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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
15ae422b LP |
2 | |
3 | #include <errno.h> | |
e08f94ac | 4 | #include <linux/loop.h> |
07630cea | 5 | #include <sched.h> |
15ae422b | 6 | #include <stdio.h> |
07630cea | 7 | #include <sys/mount.h> |
07630cea | 8 | #include <unistd.h> |
25e870b5 | 9 | #include <linux/fs.h> |
15ae422b | 10 | |
b5efdb8a | 11 | #include "alloc-util.h" |
10404d52 | 12 | #include "base-filesystem.h" |
7f112f50 | 13 | #include "dev-setup.h" |
3ffd4af2 | 14 | #include "fd-util.h" |
e5f10caf | 15 | #include "format-util.h" |
d944dc95 | 16 | #include "fs-util.h" |
e908468b | 17 | #include "label.h" |
915e6d16 | 18 | #include "loop-util.h" |
07630cea | 19 | #include "loopback-setup.h" |
07630cea | 20 | #include "mkdir.h" |
4349cd7c | 21 | #include "mount-util.h" |
049af8ad | 22 | #include "mountpoint-util.h" |
0cb8e3d1 | 23 | #include "namespace-util.h" |
3ffd4af2 | 24 | #include "namespace.h" |
d8b4d14d | 25 | #include "nulstr-util.h" |
07630cea | 26 | #include "path-util.h" |
d7b8eec7 | 27 | #include "selinux-util.h" |
2583fbea | 28 | #include "socket-util.h" |
760877e9 | 29 | #include "sort-util.h" |
36ce7110 | 30 | #include "stat-util.h" |
8b43440b | 31 | #include "string-table.h" |
07630cea LP |
32 | #include "string-util.h" |
33 | #include "strv.h" | |
a652f050 | 34 | #include "tmpfile-util.h" |
affb60b1 | 35 | #include "umask-util.h" |
ee104e11 | 36 | #include "user-util.h" |
15ae422b | 37 | |
737ba3c8 | 38 | #define DEV_MOUNT_OPTIONS (MS_NOSUID|MS_STRICTATIME|MS_NOEXEC) |
39 | ||
c17ec25e | 40 | typedef enum MountMode { |
15ae422b LP |
41 | /* This is ordered by priority! */ |
42 | INACCESSIBLE, | |
d2d6c096 LP |
43 | BIND_MOUNT, |
44 | BIND_MOUNT_RECURSIVE, | |
ac0930c8 | 45 | PRIVATE_TMP, |
56a13a49 | 46 | PRIVATE_TMP_READONLY, |
7f112f50 | 47 | PRIVATE_DEV, |
5d997827 | 48 | BIND_DEV, |
6c47cd7d | 49 | EMPTY_DIR, |
5d997827 LP |
50 | SYSFS, |
51 | PROCFS, | |
52 | READONLY, | |
59eeb84b | 53 | READWRITE, |
2abd4e38 | 54 | TMPFS, |
1e05071d | 55 | READWRITE_IMPLICIT, /* Should have the lowest priority. */ |
5beb8688 | 56 | _MOUNT_MODE_MAX, |
c17ec25e | 57 | } MountMode; |
15ae422b | 58 | |
34de407a | 59 | typedef struct MountEntry { |
5327c910 | 60 | const char *path_const; /* Memory allocated on stack or static */ |
cfbeb4ef | 61 | MountMode mode:5; |
5327c910 LP |
62 | bool ignore:1; /* Ignore if path does not exist? */ |
63 | bool has_prefix:1; /* Already is prefixed by the root dir? */ | |
cfbeb4ef | 64 | bool read_only:1; /* Shall this mount point be read-only? */ |
9ce4e4b0 | 65 | bool nosuid:1; /* Shall set MS_NOSUID on the mount itself */ |
088696fe | 66 | bool applied:1; /* Already applied */ |
55fe7432 | 67 | char *path_malloc; /* Use this instead of 'path_const' if we had to allocate memory */ |
d2d6c096 LP |
68 | const char *source_const; /* The source path, for bind mounts */ |
69 | char *source_malloc; | |
2abd4e38 YW |
70 | const char *options_const;/* Mount options for tmpfs */ |
71 | char *options_malloc; | |
72 | unsigned long flags; /* Mount flags used by EMPTY_DIR and TMPFS. Do not include MS_RDONLY here, but please use read_only. */ | |
088696fe | 73 | unsigned n_followed; |
34de407a | 74 | } MountEntry; |
15ae422b | 75 | |
5d997827 | 76 | /* If MountAPIVFS= is used, let's mount /sys and /proc into the it, but only as a fallback if the user hasn't mounted |
3fe91079 | 77 | * something there already. These mounts are hence overridden by any other explicitly configured mounts. */ |
5d997827 LP |
78 | static const MountEntry apivfs_table[] = { |
79 | { "/proc", PROCFS, false }, | |
80 | { "/dev", BIND_DEV, false }, | |
81 | { "/sys", SYSFS, false }, | |
82 | }; | |
f471b2af | 83 | |
11a30cec | 84 | /* ProtectKernelTunables= option and the related filesystem APIs */ |
34de407a | 85 | static const MountEntry protect_kernel_tunables_table[] = { |
1e05071d YW |
86 | { "/proc/acpi", READONLY, true }, |
87 | { "/proc/apm", READONLY, true }, /* Obsolete API, there's no point in permitting access to this, ever */ | |
88 | { "/proc/asound", READONLY, true }, | |
89 | { "/proc/bus", READONLY, true }, | |
90 | { "/proc/fs", READONLY, true }, | |
91 | { "/proc/irq", READONLY, true }, | |
92 | { "/proc/kallsyms", INACCESSIBLE, true }, | |
93 | { "/proc/kcore", INACCESSIBLE, true }, | |
94 | { "/proc/latency_stats", READONLY, true }, | |
95 | { "/proc/mtrr", READONLY, true }, | |
96 | { "/proc/scsi", READONLY, true }, | |
97 | { "/proc/sys", READONLY, false }, | |
98 | { "/proc/sysrq-trigger", READONLY, true }, | |
99 | { "/proc/timer_stats", READONLY, true }, | |
100 | { "/sys", READONLY, false }, | |
101 | { "/sys/fs/bpf", READONLY, true }, | |
102 | { "/sys/fs/cgroup", READWRITE_IMPLICIT, false }, /* READONLY is set by ProtectControlGroups= option */ | |
103 | { "/sys/fs/selinux", READWRITE_IMPLICIT, true }, | |
104 | { "/sys/kernel/debug", READONLY, true }, | |
105 | { "/sys/kernel/tracing", READONLY, true }, | |
11a30cec DH |
106 | }; |
107 | ||
c575770b | 108 | /* ProtectKernelModules= option */ |
34de407a | 109 | static const MountEntry protect_kernel_modules_table[] = { |
