for the mount point if needed. */ |
901 | return 0; | |
6b7c9f8b | 902 | /* This isn't a mount point yet, let's make it one. */ |
34de407a | 903 | what = mount_entry_path(m); |
6b7c9f8b | 904 | break; |
15ae422b | 905 | |
d2d6c096 LP |
906 | case BIND_MOUNT: |
907 | rbind = false; | |
d2d6c096 | 908 | |
4831981d | 909 | _fallthrough_; |
088696fe LP |
910 | case BIND_MOUNT_RECURSIVE: { |
911 | _cleanup_free_ char *chased = NULL; | |
5d997827 | 912 | |
088696fe LP |
913 | /* Since mount() will always follow symlinks we chase the symlinks on our own first. Note that bind |
914 | * mount source paths are always relative to the host root, hence we pass NULL as root directory to | |
915 | * chase_symlinks() here. */ | |
916 | ||
917 | r = chase_symlinks(mount_entry_source(m), NULL, CHASE_TRAIL_SLASH, &chased); | |
918 | if (r == -ENOENT && m->ignore) { | |
919 | log_debug_errno(r, "Path %s does not exist, ignoring.", mount_entry_source(m)); | |
920 | return 0; | |
921 | } | |
922 | if (r < 0) | |
923 | return log_debug_errno(r, "Failed to follow symlinks on %s: %m", mount_entry_source(m)); | |
924 | ||
925 | log_debug("Followed source symlinks %s → %s.", mount_entry_source(m), chased); | |
926 | ||
927 | free_and_replace(m->source_malloc, chased); | |
d2d6c096 LP |
928 | |
929 | what = mount_entry_source(m); | |
a227a4be | 930 | make = true; |
d2d6c096 | 931 | break; |
088696fe | 932 | } |
d2d6c096 | 933 | |
6c47cd7d | 934 | case EMPTY_DIR: |
2abd4e38 YW |
935 | case TMPFS: |
936 | return mount_tmpfs(m); | |
6c47cd7d | 937 | |
ac0930c8 | 938 | case PRIVATE_TMP: |
89bd586c | 939 | what = mount_entry_source(m); |
a227a4be | 940 | make = true; |
15ae422b | 941 | break; |
e364ad06 | 942 | |
d6797c92 | 943 | case PRIVATE_DEV: |
5d997827 LP |
944 | return mount_private_dev(m); |
945 | ||
946 | case BIND_DEV: | |
947 | return mount_bind_dev(m); | |
948 | ||
949 | case SYSFS: | |
950 | return mount_sysfs(m); | |
951 | ||
952 | case PROCFS: | |
953 | return mount_procfs(m); | |
d6797c92 | 954 | |
e364ad06 LP |
955 | default: |
956 | assert_not_reached("Unknown mode"); | |
15ae422b LP |
957 | } |
958 | ||
ac0930c8 | 959 | assert(what); |
15ae422b | 960 | |
a227a4be LP |
961 | if (mount(what, mount_entry_path(m), NULL, MS_BIND|(rbind ? MS_REC : 0), NULL) < 0) { |
962 | bool try_again = false; | |
963 | r = -errno; | |
964 | ||
965 | if (r == -ENOENT && make) { | |
966 | struct stat st; | |
967 | ||
968 | /* Hmm, either the source or the destination are missing. Let's see if we can create the destination, then try again */ | |
969 | ||
e8717862 LP |
970 | if (stat(what, &st) < 0) |
971 | log_debug_errno(errno, "Mount point source '%s' is not accessible: %m", what); | |
972 | else { | |
973 | int q; | |
a227a4be LP |
974 | |
975 | (void) mkdir_parents(mount_entry_path(m), 0755); | |
976 | ||
977 | if (S_ISDIR(st.st_mode)) | |
e8717862 | 978 | q = mkdir(mount_entry_path(m), 0755) < 0 ? -errno : 0; |
a227a4be | 979 | else |
e8717862 LP |
980 | q = touch(mount_entry_path(m)); |
981 | ||
982 | if (q < 0) | |
983 | log_debug_errno(q, "Failed to create destination mount point node '%s': %m", mount_entry_path(m)); | |
984 | else | |
985 | try_again = true; | |
a227a4be LP |
986 | } |
987 | } | |
988 | ||
989 | if (try_again) { | |
990 | if (mount(what, mount_entry_path(m), NULL, MS_BIND|(rbind ? MS_REC : 0), NULL) < 0) | |
991 | r = -errno; | |
992 | else | |
993 | r = 0; | |
994 | } | |
995 | ||
996 | if (r < 0) | |
997 | return log_debug_errno(r, "Failed to mount %s to %s: %m", what, mount_entry_path(m)); | |
998 | } | |
6b7c9f8b | 999 | |
34de407a | 1000 | log_debug("Successfully mounted %s to %s", what, mount_entry_path(m)); |
6b7c9f8b | 1001 | return 0; |
ac0930c8 | 1002 | } |
15ae422b | 1003 | |
2a2969fd | 1004 | static int make_read_only(const MountEntry *m, char **blacklist, FILE *proc_self_mountinfo) { |