349cc4a5 | 110 | #if HAVE_SPLIT_USR |
c6232fb0 | 111 | { "/lib/modules", INACCESSIBLE, true }, |
c575770b | 112 | #endif |
c6232fb0 | 113 | { "/usr/lib/modules", INACCESSIBLE, true }, |
c575770b DH |
114 | }; |
115 | ||
94a7b275 KK |
116 | /* ProtectKernelLogs= option */ |
117 | static const MountEntry protect_kernel_logs_table[] = { | |
118 | { "/proc/kmsg", INACCESSIBLE, true }, | |
119 | { "/dev/kmsg", INACCESSIBLE, true }, | |
120 | }; | |
121 | ||
b6c432ca DH |
122 | /* |
123 | * ProtectHome=read-only table, protect $HOME and $XDG_RUNTIME_DIR and rest of | |
124 | * system should be protected by ProtectSystem= | |
125 | */ | |
34de407a | 126 | static const MountEntry protect_home_read_only_table[] = { |
c6232fb0 LP |
127 | { "/home", READONLY, true }, |
128 | { "/run/user", READONLY, true }, | |
129 | { "/root", READONLY, true }, | |
b6c432ca DH |
130 | }; |
131 | ||
e4da7d8c YW |
132 | /* ProtectHome=tmpfs table */ |
133 | static const MountEntry protect_home_tmpfs_table[] = { | |
7d85383e TM |
134 | { "/home", TMPFS, true, .read_only = true, .options_const = "mode=0755" TMPFS_LIMITS_EMPTY_OR_ALMOST, .flags = MS_NODEV|MS_STRICTATIME }, |
135 | { "/run/user", TMPFS, true, .read_only = true, .options_const = "mode=0755" TMPFS_LIMITS_EMPTY_OR_ALMOST, .flags = MS_NODEV|MS_STRICTATIME }, | |
136 | { "/root", TMPFS, true, .read_only = true, .options_const = "mode=0700" TMPFS_LIMITS_EMPTY_OR_ALMOST, .flags = MS_NODEV|MS_STRICTATIME }, | |
e4da7d8c YW |
137 | }; |
138 | ||
b6c432ca | 139 | /* ProtectHome=yes table */ |
34de407a | 140 | static const MountEntry protect_home_yes_table[] = { |
c6232fb0 LP |
141 | { "/home", INACCESSIBLE, true }, |
142 | { "/run/user", INACCESSIBLE, true }, | |
143 | { "/root", INACCESSIBLE, true }, | |
b6c432ca DH |
144 | }; |
145 | ||
f471b2af | 146 | /* ProtectSystem=yes table */ |
34de407a | 147 | static const MountEntry protect_system_yes_table[] = { |
c6232fb0 LP |
148 | { "/usr", READONLY, false }, |
149 | { "/boot", READONLY, true }, | |
150 | { "/efi", READONLY, true }, | |
7486f305 AB |
151 | #if HAVE_SPLIT_USR |
152 | { "/lib", READONLY, true }, | |
153 | { "/lib64", READONLY, true }, | |
154 | { "/bin", READONLY, true }, | |
671f0f8d | 155 | # if HAVE_SPLIT_BIN |
7486f305 | 156 | { "/sbin", READONLY, true }, |
671f0f8d | 157 | # endif |
7486f305 | 158 | #endif |
f471b2af DH |
159 | }; |
160 | ||
161 | /* ProtectSystem=full includes ProtectSystem=yes */ | |
34de407a | 162 | static const MountEntry protect_system_full_table[] = { |
c6232fb0 LP |
163 | { "/usr", READONLY, false }, |
164 | { "/boot", READONLY, true }, | |
165 | { "/efi", READONLY, true }, | |
166 | { "/etc", READONLY, false }, | |
7486f305 AB |
167 | #if HAVE_SPLIT_USR |
168 | { "/lib", READONLY, true }, | |
169 | { "/lib64", READONLY, true }, | |
170 | { "/bin", READONLY, true }, | |
671f0f8d | 171 | # if HAVE_SPLIT_BIN |
7486f305 | 172 | { "/sbin", READONLY, true }, |
671f0f8d | 173 | # endif |
7486f305 | 174 | #endif |
f471b2af DH |
175 | }; |
176 | ||
177 | /* | |
178 | * ProtectSystem=strict table. In this strict mode, we mount everything | |
179 | * read-only, except for /proc, /dev, /sys which are the kernel API VFS, | |
180 | * which are left writable, but PrivateDevices= + ProtectKernelTunables= | |
181 | * protect those, and these options should be fully orthogonal. | |
182 | * (And of course /home and friends are also left writable, as ProtectHome= | |
183 | * shall manage those, orthogonally). | |
184 | */ | |
34de407a | 185 | static const MountEntry protect_system_strict_table[] = { |
1e05071d YW |
186 | { "/", READONLY, false }, |
187 | { "/proc", READWRITE_IMPLICIT, false }, /* ProtectKernelTunables= */ | |
188 | { "/sys", READWRITE_IMPLICIT, false }, /* ProtectKernelTunables= */ | |
189 | { "/dev", READWRITE_IMPLICIT, false }, /* PrivateDevices= */ | |
190 | { "/home", READWRITE_IMPLICIT, true }, /* ProtectHome= */ | |
191 | { "/run/user", READWRITE_IMPLICIT, true }, /* ProtectHome= */ | |
192 | { "/root", READWRITE_IMPLICIT, true }, /* ProtectHome= */ | |
f471b2af DH |
193 | }; |
194 | ||
5beb8688 YW |
195 | static const char * const mount_mode_table[_MOUNT_MODE_MAX] = { |
196 | [INACCESSIBLE] = "inaccessible", | |
197 | [BIND_MOUNT] = "bind", | |
198 | [BIND_MOUNT_RECURSIVE] = "rbind", | |
199 | [PRIVATE_TMP] = "private-tmp", | |
200 | [PRIVATE_DEV] = "private-dev", | |
201 | [BIND_DEV] = "bind-dev", | |
202 | [EMPTY_DIR] = "empty", | |
203 | [SYSFS] = "sysfs", | |
204 | [PROCFS] = "procfs", | |
205 | [READONLY] = "read-only", | |
206 | [READWRITE] = "read-write", | |
207 | [TMPFS] = "tmpfs", | |
208 | [READWRITE_IMPLICIT] = "rw-implicit", | |
209 | }; | |
210 | ||
211 | DEFINE_PRIVATE_STRING_TABLE_LOOKUP_TO_STRING(mount_mode, MountMode); | |
212 | ||
34de407a | 213 | static const char *mount_entry_path(const MountEntry *p) { |
f0a4feb0 DH |
214 | assert(p); |
215 | ||
5327c910 LP |
216 | /* Returns the path of this bind mount. If the malloc()-allocated ->path_buffer field is set we return that, |
217 | * otherwise the stack/static ->path field is returned. */ | |
f0a4feb0 | 218 | |
5327c910 | 219 | return p->path_malloc ?: p->path_const; |
f0a4feb0 DH |
220 | } |