6b7c9f8b | 1005 | int r = 0; |
15ae422b | 1006 | |
c17ec25e | 1007 | assert(m); |
ac9de0b3 | 1008 | assert(proc_self_mountinfo); |
ac0930c8 | 1009 | |
2abd4e38 YW |
1010 | if (mount_entry_read_only(m)) { |
1011 | if (IN_SET(m->mode, EMPTY_DIR, TMPFS)) { | |
1012 | /* Make superblock readonly */ | |
1013 | if (mount(NULL, mount_entry_path(m), NULL, MS_REMOUNT | MS_RDONLY | m->flags, mount_entry_options(m)) < 0) | |
1014 | r = -errno; | |
1015 | } else | |
1016 | r = bind_remount_recursive_with_mountinfo(mount_entry_path(m), true, blacklist, proc_self_mountinfo); | |
1017 | } else if (m->mode == PRIVATE_DEV) { | |
1018 | /* Superblock can be readonly but the submounts can't */ | |
34de407a | 1019 | if (mount(NULL, mount_entry_path(m), NULL, MS_REMOUNT|DEV_MOUNT_OPTIONS|MS_RDONLY, NULL) < 0) |
6b7c9f8b | 1020 | r = -errno; |
737ba3c8 | 1021 | } else |
6b7c9f8b LP |
1022 | return 0; |
1023 | ||
1024 | /* Not that we only turn on the MS_RDONLY flag here, we never turn it off. Something that was marked read-only | |
1025 | * already stays this way. This improves compatibility with container managers, where we won't attempt to undo | |
1026 | * read-only mounts already applied. */ | |
ac0930c8 | 1027 | |
8fceda93 LP |
1028 | if (r == -ENOENT && m->ignore) |
1029 | r = 0; | |
5327c910 | 1030 | |
1d54cd5d | 1031 | return r; |
d944dc95 LP |
1032 | } |
1033 | ||
bb0ff3fb | 1034 | static bool namespace_info_mount_apivfs(const char *root_directory, const NamespaceInfo *ns_info) { |
5d997827 LP |
1035 | assert(ns_info); |
1036 | ||
9c988f93 DH |
1037 | /* |
1038 | * ProtectControlGroups= and ProtectKernelTunables= imply MountAPIVFS=, | |
1039 | * since to protect the API VFS mounts, they need to be around in the | |
1040 | * first place... and RootDirectory= or RootImage= need to be set. | |
1041 | */ | |
5d997827 | 1042 | |
9c988f93 DH |
1043 | /* root_directory should point to a mount point */ |
1044 | return root_directory && | |
1045 | (ns_info->mount_apivfs || | |
1046 | ns_info->protect_control_groups || | |
1047 | ns_info->protect_kernel_tunables); | |
5d997827 LP |
1048 | } |
1049 | ||
2652c6c1 | 1050 | static unsigned namespace_calculate_mounts( |
9c988f93 | 1051 | const char* root_directory, |
bb0ff3fb | 1052 | const NamespaceInfo *ns_info, |
2652c6c1 DH |
1053 | char** read_write_paths, |
1054 | char** read_only_paths, | |
1055 | char** inaccessible_paths, | |
6c47cd7d | 1056 | char** empty_directories, |
d2d6c096 | 1057 | unsigned n_bind_mounts, |
2abd4e38 | 1058 | unsigned n_temporary_filesystems, |
2652c6c1 DH |
1059 | const char* tmp_dir, |
1060 | const char* var_tmp_dir, | |
2652c6c1 DH |
1061 | ProtectHome protect_home, |
1062 | ProtectSystem protect_system) { | |
1063 | ||
b6c432ca | 1064 | unsigned protect_home_cnt; |
f471b2af DH |
1065 | unsigned protect_system_cnt = |
1066 | (protect_system == PROTECT_SYSTEM_STRICT ? | |
1067 | ELEMENTSOF(protect_system_strict_table) : | |
1068 | ((protect_system == PROTECT_SYSTEM_FULL) ? | |
1069 | ELEMENTSOF(protect_system_full_table) : | |
1070 | ((protect_system == PROTECT_SYSTEM_YES) ? | |
1071 | ELEMENTSOF(protect_system_yes_table) : 0))); | |
1072 | ||
b6c432ca DH |
1073 | protect_home_cnt = |
1074 | (protect_home == PROTECT_HOME_YES ? | |
1075 | ELEMENTSOF(protect_home_yes_table) : | |
1076 | ((protect_home == PROTECT_HOME_READ_ONLY) ? | |
e4da7d8c YW |
1077 | ELEMENTSOF(protect_home_read_only_table) : |
1078 | ((protect_home == PROTECT_HOME_TMPFS) ? | |
1079 | ELEMENTSOF(protect_home_tmpfs_table) : 0))); | |
b6c432ca | 1080 | |
2652c6c1 DH |
1081 | return !!tmp_dir + !!var_tmp_dir + |
1082 | strv_length(read_write_paths) + | |
1083 | strv_length(read_only_paths) + | |
1084 | strv_length(inaccessible_paths) + | |
6c47cd7d | 1085 | strv_length(empty_directories) + |
d2d6c096 | 1086 | n_bind_mounts + |
2abd4e38 | 1087 | n_temporary_filesystems + |
c575770b DH |
1088 | ns_info->private_dev + |
1089 | (ns_info->protect_kernel_tunables ? ELEMENTSOF(protect_kernel_tunables_table) : 0) + | |
1090 | (ns_info->protect_control_groups ? 1 : 0) + | |
1091 | (ns_info->protect_kernel_modules ? ELEMENTSOF(protect_kernel_modules_table) : 0) + | |
5d997827 | 1092 | protect_home_cnt + protect_system_cnt + |
9c988f93 | 1093 | (namespace_info_mount_apivfs(root_directory, ns_info) ? ELEMENTSOF(apivfs_table) : 0); |
2652c6c1 DH |
1094 | } |
1095 | ||
f8b64b57 LP |
1096 | static void normalize_mounts(const char *root_directory, MountEntry *mounts, unsigned *n_mounts) { |
1097 | assert(n_mounts); | |
1098 | assert(mounts || *n_mounts == 0); | |
1099 | ||
1100 | qsort_safe(mounts, *n_mounts, sizeof(MountEntry), mount_path_compare); | |
1101 | ||
1102 | drop_duplicates(mounts, n_mounts); | |
1103 | drop_outside_root(root_directory, mounts, n_mounts); | |
1104 | drop_inaccessible(mounts, n_mounts); | |
1105 | drop_nop(mounts, n_mounts); | |
1106 | } | |
1107 | ||
613b411c | 1108 | int setup_namespace( |
ee818b89 | 1109 | const char* root_directory, |
915e6d16 | 1110 | const char* root_image, |
bb0ff3fb | 1111 | const NamespaceInfo *ns_info, |
2a624c36 AP |
1112 | char** read_write_paths, |
1113 | char** read_only_paths, | |
1114 | char** inaccessible_paths, | |
6c47cd7d | 1115 | char** empty_directories, |
d2d6c096 LP |
1116 | const BindMount *bind_mounts, |
1117 | unsigned n_bind_mounts, | |
2abd4e38 YW |
1118 | const TemporaryFileSystem *temporary_filesystems, |
1119 | unsigned n_temporary_filesystems, | |
a004cb4c LP |
1120 | const char* tmp_dir, |
1121 | const char* var_tmp_dir, | |
1b8689f9 LP |
1122 | ProtectHome protect_home, |
1123 | ProtectSystem protect_system, | |
915e6d16 LP |
1124 | unsigned long mount_flags, |
1125 | DissectImageFlags dissect_image_flags) { | |
15ae422b | 1126 | |
915e6d16 | 1127 | _cleanup_(loop_device_unrefp) LoopDevice *loop_device = NULL; |
78ebe980 | 1128 | _cleanup_(decrypted_image_unrefp) DecryptedImage *decrypted_image = NULL; |
915e6d16 | 1129 | _cleanup_(dissected_image_unrefp) DissectedImage *dissected_image = NULL; |
78ebe980 | 1130 | _cleanup_free_ void *root_hash = NULL; |
34de407a | 1131 | MountEntry *m, *mounts = NULL; |
78ebe980 | 1132 | size_t root_hash_size = 0; |
d944dc95 | 1133 | bool make_slave = false; |
e908468b | 1134 | const char *root; |
f0a4feb0 | 1135 | unsigned n_mounts; |
d18aff04 | 1136 | bool require_prefix = false; |
c17ec25e | 1137 | int r = 0; |
15ae422b | 1138 | |
915e6d16 LP |
1139 | assert(ns_info); |
1140 | ||
613b411c | 1141 | if (mount_flags == 0) |
c17ec25e | 1142 | mount_flags = MS_SHARED; |
ac0930c8 | 1143 | |
915e6d16 LP |
1144 | if (root_image) { |
1145 | dissect_image_flags |= DISSECT_IMAGE_REQUIRE_ROOT; | |
1146 | ||
c9ef8573 LP |
1147 | if (protect_system == PROTECT_SYSTEM_STRICT && |
1148 | protect_home != PROTECT_HOME_NO && | |
1149 | strv_isempty(read_write_paths)) | |
915e6d16 LP |
1150 | dissect_image_flags |= DISSECT_IMAGE_READ_ONLY; |
1151 | ||
1152 | r = loop_device_make_by_path(root_image, | |
1153 | dissect_image_flags & DISSECT_IMAGE_READ_ONLY ? O_RDONLY : O_RDWR, | |
1154 | &loop_device); | |
1155 | if (r < 0) | |
1156 | return r; | |
1157 | ||
78ebe980 LP |
1158 | r = root_hash_load(root_image, &root_hash, &root_hash_size); |
1159 | if (r < 0) | |
1160 | return r; | |
1161 | ||
1162 | r = dissect_image(loop_device->fd, root_hash, root_hash_size, dissect_image_flags, &dissected_image); | |
1163 | if (r < 0) | |
1164 | return r; | |
1165 | ||
1166 | r = dissected_image_decrypt(dissected_image, NULL, root_hash, root_hash_size, dissect_image_flags, &decrypted_image); | |
915e6d16 LP |
1167 | if (r < 0) |
1168 | return r; | |
915e6d16 LP |
1169 | } |
1170 | ||
e908468b LP |
1171 | if (root_directory) |
1172 | root = root_directory; | |