221 | ||
34de407a | 222 | static bool mount_entry_read_only(const MountEntry *p) { |
cfbeb4ef LP |
223 | assert(p); |
224 | ||
56a13a49 | 225 | return p->read_only || IN_SET(p->mode, READONLY, INACCESSIBLE, PRIVATE_TMP_READONLY); |
cfbeb4ef LP |
226 | } |
227 | ||
d2d6c096 LP |
228 | static const char *mount_entry_source(const MountEntry *p) { |
229 | assert(p); | |
230 | ||
231 | return p->source_malloc ?: p->source_const; | |
232 | } | |
233 | ||
2abd4e38 YW |
234 | static const char *mount_entry_options(const MountEntry *p) { |
235 | assert(p); | |
236 | ||
237 | return p->options_malloc ?: p->options_const; | |
238 | } | |
239 | ||
1eb7e08e LP |
240 | static void mount_entry_done(MountEntry *p) { |
241 | assert(p); | |
242 | ||
243 | p->path_malloc = mfree(p->path_malloc); | |
244 | p->source_malloc = mfree(p->source_malloc); | |
2abd4e38 | 245 | p->options_malloc = mfree(p->options_malloc); |
1eb7e08e LP |
246 | } |
247 | ||
d18aff04 | 248 | static int append_access_mounts(MountEntry **p, char **strv, MountMode mode, bool forcibly_require_prefix) { |
15ae422b LP |
249 | char **i; |
250 | ||
613b411c LP |
251 | assert(p); |
252 | ||
1e05071d | 253 | /* Adds a list of user-supplied READWRITE/READWRITE_IMPLICIT/READONLY/INACCESSIBLE entries */ |
5327c910 | 254 | |
15ae422b | 255 | STRV_FOREACH(i, strv) { |
5327c910 LP |
256 | bool ignore = false, needs_prefix = false; |
257 | const char *e = *i; | |
15ae422b | 258 | |
5327c910 LP |
259 | /* Look for any prefixes */ |
260 | if (startswith(e, "-")) { | |
261 | e++; | |
9c94d52e | 262 | ignore = true; |
ea92ae33 | 263 | } |
5327c910 LP |
264 | if (startswith(e, "+")) { |
265 | e++; | |
266 | needs_prefix = true; | |
267 | } | |
ea92ae33 | 268 | |
baaa35ad ZJS |
269 | if (!path_is_absolute(e)) |
270 | return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), | |
271 | "Path is not absolute: %s", e); | |
15ae422b | 272 | |
34de407a | 273 | *((*p)++) = (MountEntry) { |
5327c910 LP |
274 | .path_const = e, |
275 | .mode = mode, | |
276 | .ignore = ignore, | |
d18aff04 | 277 | .has_prefix = !needs_prefix && !forcibly_require_prefix, |
5327c910 | 278 | }; |
15ae422b LP |
279 | } |
280 | ||
281 | return 0; | |
282 | } | |
283 | ||
6c47cd7d LP |
284 | static int append_empty_dir_mounts(MountEntry **p, char **strv) { |
285 | char **i; | |
286 | ||
287 | assert(p); | |
288 | ||
289 | /* Adds tmpfs mounts to provide readable but empty directories. This is primarily used to implement the | |
290 | * "/private/" boundary directories for DynamicUser=1. */ | |
291 | ||
292 | STRV_FOREACH(i, strv) { | |
293 | ||
294 | *((*p)++) = (MountEntry) { | |
295 | .path_const = *i, | |
296 | .mode = EMPTY_DIR, | |
297 | .ignore = false, | |
6c47cd7d | 298 | .read_only = true, |
7d85383e | 299 | .options_const = "mode=755" TMPFS_LIMITS_EMPTY_OR_ALMOST, |
2abd4e38 | 300 | .flags = MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_STRICTATIME, |
6c47cd7d LP |
301 | }; |
302 | } | |
303 | ||
304 | return 0; | |
305 | } | |
306 | ||
da6053d0 LP |
307 | static int append_bind_mounts(MountEntry **p, const BindMount *binds, size_t n) { |
308 | size_t i; | |
d2d6c096 LP |
309 | |
310 | assert(p); | |
311 | ||
312 | for (i = 0; i < n; i++) { | |
313 | const BindMount *b = binds + i; | |
314 | ||
315 | *((*p)++) = (MountEntry) { | |
316 | .path_const = b->destination, | |
317 | .mode = b->recursive ? BIND_MOUNT_RECURSIVE : BIND_MOUNT, | |
318 | .read_only = b->read_only, | |
9ce4e4b0 | 319 | .nosuid = b->nosuid, |
d2d6c096 | 320 | .source_const = b->source, |
4ca763a9 | 321 | .ignore = b->ignore_enoent, |
d2d6c096 LP |
322 | }; |
323 | } | |
324 | ||
325 | return 0; | |
326 | } | |
327 | ||
da6053d0 | 328 | static int append_tmpfs_mounts(MountEntry **p, const TemporaryFileSystem *tmpfs, size_t n) { |
2abd4e38 YW |
329 | assert(p); |
330 | ||
b67ec8e5 | 331 | for (size_t i = 0; i < n; i++) { |
2abd4e38 YW |
332 | const TemporaryFileSystem *t = tmpfs + i; |
333 | _cleanup_free_ char *o = NULL, *str = NULL; | |
ad8e66dc | 334 | unsigned long flags; |
2abd4e38 | 335 | bool ro = false; |
b67ec8e5 | 336 | int r; |
2abd4e38 | 337 | |
baaa35ad ZJS |
338 | if (!path_is_absolute(t->path)) |
339 | return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), | |
340 | "Path is not absolute: %s", | |
341 | t->path); | |
2abd4e38 | 342 | |
b67ec8e5 | 343 | str = strjoin("mode=0755" NESTED_TMPFS_LIMITS ",", t->options); |
ad8e66dc AJ |
344 | if (!str) |
345 | return -ENOMEM; | |
2abd4e38 | 346 | |
ad8e66dc AJ |
347 | r = mount_option_mangle(str, MS_NODEV|MS_STRICTATIME, &flags, &o); |
348 | if (r < 0) | |
349 | return log_debug_errno(r, "Failed to parse mount option '%s': %m", str); | |
2abd4e38 | 350 | |
ad8e66dc AJ |
351 | ro = flags & MS_RDONLY; |
352 | if (ro) | |
353 | flags ^= MS_RDONLY; | |
2abd4e38 YW |
354 | |
355 | *((*p)++) = (MountEntry) { | |
356 | .path_const = t->path, | |
357 | .mode = TMPFS, | |
358 | .read_only = ro, | |
ad8e66dc | 359 | .options_malloc = TAKE_PTR(o), |
2abd4e38 YW |
360 | .flags = flags, |
361 | }; | |
2abd4e38 YW |
362 | } |
363 | ||
364 | return 0; | |
365 | } | |
366 | ||
da6053d0 LP |
367 | static int append_static_mounts(MountEntry **p, const MountEntry *mounts, size_t n, bool ignore_protect) { |
368 | size_t i; | |
11a30cec DH |
369 | |
370 | assert(p); | |
f471b2af | 371 | assert(mounts); |
11a30cec | 372 | |
5327c910 | 373 | /* Adds a list of static pre-defined entries */ |
f471b2af | 374 | |
5327c910 | 375 | for (i = 0; i < n; i++) |
34de407a LP |
376 | *((*p)++) = (MountEntry) { |
377 | .path_const = mount_entry_path(mounts+i), | |
5327c910 LP |
378 | .mode = mounts[i].mode, |
379 | .ignore = mounts[i].ignore || ignore_protect, | |
380 | }; | |
f471b2af DH |
381 | |
382 | return 0; | |
383 | } | |
384 | ||
34de407a | 385 | static int append_protect_home(MountEntry **p, ProtectHome protect_home, bool ignore_protect) { |
c575770b DH |
386 | assert(p); |
387 | ||
5327c910 | 388 | switch (protect_home) { |
b6c432ca | 389 | |
5327c910 | 390 | case PROTECT_HOME_NO: |
b6c432ca DH |
391 | return 0; |
392 | ||
b6c432ca | 393 | case PROTECT_HOME_READ_ONLY: |
5327c910 LP |
394 | return append_static_mounts(p, protect_home_read_only_table, ELEMENTSOF(protect_home_read_only_table), ignore_protect); |
395 | ||
e4da7d8c YW |
396 | case PROTECT_HOME_TMPFS: |
397 | return append_static_mounts(p, protect_home_tmpfs_table, ELEMENTSOF(protect_home_tmpfs_table), ignore_protect); | |
398 | ||
b6c432ca | 399 | case PROTECT_HOME_YES: |
5327c910 LP |
400 | return append_static_mounts(p, protect_home_yes_table, ELEMENTSOF(protect_home_yes_table), ignore_protect); |
401 | ||
b6c432ca | 402 | default: |
5327c910 | 403 | assert_not_reached("Unexpected ProtectHome= value"); |
b6c432ca | 404 | } |
b6c432ca DH |
405 | } |
406 | ||
34de407a | 407 | static int append_protect_system(MountEntry **p, ProtectSystem protect_system, bool ignore_protect) { |
f471b2af DH |
408 | assert(p); |
409 | ||
5327c910 LP |
410 | switch (protect_system) { |
411 | ||
412 | case PROTECT_SYSTEM_NO: | |
f471b2af DH |
413 | return 0; |
414 | ||
f471b2af | 415 | case PROTECT_SYSTEM_STRICT: |
5327c910 LP |
416 | return append_static_mounts(p, protect_system_strict_table, ELEMENTSOF(protect_system_strict_table), ignore_protect); |
417 | ||
f471b2af | 418 | case PROTECT_SYSTEM_YES: |
5327c910 LP |
419 | return append_static_mounts(p, protect_system_yes_table, ELEMENTSOF(protect_system_yes_table), ignore_protect); |
420 | ||
f471b2af | 421 | case PROTECT_SYSTEM_FULL: |
5327c910 LP |
422 | return append_static_mounts(p, protect_system_full_table, ELEMENTSOF(protect_system_full_table), ignore_protect); |
423 | ||
f471b2af | 424 | default: |
5327c910 | 425 | assert_not_reached("Unexpected ProtectSystem= value"); |
f471b2af | 426 | } |
11a30cec DH |
427 | } |
428 | ||
93bab288 | 429 | static int mount_path_compare(const MountEntry *a, const MountEntry *b) { |
a0827e2b | 430 | int d; |
15ae422b | 431 | |
6ee1a919 | 432 | /* If the paths are not equal, then order prefixes first */ |
93bab288 | 433 | d = path_compare(mount_entry_path(a), mount_entry_path(b)); |
6ee1a919 LP |
434 | if (d != 0) |
435 | return d; | |
15ae422b | 436 | |
6ee1a919 | 437 | /* If the paths are equal, check the mode */ |
93bab288 | 438 | return CMP((int) a->mode, (int) b->mode); |
15ae422b LP |
439 | } |
440 | ||
da6053d0 LP |
441 | static int prefix_where_needed(MountEntry *m, size_t n, const char *root_directory) { |
442 | size_t i; | |
5327c910 | 443 | |
4a756839 | 444 | /* Prefixes all paths in the bind mount table with the root directory if the entry needs that. */ |
5327c910 LP |
445 | |
446 | for (i = 0; i < n; i++) { | |
447 | char *s; | |
448 | ||
449 | if (m[i].has_prefix) | |
450 | continue; | |
451 | ||
c6134d3e | 452 | s = path_join(root_directory, mount_entry_path(m+i)); |
5327c910 LP |
453 | if (!s) |
454 | return -ENOMEM; | |
455 | ||
e282f51f | 456 | free_and_replace(m[i].path_malloc, s); |
5327c910 LP |
457 | m[i].has_prefix = true; |
458 | } | |
459 | ||
460 | return 0; | |
461 | } | |
462 | ||
da6053d0 | 463 | static void drop_duplicates(MountEntry *m, size_t *n) { |
34de407a | 464 | MountEntry *f, *t, *previous; |
15ae422b | 465 | |
c17ec25e | 466 | assert(m); |
15ae422b | 467 | assert(n); |
15ae422b | 468 | |
fe3c2583 LP |
469 | /* Drops duplicate entries. Expects that the array is properly ordered already. */ |
470 | ||
1d54cd5d | 471 | for (f = m, t = m, previous = NULL; f < m + *n; f++) { |
15ae422b | 472 | |
fe3c2583 | 473 | /* The first one wins (which is the one with the more restrictive mode), see mount_path_compare() |
088696fe LP |
474 | * above. Note that we only drop duplicates that haven't been mounted yet. */ |
475 | if (previous && | |
476 | path_equal(mount_entry_path(f), mount_entry_path(previous)) && | |
477 | !f->applied && !previous->applied) { | |
5beb8688 | 478 | log_debug("%s (%s) is duplicate.", mount_entry_path(f), mount_mode_to_string(f->mode)); |
34de407a | 479 | previous->read_only = previous->read_only || mount_entry_read_only(f); /* Propagate the read-only flag to the remaining entry */ |
1eb7e08e | 480 | mount_entry_done(f); |
15ae422b | 481 | continue; |
fe3c2583 | 482 | } |
15ae422b | 483 | |
e2d7c1a0 | 484 | *t = *f; |
15ae422b | 485 | previous = t; |
fe3c2583 LP |
486 | t++; |
487 | } | |
488 | ||
489 | *n = t - m; | |
490 | } | |
491 | ||