2abd4e38 | 1173 | else if (root_image || n_bind_mounts > 0 || n_temporary_filesystems > 0) { |
e908468b LP |
1174 | |
1175 | /* If we are booting from an image, create a mount point for the image, if it's still missing. We use | |
1176 | * the same mount point for all images, which is safe, since they all live in their own namespaces | |
1177 | * after all, and hence won't see each other. We also use such a root directory whenever there are bind | |
1178 | * mounts configured, so that their source mounts are never obstructed by mounts we already applied | |
1179 | * while we are applying them. */ | |
1180 | ||
1181 | root = "/run/systemd/unit-root"; | |
1182 | (void) mkdir_label(root, 0700); | |
d18aff04 | 1183 | require_prefix = true; |
e908468b LP |
1184 | } else |
1185 | root = NULL; | |
1186 | ||
cfbeb4ef | 1187 | n_mounts = namespace_calculate_mounts( |
e908468b | 1188 | root, |
cfbeb4ef LP |
1189 | ns_info, |
1190 | read_write_paths, | |
1191 | read_only_paths, | |
1192 | inaccessible_paths, | |
6c47cd7d | 1193 | empty_directories, |
f5c52a77 | 1194 | n_bind_mounts, |
2abd4e38 | 1195 | n_temporary_filesystems, |
cfbeb4ef LP |
1196 | tmp_dir, var_tmp_dir, |
1197 | protect_home, protect_system); | |
613b411c | 1198 | |
2652c6c1 | 1199 | /* Set mount slave mode */ |
e908468b | 1200 | if (root || n_mounts > 0) |
d944dc95 LP |
1201 | make_slave = true; |
1202 | ||
f0a4feb0 | 1203 | if (n_mounts > 0) { |
34de407a | 1204 | m = mounts = (MountEntry *) alloca0(n_mounts * sizeof(MountEntry)); |
d18aff04 | 1205 | r = append_access_mounts(&m, read_write_paths, READWRITE, require_prefix); |
613b411c | 1206 | if (r < 0) |
f0a4feb0 | 1207 | goto finish; |
613b411c | 1208 | |
d18aff04 | 1209 | r = append_access_mounts(&m, read_only_paths, READONLY, require_prefix); |
613b411c | 1210 | if (r < 0) |
f0a4feb0 | 1211 | goto finish; |
613b411c | 1212 | |
d18aff04 | 1213 | r = append_access_mounts(&m, inaccessible_paths, INACCESSIBLE, require_prefix); |
613b411c | 1214 | if (r < 0) |
f0a4feb0 | 1215 | goto finish; |
7ff7394d | 1216 | |
6c47cd7d LP |
1217 | r = append_empty_dir_mounts(&m, empty_directories); |
1218 | if (r < 0) | |
1219 | goto finish; | |
1220 | ||
d2d6c096 LP |
1221 | r = append_bind_mounts(&m, bind_mounts, n_bind_mounts); |
1222 | if (r < 0) | |
1223 | goto finish; | |
1224 | ||
2abd4e38 YW |
1225 | r = append_tmpfs_mounts(&m, temporary_filesystems, n_temporary_filesystems); |
1226 | if (r < 0) | |
1227 | goto finish; | |
1228 | ||
613b411c | 1229 | if (tmp_dir) { |
34de407a | 1230 | *(m++) = (MountEntry) { |
5327c910 LP |
1231 | .path_const = "/tmp", |
1232 | .mode = PRIVATE_TMP, | |
89bd586c | 1233 | .source_const = tmp_dir, |
5327c910 | 1234 | }; |
613b411c | 1235 | } |
7ff7394d | 1236 | |
613b411c | 1237 | if (var_tmp_dir) { |
34de407a | 1238 | *(m++) = (MountEntry) { |
5327c910 | 1239 | .path_const = "/var/tmp", |
89bd586c YW |
1240 | .mode = PRIVATE_TMP, |
1241 | .source_const = var_tmp_dir, | |
5327c910 | 1242 | }; |
7ff7394d | 1243 | } |
ac0930c8 | 1244 | |
c575770b | 1245 | if (ns_info->private_dev) { |
34de407a | 1246 | *(m++) = (MountEntry) { |
5327c910 LP |
1247 | .path_const = "/dev", |
1248 | .mode = PRIVATE_DEV, | |
1249 | }; | |
7f112f50 LP |
1250 | } |
1251 | ||
c575770b | 1252 | if (ns_info->protect_kernel_tunables) { |
5327c910 | 1253 | r = append_static_mounts(&m, protect_kernel_tunables_table, ELEMENTSOF(protect_kernel_tunables_table), ns_info->ignore_protect_paths); |
c575770b | 1254 | if (r < 0) |
f0a4feb0 | 1255 | goto finish; |
c575770b DH |
1256 | } |
1257 | ||
1258 | if (ns_info->protect_kernel_modules) { | |
5327c910 | 1259 | r = append_static_mounts(&m, protect_kernel_modules_table, ELEMENTSOF(protect_kernel_modules_table), ns_info->ignore_protect_paths); |
c575770b | 1260 | if (r < 0) |
f0a4feb0 | 1261 | goto finish; |
c575770b | 1262 | } |
59eeb84b | 1263 | |