da6053d0 | 492 | static void drop_inaccessible(MountEntry *m, size_t *n) { |
34de407a | 493 | MountEntry *f, *t; |
fe3c2583 LP |
494 | const char *clear = NULL; |
495 | ||
496 | assert(m); | |
497 | assert(n); | |
498 | ||
499 | /* Drops all entries obstructed by another entry further up the tree. Expects that the array is properly | |
500 | * ordered already. */ | |
501 | ||
1d54cd5d | 502 | for (f = m, t = m; f < m + *n; f++) { |
fe3c2583 LP |
503 | |
504 | /* If we found a path set for INACCESSIBLE earlier, and this entry has it as prefix we should drop | |
505 | * it, as inaccessible paths really should drop the entire subtree. */ | |
34de407a LP |
506 | if (clear && path_startswith(mount_entry_path(f), clear)) { |
507 | log_debug("%s is masked by %s.", mount_entry_path(f), clear); | |
1eb7e08e | 508 | mount_entry_done(f); |
fe3c2583 LP |
509 | continue; |
510 | } | |
15ae422b | 511 | |
34de407a | 512 | clear = f->mode == INACCESSIBLE ? mount_entry_path(f) : NULL; |
fe3c2583 LP |
513 | |
514 | *t = *f; | |
15ae422b LP |
515 | t++; |
516 | } | |
517 | ||
c17ec25e | 518 | *n = t - m; |
15ae422b LP |
519 | } |
520 | ||
da6053d0 | 521 | static void drop_nop(MountEntry *m, size_t *n) { |
34de407a | 522 | MountEntry *f, *t; |
7648a565 LP |
523 | |
524 | assert(m); | |
525 | assert(n); | |
526 | ||
527 | /* Drops all entries which have an immediate parent that has the same type, as they are redundant. Assumes the | |
528 | * list is ordered by prefixes. */ | |
529 | ||
1d54cd5d | 530 | for (f = m, t = m; f < m + *n; f++) { |
7648a565 | 531 | |
1e05071d YW |
532 | /* Only suppress such subtrees for READONLY, READWRITE and READWRITE_IMPLICIT entries */ |
533 | if (IN_SET(f->mode, READONLY, READWRITE, READWRITE_IMPLICIT)) { | |
34de407a | 534 | MountEntry *p; |
7648a565 LP |
535 | bool found = false; |
536 | ||
537 | /* Now let's find the first parent of the entry we are looking at. */ | |
538 | for (p = t-1; p >= m; p--) { | |
34de407a | 539 | if (path_startswith(mount_entry_path(f), mount_entry_path(p))) { |
7648a565 LP |
540 | found = true; |
541 | break; | |
542 | } | |
543 | } | |
544 | ||
545 | /* We found it, let's see if it's the same mode, if so, we can drop this entry */ | |
546 | if (found && p->mode == f->mode) { | |
5beb8688 YW |
547 | log_debug("%s (%s) is made redundant by %s (%s)", |
548 | mount_entry_path(f), mount_mode_to_string(f->mode), | |
549 | mount_entry_path(p), mount_mode_to_string(p->mode)); | |
1eb7e08e | 550 | mount_entry_done(f); |
7648a565 LP |
551 | continue; |
552 | } | |
553 | } | |
554 | ||
555 | *t = *f; | |
556 | t++; | |
557 | } | |
558 | ||
559 | *n = t - m; | |
560 | } | |
561 | ||
da6053d0 | 562 | static void drop_outside_root(const char *root_directory, MountEntry *m, size_t *n) { |
34de407a | 563 | MountEntry *f, *t; |
cd2902c9 LP |
564 | |
565 | assert(m); | |
566 | assert(n); | |
567 | ||
1d54cd5d | 568 | /* Nothing to do */ |
cd2902c9 LP |
569 | if (!root_directory) |
570 | return; | |
571 | ||
572 | /* Drops all mounts that are outside of the root directory. */ | |
573 | ||
1d54cd5d | 574 | for (f = m, t = m; f < m + *n; f++) { |
cd2902c9 | 575 | |
34de407a LP |
576 | if (!path_startswith(mount_entry_path(f), root_directory)) { |
577 | log_debug("%s is outside of root directory.", mount_entry_path(f)); | |
1eb7e08e | 578 | mount_entry_done(f); |
cd2902c9 LP |
579 | continue; |
580 | } | |
581 | ||
582 | *t = *f; | |
583 | t++; | |
584 | } | |
585 | ||
586 | *n = t - m; | |
587 | } | |
588 | ||
b2a60844 LP |
589 | static int clone_device_node( |
590 | const char *d, | |
591 | const char *temporary_mount, | |
592 | bool *make_devnode) { | |
593 | ||
594 | _cleanup_free_ char *sl = NULL; | |
595 | const char *dn, *bn, *t; | |
b5e99f23 ДГ |
596 | struct stat st; |
597 | int r; | |
598 | ||
414b304b | 599 | if (stat(d, &st) < 0) { |
b2a60844 LP |
600 | if (errno == ENOENT) { |
601 | log_debug_errno(errno, "Device node '%s' to clone does not exist, ignoring.", d); | |
af984e13 | 602 | return -ENXIO; |
b2a60844 LP |
603 | } |
604 | ||
605 | return log_debug_errno(errno, "Failed to stat() device node '%s' to clone, ignoring: %m", d); | |
b5e99f23 ДГ |
606 | } |
607 | ||
608 | if (!S_ISBLK(st.st_mode) && | |
baaa35ad ZJS |
609 | !S_ISCHR(st.st_mode)) |
610 | return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), | |
611 | "Device node '%s' to clone is not a device node, ignoring.", | |
612 | d); | |
b5e99f23 | 613 | |
6f7f3a33 | 614 | dn = strjoina(temporary_mount, d); |
b5e99f23 | 615 | |
b2a60844 | 616 | /* First, try to create device node properly */ |
16498617 CB |
617 | if (*make_devnode) { |
618 | mac_selinux_create_file_prepare(d, st.st_mode); | |
619 | r = mknod(dn, st.st_mode, st.st_rdev); | |
620 | mac_selinux_create_file_clear(); | |
b2a60844 LP |
621 | if (r >= 0) |
622 | goto add_symlink; | |
16498617 CB |
623 | if (errno != EPERM) |
624 | return log_debug_errno(errno, "mknod failed for %s: %m", d); | |
625 | ||
b2a60844 | 626 | /* This didn't work, let's not try this again for the next iterations. */ |
16498617 CB |
627 | *make_devnode = false; |
628 | } | |
629 | ||
630 | /* We're about to fallback to bind-mounting the device | |
1acf344d CG |
631 | * node. So create a dummy bind-mount target. |
632 | * Do not prepare device-node SELinux label (see issue 13762) */ | |
16498617 | 633 | r = mknod(dn, S_IFREG, 0); |
16498617 | 634 | if (r < 0 && errno != EEXIST) |
b2a60844 | 635 | return log_debug_errno(errno, "mknod() fallback failed for '%s': %m", d); |
16498617 CB |
636 | |
637 | /* Fallback to bind-mounting: | |
638 | * The assumption here is that all used device nodes carry standard | |
639 | * properties. Specifically, the devices nodes we bind-mount should | |
640 | * either be owned by root:root or root:tty (e.g. /dev/tty, /dev/ptmx) | |
641 | * and should not carry ACLs. */ | |
642 | if (mount(d, dn, NULL, MS_BIND, NULL) < 0) | |
b2a60844 LP |
643 | return log_debug_errno(errno, "Bind mounting failed for '%s': %m", d); |
644 | ||
645 | add_symlink: | |
646 | bn = path_startswith(d, "/dev/"); | |
647 | if (!bn) | |
648 | return 0; | |
649 | ||
650 | /* Create symlinks like /dev/char/1:9 → ../urandom */ | |
cbc056c8 ZJS |
651 | if (asprintf(&sl, "%s/dev/%s/%u:%u", |
652 | temporary_mount, | |
653 | S_ISCHR(st.st_mode) ? "char" : "block", | |
654 | major(st.st_rdev), minor(st.st_rdev)) < 0) | |
b2a60844 LP |
655 | return log_oom(); |
656 | ||
657 | (void) mkdir_parents(sl, 0755); | |
658 | ||
659 | t = strjoina("../", bn); | |
b2a60844 | 660 | if (symlink(t, sl) < 0) |
2e4a4fae | 661 | log_debug_errno(errno, "Failed to symlink '%s' to '%s', ignoring: %m", t, sl); |
b5e99f23 | 662 | |
af984e13 | 663 | return 0; |
b5e99f23 ДГ |
664 | } |
665 | ||
5d997827 | 666 | static int mount_private_dev(MountEntry *m) { |
7f112f50 LP |
667 | static const char devnodes[] = |
668 | "/dev/null\0" | |
669 | "/dev/zero\0" | |
670 | "/dev/full\0" | |
671 | "/dev/random\0" | |
672 | "/dev/urandom\0" | |
673 | "/dev/tty\0"; | |
674 | ||
2b85f4e1 | 675 | char temporary_mount[] = "/tmp/namespace-dev-XXXXXX"; |
63cc4c31 | 676 | const char *d, *dev = NULL, *devpts = NULL, *devshm = NULL, *devhugepages = NULL, *devmqueue = NULL, *devlog = NULL, *devptmx = NULL; |
16498617 | 677 | bool can_mknod = true; |
7f112f50 LP |
678 | _cleanup_umask_ mode_t u; |
679 | int r; | |
680 | ||
681 | assert(m); | |
682 | ||
683 | u = umask(0000); | |
684 | ||
2b85f4e1 | 685 | if (!mkdtemp(temporary_mount)) |
2e4a4fae | 686 | return log_debug_errno(errno, "Failed to create temporary directory '%s': %m", temporary_mount); |
2b85f4e1 | 687 | |
63c372cb | 688 | dev = strjoina(temporary_mount, "/dev"); |
dc751688 | 689 | (void) mkdir(dev, 0755); |
7d85383e | 690 | if (mount("tmpfs", dev, "tmpfs", DEV_MOUNT_OPTIONS, "mode=755" TMPFS_LIMITS_DEV) < 0) { |
2e4a4fae | 691 | r = log_debug_errno(errno, "Failed to mount tmpfs on '%s': %m", dev); |
2b85f4e1 LP |
692 | goto fail; |
693 | } | |
c3151977 TM |
694 | r = label_fix_container(dev, "/dev", 0); |
695 | if (r < 0) { | |
696 | log_debug_errno(errno, "Failed to fix label of '%s' as /dev: %m", dev); | |
697 | goto fail; | |
698 | } | |
2b85f4e1 | 699 | |
63c372cb | 700 | devpts = strjoina(temporary_mount, "/dev/pts"); |
dc751688 | 701 | (void) mkdir(devpts, 0755); |
2b85f4e1 | 702 | if (mount("/dev/pts", devpts, NULL, MS_BIND, NULL) < 0) { |
2e4a4fae | 703 | r = log_debug_errno(errno, "Failed to bind mount /dev/pts on '%s': %m", devpts); |
2b85f4e1 LP |
704 | goto fail; |
705 | } | |
706 | ||
2e4a4fae YW |
707 | /* /dev/ptmx can either be a device node or a symlink to /dev/pts/ptmx. |
708 | * When /dev/ptmx a device node, /dev/pts/ptmx has 000 permissions making it inaccessible. | |
709 | * Thus, in that case make a clone. | |
710 | * In nspawn and other containers it will be a symlink, in that case make it a symlink. */ | |
36ce7110 | 711 | r = is_symlink("/dev/ptmx"); |
2e4a4fae YW |
712 | if (r < 0) { |
713 | log_debug_errno(r, "Failed to detect whether /dev/ptmx is a symlink or not: %m"); | |
3164e3cb | 714 | goto fail; |
2e4a4fae | 715 | } else if (r > 0) { |
414b304b ДГ |
716 | devptmx = strjoina(temporary_mount, "/dev/ptmx"); |
717 | if (symlink("pts/ptmx", devptmx) < 0) { | |
2e4a4fae | 718 | r = log_debug_errno(errno, "Failed to create a symlink '%s' to pts/ptmx: %m", devptmx); |
414b304b ДГ |
719 | goto fail; |
720 | } | |
721 | } else { | |
16498617 | 722 | r = clone_device_node("/dev/ptmx", temporary_mount, &can_mknod); |
152c475f LP |
723 | if (r < 0) |
724 | goto fail; | |
414b304b | 725 | } |
e06b6479 | 726 | |
63c372cb | 727 | devshm = strjoina(temporary_mount, "/dev/shm"); |
8d953682 | 728 | (void) mkdir(devshm, 0755); |
2b85f4e1 LP |
729 | r = mount("/dev/shm", devshm, NULL, MS_BIND, NULL); |
730 | if (r < 0) { | |
2e4a4fae | 731 | r = log_debug_errno(errno, "Failed to bind mount /dev/shm on '%s': %m", devshm); |
2b85f4e1 LP |
732 | goto fail; |
733 | } | |
734 | ||
63c372cb | 735 | devmqueue = strjoina(temporary_mount, "/dev/mqueue"); |
dc751688 | 736 | (void) mkdir(devmqueue, 0755); |
2e4a4fae YW |
737 | if (mount("/dev/mqueue", devmqueue, NULL, MS_BIND, NULL) < 0) |
738 | log_debug_errno(errno, "Failed to bind mount /dev/mqueue on '%s', ignoring: %m", devmqueue); | |
2b85f4e1 | 739 | |
63c372cb | 740 | devhugepages = strjoina(temporary_mount, "/dev/hugepages"); |