c575770b | 1264 | if (ns_info->protect_control_groups) { |
34de407a | 1265 | *(m++) = (MountEntry) { |
5327c910 LP |
1266 | .path_const = "/sys/fs/cgroup", |
1267 | .mode = READONLY, | |
1268 | }; | |
59eeb84b LP |
1269 | } |
1270 | ||
5327c910 | 1271 | r = append_protect_home(&m, protect_home, ns_info->ignore_protect_paths); |
b6c432ca | 1272 | if (r < 0) |
f0a4feb0 | 1273 | goto finish; |
417116f2 | 1274 | |
5327c910 | 1275 | r = append_protect_system(&m, protect_system, false); |
f471b2af | 1276 | if (r < 0) |
f0a4feb0 | 1277 | goto finish; |
417116f2 | 1278 | |
e908468b | 1279 | if (namespace_info_mount_apivfs(root, ns_info)) { |
5d997827 LP |
1280 | r = append_static_mounts(&m, apivfs_table, ELEMENTSOF(apivfs_table), ns_info->ignore_protect_paths); |
1281 | if (r < 0) | |
1282 | goto finish; | |
1283 | } | |
1284 | ||
f0a4feb0 | 1285 | assert(mounts + n_mounts == m); |
ac0930c8 | 1286 | |
5327c910 | 1287 | /* Prepend the root directory where that's necessary */ |
e908468b | 1288 | r = prefix_where_needed(mounts, n_mounts, root); |
5327c910 LP |
1289 | if (r < 0) |
1290 | goto finish; | |
1291 | ||
f8b64b57 | 1292 | normalize_mounts(root_directory, mounts, &n_mounts); |
15ae422b LP |
1293 | } |
1294 | ||
d944dc95 LP |
1295 | if (unshare(CLONE_NEWNS) < 0) { |
1296 | r = -errno; | |
1297 | goto finish; | |
1298 | } | |
1e4e94c8 | 1299 | |
d944dc95 | 1300 | if (make_slave) { |
c2c13f2d LP |
1301 | /* Remount / as SLAVE so that nothing now mounted in the namespace |
1302 | shows up in the parent */ | |
d944dc95 LP |
1303 | if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) { |
1304 | r = -errno; | |
1305 | goto finish; | |
1306 | } | |
ee818b89 AC |
1307 | } |
1308 | ||
915e6d16 | 1309 | if (root_image) { |
e908468b | 1310 | /* A root image is specified, mount it to the right place */ |
2d3a5a73 | 1311 | r = dissected_image_mount(dissected_image, root, UID_INVALID, dissect_image_flags); |
915e6d16 LP |
1312 | if (r < 0) |
1313 | goto finish; | |
1314 | ||
07ce7407 TM |
1315 | if (decrypted_image) { |
1316 | r = decrypted_image_relinquish(decrypted_image); | |
1317 | if (r < 0) | |
1318 | goto finish; | |
1319 | } | |
78ebe980 | 1320 | |
915e6d16 LP |
1321 | loop_device_relinquish(loop_device); |
1322 | ||
1323 | } else if (root_directory) { | |
1324 | ||
e908468b LP |
1325 | /* A root directory is specified. Turn its directory into bind mount, if it isn't one yet. */ |
1326 | r = path_is_mount_point(root, NULL, AT_SYMLINK_FOLLOW); | |
8f1ad200 | 1327 | if (r < 0) |
d944dc95 | 1328 | goto finish; |
8f1ad200 | 1329 | if (r == 0) { |
e908468b | 1330 | if (mount(root, root, NULL, MS_BIND|MS_REC, NULL) < 0) { |
8f1ad200 LP |
1331 | r = -errno; |
1332 | goto finish; | |
1333 | } | |
d944dc95 | 1334 | } |
e908468b LP |
1335 | |
1336 | } else if (root) { | |
1337 | ||
1338 | /* Let's mount the main root directory to the root directory to use */ | |
1339 | if (mount("/", root, NULL, MS_BIND|MS_REC, NULL) < 0) { | |
1340 | r = -errno; | |
1341 | goto finish; | |
1342 | } | |
ee818b89 | 1343 | } |
c2c13f2d | 1344 | |
4e0c20de LP |
1345 | /* Try to set up the new root directory before mounting anything else there. */ |
1346 | if (root_image || root_directory) | |
1347 | (void) base_filesystem_create(root, UID_INVALID, GID_INVALID); | |
1348 | ||
f0a4feb0 | 1349 | if (n_mounts > 0) { |
ac9de0b3 | 1350 | _cleanup_fclose_ FILE *proc_self_mountinfo = NULL; |
6b7c9f8b LP |
1351 | char **blacklist; |
1352 | unsigned j; | |
1353 | ||
ac9de0b3 TR |
1354 | /* Open /proc/self/mountinfo now as it may become unavailable if we mount anything on top of /proc. |
1355 | * For example, this is the case with the option: 'InaccessiblePaths=/proc' */ | |
1356 | proc_self_mountinfo = fopen("/proc/self/mountinfo", "re"); | |
1357 | if (!proc_self_mountinfo) { | |
1358 | r = -errno; | |
1359 | goto finish; | |
1360 | } | |
1361 | ||