dc751688 | 741 | (void) mkdir(devhugepages, 0755); |
2e4a4fae YW |
742 | if (mount("/dev/hugepages", devhugepages, NULL, MS_BIND, NULL) < 0) |
743 | log_debug_errno(errno, "Failed to bind mount /dev/hugepages on '%s', ignoring: %m", devhugepages); | |
2b85f4e1 | 744 | |
63c372cb | 745 | devlog = strjoina(temporary_mount, "/dev/log"); |
2e4a4fae YW |
746 | if (symlink("/run/systemd/journal/dev-log", devlog) < 0) |
747 | log_debug_errno(errno, "Failed to create a symlink '%s' to /run/systemd/journal/dev-log, ignoring: %m", devlog); | |
82d25240 | 748 | |
7f112f50 | 749 | NULSTR_FOREACH(d, devnodes) { |
16498617 | 750 | r = clone_device_node(d, temporary_mount, &can_mknod); |
37b22b3b | 751 | /* ENXIO means the *source* is not a device file, skip creation in that case */ |
af984e13 | 752 | if (r < 0 && r != -ENXIO) |
2b85f4e1 | 753 | goto fail; |
7f112f50 LP |
754 | } |
755 | ||
2e4a4fae YW |
756 | r = dev_setup(temporary_mount, UID_INVALID, GID_INVALID); |
757 | if (r < 0) | |
105a1a36 | 758 | log_debug_errno(r, "Failed to set up basic device tree at '%s', ignoring: %m", temporary_mount); |
7f112f50 | 759 | |
ee818b89 AC |
760 | /* Create the /dev directory if missing. It is more likely to be |
761 | * missing when the service is started with RootDirectory. This is | |
762 | * consistent with mount units creating the mount points when missing. | |
763 | */ | |
34de407a | 764 | (void) mkdir_p_label(mount_entry_path(m), 0755); |
ee818b89 | 765 | |
9e5f8252 | 766 | /* Unmount everything in old /dev */ |
2e4a4fae YW |
767 | r = umount_recursive(mount_entry_path(m), 0); |
768 | if (r < 0) | |
769 | log_debug_errno(r, "Failed to unmount directories below '%s', ignoring: %m", mount_entry_path(m)); | |
770 | ||
34de407a | 771 | if (mount(dev, mount_entry_path(m), NULL, MS_MOVE, NULL) < 0) { |
2e4a4fae | 772 | r = log_debug_errno(errno, "Failed to move mount point '%s' to '%s': %m", dev, mount_entry_path(m)); |
2b85f4e1 LP |
773 | goto fail; |
774 | } | |
7f112f50 | 775 | |
1019a48f LP |
776 | (void) rmdir(dev); |
777 | (void) rmdir(temporary_mount); | |
7f112f50 | 778 | |
2b85f4e1 | 779 | return 0; |
7f112f50 | 780 | |
2b85f4e1 LP |
781 | fail: |
782 | if (devpts) | |
1019a48f | 783 | (void) umount(devpts); |
7f112f50 | 784 | |
2b85f4e1 | 785 | if (devshm) |
1019a48f | 786 | (void) umount(devshm); |
7f112f50 | 787 | |
2b85f4e1 | 788 | if (devhugepages) |
1019a48f | 789 | (void) umount(devhugepages); |
7f112f50 | 790 | |
2b85f4e1 | 791 | if (devmqueue) |
1019a48f | 792 | (void) umount(devmqueue); |
7f112f50 | 793 | |
1019a48f LP |
794 | (void) umount(dev); |
795 | (void) rmdir(dev); | |
796 | (void) rmdir(temporary_mount); | |
7f112f50 | 797 | |
2b85f4e1 | 798 | return r; |
7f112f50 LP |
799 | } |
800 | ||
2a2969fd | 801 | static int mount_bind_dev(const MountEntry *m) { |
5d997827 LP |
802 | int r; |
803 | ||
804 | assert(m); | |
805 | ||
806 | /* Implements the little brother of mount_private_dev(): simply bind mounts the host's /dev into the service's | |
807 | * /dev. This is only used when RootDirectory= is set. */ | |
808 | ||
645767d6 LP |
809 | (void) mkdir_p_label(mount_entry_path(m), 0755); |
810 | ||
5d997827 LP |
811 | r = path_is_mount_point(mount_entry_path(m), NULL, 0); |
812 | if (r < 0) | |
813 | return log_debug_errno(r, "Unable to determine whether /dev is already mounted: %m"); | |
814 | if (r > 0) /* make this a NOP if /dev is already a mount point */ | |
815 | return 0; | |
816 | ||
817 | if (mount("/dev", mount_entry_path(m), NULL, MS_BIND|MS_REC, NULL) < 0) | |
818 | return log_debug_errno(errno, "Failed to bind mount %s: %m", mount_entry_path(m)); | |
819 | ||
820 | return 1; | |
821 | } | |
822 | ||
2a2969fd | 823 | static int mount_sysfs(const MountEntry *m) { |
5d997827 LP |
824 | int r; |
825 | ||
826 | assert(m); | |
827 | ||
645767d6 LP |
828 | (void) mkdir_p_label(mount_entry_path(m), 0755); |
829 | ||
5d997827 LP |
830 | r = path_is_mount_point(mount_entry_path(m), NULL, 0); |
831 | if (r < 0) | |
832 | return log_debug_errno(r, "Unable to determine whether /sys is already mounted: %m"); | |
833 | if (r > 0) /* make this a NOP if /sys is already a mount point */ | |
834 | return 0; | |
835 | ||
836 | /* Bind mount the host's version so that we get all child mounts of it, too. */ | |
837 | if (mount("/sys", mount_entry_path(m), NULL, MS_BIND|MS_REC, NULL) < 0) | |
838 | return log_debug_errno(errno, "Failed to mount %s: %m", mount_entry_path(m)); | |
839 | ||
840 | return 1; | |
841 | } | |
842 | ||
2a2969fd | 843 | static int mount_procfs(const MountEntry *m) { |
5d997827 LP |
844 | int r; |
845 | ||
846 | assert(m); | |
847 | ||
645767d6 LP |
848 | (void) mkdir_p_label(mount_entry_path(m), 0755); |
849 | ||
5d997827 LP |
850 | r = path_is_mount_point(mount_entry_path(m), NULL, 0); |
851 | if (r < 0) | |
852 | return log_debug_errno(r, "Unable to determine whether /proc is already mounted: %m"); | |
853 | if (r > 0) /* make this a NOP if /proc is already a mount point */ | |
854 | return 0; | |
855 | ||
856 | /* Mount a new instance, so that we get the one that matches our user namespace, if we are running in one */ | |
857 | if (mount("proc", mount_entry_path(m), "proc", MS_NOSUID|MS_NOEXEC|MS_NODEV, NULL) < 0) | |