088696fe LP |
1362 | /* First round, establish all mounts we need */ |
1363 | for (;;) { | |
1364 | bool again = false; | |
1365 | ||
1366 | for (m = mounts; m < mounts + n_mounts; ++m) { | |
1367 | ||
1368 | if (m->applied) | |
1369 | continue; | |
1370 | ||
1371 | r = follow_symlink(root, m); | |
1372 | if (r < 0) | |
1373 | goto finish; | |
1374 | if (r == 0) { | |
1375 | /* We hit a symlinked mount point. The entry got rewritten and might point to a | |
1376 | * very different place now. Let's normalize the changed list, and start from | |
1377 | * the beginning. After all to mount the entry at the new location we might | |
1378 | * need some other mounts first */ | |
1379 | again = true; | |
1380 | break; | |
1381 | } | |
1382 | ||
1383 | r = apply_mount(root, m); | |
1384 | if (r < 0) | |
1385 | goto finish; | |
1386 | ||
1387 | m->applied = true; | |
1388 | } | |
1389 | ||
1390 | if (!again) | |
1391 | break; | |
1392 | ||
1393 | normalize_mounts(root_directory, mounts, &n_mounts); | |
c2c13f2d | 1394 | } |
15ae422b | 1395 | |
6b7c9f8b | 1396 | /* Create a blacklist we can pass to bind_mount_recursive() */ |
f0a4feb0 DH |
1397 | blacklist = newa(char*, n_mounts+1); |
1398 | for (j = 0; j < n_mounts; j++) | |
34de407a | 1399 | blacklist[j] = (char*) mount_entry_path(mounts+j); |
6b7c9f8b LP |
1400 | blacklist[j] = NULL; |
1401 | ||
1402 | /* Second round, flip the ro bits if necessary. */ | |
f0a4feb0 | 1403 | for (m = mounts; m < mounts + n_mounts; ++m) { |
ac9de0b3 | 1404 | r = make_read_only(m, blacklist, proc_self_mountinfo); |
c2c13f2d | 1405 | if (r < 0) |
d944dc95 | 1406 | goto finish; |
c2c13f2d | 1407 | } |
15ae422b LP |
1408 | } |
1409 | ||
e908468b | 1410 | if (root) { |
ee818b89 | 1411 | /* MS_MOVE does not work on MS_SHARED so the remount MS_SHARED will be done later */ |
e908468b | 1412 | r = mount_move_root(root); |
d944dc95 LP |
1413 | if (r < 0) |
1414 | goto finish; | |
ee818b89 AC |
1415 | } |
1416 | ||
55fe7432 | 1417 | /* Remount / as the desired mode. Note that this will not |
c2c13f2d LP |
1418 | * reestablish propagation from our side to the host, since |
1419 | * what's disconnected is disconnected. */ | |
d944dc95 LP |
1420 | if (mount(NULL, "/", NULL, mount_flags | MS_REC, NULL) < 0) { |
1421 | r = -errno; | |
1422 | goto finish; | |
1423 | } | |
15ae422b | 1424 | |
d944dc95 | 1425 | r = 0; |
15ae422b | 1426 | |
d944dc95 | 1427 | finish: |
f0a4feb0 | 1428 | for (m = mounts; m < mounts + n_mounts; m++) |
1eb7e08e | 1429 | mount_entry_done(m); |
613b411c LP |
1430 | |
1431 | return r; | |
1432 | } | |
1433 | ||
d2d6c096 LP |
1434 | void bind_mount_free_many(BindMount *b, unsigned n) { |
1435 | unsigned i; | |
1436 | ||
1437 | assert(b || n == 0); | |
1438 | ||
1439 | for (i = 0; i < n; i++) { | |
1440 | free(b[i].source); | |
1441 | free(b[i].destination); | |
1442 | } | |
1443 | ||
1444 | free(b); | |
1445 | } | |
1446 | ||
1447 | int bind_mount_add(BindMount **b, unsigned *n, const BindMount *item) { | |
1448 | _cleanup_free_ char *s = NULL, *d = NULL; | |
1449 | BindMount *c; | |
1450 | ||
1451 | assert(b); | |
1452 | assert(n); | |
1453 | assert(item); | |
1454 | ||
1455 | s = strdup(item->source); | |
1456 | if (!s) | |
1457 | return -ENOMEM; | |
1458 | ||
1459 | d = strdup(item->destination); | |
1460 | if (!d) | |
1461 | return -ENOMEM; | |
1462 | ||
aa484f35 | 1463 | c = reallocarray(*b, *n + 1, sizeof(BindMount)); |
d2d6c096 LP |
1464 | if (!c) |
1465 | return -ENOMEM; | |
1466 | ||
1467 | *b = c; | |
1468 | ||
1469 | c[(*n) ++] = (BindMount) { | |
1cc6c93a YW |
1470 | .source = TAKE_PTR(s), |
1471 | .destination = TAKE_PTR(d), | |
d2d6c096 LP |
1472 | .read_only = item->read_only, |
1473 | .recursive = item->recursive, | |
1474 | .ignore_enoent = item->ignore_enoent, | |
1475 | }; | |
1476 | ||
d2d6c096 LP |
1477 | return 0; |
1478 | } | |
1479 | ||
2abd4e38 YW |
1480 | void temporary_filesystem_free_many(TemporaryFileSystem *t, unsigned n) { |
1481 | unsigned i; | |
1482 | ||
1483 | assert(t || n == 0); | |
1484 | ||
1485 | for (i = 0; i < n; i++) { | |
1486 | free(t[i].path); | |
1487 | free(t[i].options); | |
1488 | } | |
1489 | ||
1490 | free(t); | |
1491 | } | |
1492 | ||
1493 | int temporary_filesystem_add( | |
1494 | TemporaryFileSystem **t, | |
1495 | unsigned *n, | |
1496 | const char *path, | |
1497 | const char *options) { | |
1498 | ||
1499 | _cleanup_free_ char *p = NULL, *o = NULL; | |
1500 | TemporaryFileSystem *c; | |
1501 | ||
1502 | assert(t); | |
1503 | assert(n); | |
1504 | assert(path); | |
1505 | ||
1506 | p = strdup(path); | |
1507 | if (!p) | |
1508 | return -ENOMEM; | |
1509 | ||
1510 | if (!isempty(options)) { | |
1511 | o = strdup(options); | |
1512 | if (!o) | |
1513 | return -ENOMEM; | |
1514 | } | |
1515 | ||
aa484f35 | 1516 | c = reallocarray(*t, *n + 1, sizeof(TemporaryFileSystem)); |
2abd4e38 YW |
1517 | if (!c) |
1518 | return -ENOMEM; | |
1519 | ||
1520 | *t = c; | |
1521 | ||
1522 | c[(*n) ++] = (TemporaryFileSystem) { | |
1cc6c93a YW |
1523 | .path = TAKE_PTR(p), |
1524 | .options = TAKE_PTR(o), | |
2abd4e38 YW |
1525 | }; |
1526 | ||
2abd4e38 YW |
1527 | return 0; |
1528 | } | |
1529 | ||
613b411c LP |
1530 | static int setup_one_tmp_dir(const char *id, const char *prefix, char **path) { |
1531 | _cleanup_free_ char *x = NULL; | |
6b46ea73 LP |
1532 | char bid[SD_ID128_STRING_MAX]; |
1533 | sd_id128_t boot_id; | |
1534 | int r; | |
613b411c LP |
1535 | |
1536 | assert(id); | |
1537 | assert(prefix); | |
1538 | assert(path); | |
1539 | ||
6b46ea73 LP |
1540 | /* We include the boot id in the directory so that after a |
1541 | * reboot we can easily identify obsolete directories. */ | |
1542 | ||
1543 | r = sd_id128_get_boot(&boot_id); | |
1544 | if (r < 0) | |
1545 | return r; | |
1546 | ||
605405c6 | 1547 | x = strjoin(prefix, "/systemd-private-", sd_id128_to_string(boot_id, bid), "-", id, "-XXXXXX"); |
613b411c LP |
1548 | if (!x) |
1549 | return -ENOMEM; | |
1550 | ||
1551 | RUN_WITH_UMASK(0077) | |
1552 | if (!mkdtemp(x)) | |
1553 | return -errno; | |
1554 | ||
1555 | RUN_WITH_UMASK(0000) { | |
1556 | char *y; | |
1557 | ||
63c372cb | 1558 | y = strjoina(x, "/tmp"); |
613b411c LP |
1559 | |
1560 | if (mkdir(y, 0777 | S_ISVTX) < 0) | |
1561 | return -errno; | |
c17ec25e | 1562 | } |
15ae422b | 1563 | |
1cc6c93a | 1564 | *path = TAKE_PTR(x); |
613b411c LP |
1565 | |
1566 | return 0; | |
1567 | } | |
1568 | ||
1569 | int setup_tmp_dirs(const char *id, char **tmp_dir, char **var_tmp_dir) { | |
1570 | char *a, *b; | |
1571 | int r; | |
1572 | ||
1573 | assert(id); | |
1574 | assert(tmp_dir); | |
1575 | assert(var_tmp_dir); | |
1576 | ||
1577 | r = setup_one_tmp_dir(id, "/tmp", &a); | |
1578 | if (r < 0) | |
1579 | return r; | |
1580 | ||
1581 | r = setup_one_tmp_dir(id, "/var/tmp", &b); | |
1582 | if (r < 0) { | |
1583 | char *t; | |
1584 | ||
63c372cb | 1585 | t = strjoina(a, "/tmp"); |
613b411c LP |
1586 | rmdir(t); |
1587 | rmdir(a); | |
1588 | ||
1589 | free(a); | |
1590 | return r; | |
1591 | } | |
1592 | ||
1593 | *tmp_dir = a; | |
1594 | *var_tmp_dir = b; | |
1595 | ||
1596 | return 0; | |
1597 | } | |
1598 | ||
1599 | int setup_netns(int netns_storage_socket[2]) { | |
1600 | _cleanup_close_ int netns = -1; | |
3ee897d6 | 1601 | int r, q; |
613b411c LP |
1602 | |
1603 | assert(netns_storage_socket); | |
1604 | assert(netns_storage_socket[0] >= 0); | |
1605 | assert(netns_storage_socket[1] >= 0); | |
1606 | ||
1607 | /* We use the passed socketpair as a storage buffer for our | |
76cd584b LP |
1608 | * namespace reference fd. Whatever process runs this first |
1609 | * shall create a new namespace, all others should just join | |
1610 | * it. To serialize that we use a file lock on the socket | |
1611 | * pair. | |
613b411c LP |
1612 | * |
1613 | * It's a bit crazy, but hey, works great! */ | |
1614 | ||
1615 | if (lockf(netns_storage_socket[0], F_LOCK, 0) < 0) | |
1616 | return -errno; | |
1617 | ||
3ee897d6 LP |
1618 | netns = receive_one_fd(netns_storage_socket[0], MSG_DONTWAIT); |
1619 | if (netns == -EAGAIN) { | |
613b411c LP |
1620 | /* Nothing stored yet, so let's create a new namespace */ |
1621 | ||
1622 | if (unshare(CLONE_NEWNET) < 0) { | |
1623 | r = -errno; | |
1624 | goto fail; | |
1625 | } | |
1626 | ||
1627 | loopback_setup(); | |
1628 | ||
1629 | netns = open("/proc/self/ns/net", O_RDONLY|O_CLOEXEC|O_NOCTTY); | |
1630 | if (netns < 0) { | |
1631 | r = -errno; | |
1632 | goto fail; | |
1633 | } | |
1634 | ||
1635 | r = 1; | |
613b411c | 1636 | |
3ee897d6 LP |
1637 | } else if (netns < 0) { |
1638 | r = netns; | |
1639 | goto fail; | |
613b411c | 1640 | |
3ee897d6 LP |
1641 | } else { |
1642 | /* Yay, found something, so let's join the namespace */ | |
613b411c LP |
1643 | if (setns(netns, CLONE_NEWNET) < 0) { |
1644 | r = -errno; | |
1645 | goto fail; | |
1646 | } | |
1647 | ||
1648 | r = 0; | |
1649 | } | |
1650 | ||
3ee897d6 LP |
1651 | q = send_one_fd(netns_storage_socket[1], netns, MSG_DONTWAIT); |
1652 | if (q < 0) { | |
1653 | r = q; | |
613b411c LP |
1654 | goto fail; |
1655 | } | |
1656 | ||
1657 | fail: | |
fe048ce5 | 1658 | (void) lockf(netns_storage_socket[0], F_ULOCK, 0); |
15ae422b LP |
1659 | return r; |
1660 | } | |
417116f2 | 1661 | |
6e2d7c4f MS |
1662 | bool ns_type_supported(NamespaceType type) { |
1663 | const char *t, *ns_proc; | |
1664 | ||
0fa5b831 LP |
1665 | t = namespace_type_to_string(type); |
1666 | if (!t) /* Don't know how to translate this? Then it's not supported */ | |
6e2d7c4f MS |
1667 | return false; |
1668 | ||
6e2d7c4f | 1669 | ns_proc = strjoina("/proc/self/ns/", t); |
6e2d7c4f MS |
1670 | return access(ns_proc, F_OK) == 0; |
1671 | } | |
1672 | ||
1b8689f9 LP |
1673 | static const char *const protect_home_table[_PROTECT_HOME_MAX] = { |
1674 | [PROTECT_HOME_NO] = "no", | |
1675 | [PROTECT_HOME_YES] = "yes", | |
1676 | [PROTECT_HOME_READ_ONLY] = "read-only", | |
e4da7d8c | 1677 | [PROTECT_HOME_TMPFS] = "tmpfs", |
417116f2 LP |
1678 | }; |
1679 | ||
1b8689f9 LP |
1680 | DEFINE_STRING_TABLE_LOOKUP(protect_home, ProtectHome); |
1681 | ||
5e1c6154 YW |
1682 | ProtectHome parse_protect_home_or_bool(const char *s) { |
1683 | int r; | |
1684 | ||
1685 | r = parse_boolean(s); | |
1686 | if (r > 0) | |
1687 | return PROTECT_HOME_YES; | |
1688 | if (r == 0) | |
1689 | return PROTECT_HOME_NO; | |
1690 | ||
1691 | return protect_home_from_string(s); | |
1692 | } | |
1693 | ||
1b8689f9 LP |
1694 | static const char *const protect_system_table[_PROTECT_SYSTEM_MAX] = { |
1695 | [PROTECT_SYSTEM_NO] = "no", | |
1696 | [PROTECT_SYSTEM_YES] = "yes", | |
1697 | [PROTECT_SYSTEM_FULL] = "full", | |
3f815163 | 1698 | [PROTECT_SYSTEM_STRICT] = "strict", |
1b8689f9 LP |
1699 | }; |
1700 | ||
1701 | DEFINE_STRING_TABLE_LOOKUP(protect_system, ProtectSystem); | |
6e2d7c4f | 1702 | |
03c791aa YW |
1703 | ProtectSystem parse_protect_system_or_bool(const char *s) { |
1704 | int r; | |
1705 | ||
1706 | r = parse_boolean(s); | |
1707 | if (r > 0) | |
1708 | return PROTECT_SYSTEM_YES; | |
1709 | if (r == 0) | |
1710 | return PROTECT_SYSTEM_NO; | |
1711 | ||
1712 | return protect_system_from_string(s); | |
1713 | } | |
1714 | ||
6e2d7c4f MS |
1715 | static const char* const namespace_type_table[] = { |
1716 | [NAMESPACE_MOUNT] = "mnt", | |
1717 | [NAMESPACE_CGROUP] = "cgroup", | |
1718 | [NAMESPACE_UTS] = "uts", | |
1719 | [NAMESPACE_IPC] = "ipc", | |
1720 | [NAMESPACE_USER] = "user", | |
1721 | [NAMESPACE_PID] = "pid", | |
1722 | [NAMESPACE_NET] = "net", | |
1723 | }; | |
1724 | ||
1725 | DEFINE_STRING_TABLE_LOOKUP(namespace_type, NamespaceType); |