858 | return log_debug_errno(errno, "Failed to mount %s: %m", mount_entry_path(m)); | |
859 | ||
860 | return 1; | |
861 | } | |
862 | ||
2abd4e38 | 863 | static int mount_tmpfs(const MountEntry *m) { |
abad72be CG |
864 | int r; |
865 | const char *entry_path = mount_entry_path(m); | |
866 | const char *source_path = m->path_const; | |
867 | ||
6c47cd7d LP |
868 | assert(m); |
869 | ||
2abd4e38 | 870 | /* First, get rid of everything that is below if there is anything. Then, overmount with our new tmpfs */ |
6c47cd7d | 871 | |
abad72be CG |
872 | (void) mkdir_p_label(entry_path, 0755); |
873 | (void) umount_recursive(entry_path, 0); | |
6c47cd7d | 874 | |
abad72be CG |
875 | if (mount("tmpfs", entry_path, "tmpfs", m->flags, mount_entry_options(m)) < 0) |
876 | return log_debug_errno(errno, "Failed to mount %s: %m", entry_path); | |
877 | ||
878 | r = label_fix_container(entry_path, source_path, 0); | |
879 | if (r < 0) | |
f2df56bf | 880 | return log_debug_errno(r, "Failed to fix label of '%s' as '%s': %m", entry_path, source_path); |
6c47cd7d LP |
881 | |
882 | return 1; | |
883 | } | |
884 | ||
088696fe | 885 | static int follow_symlink( |
d2d6c096 | 886 | const char *root_directory, |
088696fe | 887 | MountEntry *m) { |
d2d6c096 | 888 | |
088696fe | 889 | _cleanup_free_ char *target = NULL; |
8fceda93 LP |
890 | int r; |
891 | ||
088696fe LP |
892 | /* Let's chase symlinks, but only one step at a time. That's because depending where the symlink points we |
893 | * might need to change the order in which we mount stuff. Hence: let's normalize piecemeal, and do one step at | |
894 | * a time by specifying CHASE_STEP. This function returns 0 if we resolved one step, and > 0 if we reached the | |
895 | * end and already have a fully normalized name. */ | |
8fceda93 | 896 | |
a5648b80 | 897 | r = chase_symlinks(mount_entry_path(m), root_directory, CHASE_STEP|CHASE_NONEXISTENT, &target, NULL); |
088696fe LP |
898 | if (r < 0) |
899 | return log_debug_errno(r, "Failed to chase symlinks '%s': %m", mount_entry_path(m)); | |
900 | if (r > 0) /* Reached the end, nothing more to resolve */ | |
901 | return 1; | |
8fceda93 | 902 | |
baaa35ad ZJS |
903 | if (m->n_followed >= CHASE_SYMLINKS_MAX) /* put a boundary on things */ |
904 | return log_debug_errno(SYNTHETIC_ERRNO(ELOOP), | |
905 | "Symlink loop on '%s'.", | |
906 | mount_entry_path(m)); | |
8fceda93 | 907 | |
088696fe | 908 | log_debug("Followed mount entry path symlink %s → %s.", mount_entry_path(m), target); |
8fceda93 | 909 | |
088696fe LP |
910 | free_and_replace(m->path_malloc, target); |
911 | m->has_prefix = true; | |
8fceda93 | 912 | |
088696fe LP |
913 | m->n_followed ++; |
914 | ||
915 | return 0; | |
8fceda93 LP |
916 | } |
917 | ||
ac0930c8 | 918 | static int apply_mount( |
8fceda93 | 919 | const char *root_directory, |
89bd586c | 920 | MountEntry *m) { |
ac0930c8 | 921 | |
e5f10caf | 922 | _cleanup_free_ char *inaccessible = NULL; |
a227a4be | 923 | bool rbind = true, make = false; |
15ae422b | 924 | const char *what; |
15ae422b | 925 | int r; |
15ae422b | 926 | |
c17ec25e | 927 | assert(m); |
15ae422b | 928 | |
34de407a | 929 | log_debug("Applying namespace mount on %s", mount_entry_path(m)); |
fe3c2583 | 930 | |
c17ec25e | 931 | switch (m->mode) { |
15ae422b | 932 | |
160cfdbe | 933 | case INACCESSIBLE: { |
e5f10caf AZ |
934 | _cleanup_free_ char *tmp = NULL; |
935 | const char *runtime_dir; | |
160cfdbe | 936 | struct stat target; |
6d313367 LP |
937 | |
938 | /* First, get rid of everything that is below if there | |
939 | * is anything... Then, overmount it with an | |
c4b41707 | 940 | * inaccessible path. */ |
34de407a | 941 | (void) umount_recursive(mount_entry_path(m), 0); |
6d313367 | 942 | |
088696fe LP |
943 | if (lstat(mount_entry_path(m), &target) < 0) { |
944 | if (errno == ENOENT && m->ignore) | |
945 | return 0; | |
946 | ||
cbc056c8 ZJS |
947 | return log_debug_errno(errno, "Failed to lstat() %s to determine what to mount over it: %m", |
948 | mount_entry_path(m)); | |
088696fe | 949 | } |
15ae422b | 950 | |
e5f10caf | 951 | if (geteuid() == 0) |
48b747fa | 952 | runtime_dir = "/run"; |
e5f10caf | 953 | else { |
48b747fa LP |
954 | if (asprintf(&tmp, "/run/user/" UID_FMT, geteuid()) < 0) |
955 | return -ENOMEM; | |
e5f10caf AZ |
956 | |
957 | runtime_dir = tmp; | |
958 | } | |
959 | ||
960 | r = mode_to_inaccessible_node(runtime_dir, target.st_mode, &inaccessible); | |
961 | if (r < 0) | |
baaa35ad ZJS |
962 | return log_debug_errno(SYNTHETIC_ERRNO(ELOOP), |
963 | "File type not supported for inaccessible mounts. Note that symlinks are not allowed"); | |
e5f10caf | 964 | what = inaccessible; |
c4b41707 | 965 | break; |
160cfdbe | 966 | } |
fe3c2583 | 967 | |
15ae422b | 968 | case READONLY: |
15ae422b | 969 | case READWRITE: |
1e05071d | 970 | case READWRITE_IMPLICIT: |
8fceda93 | 971 | r = path_is_mount_point(mount_entry_path(m), root_directory, 0); |
088696fe LP |
972 | if (r == -ENOENT && m->ignore) |
973 | return 0; | |
d944dc95 | 974 | if (r < 0) |
cbc056c8 ZJS |
975 | return log_debug_errno(r, "Failed to determine whether %s is already a mount point: %m", |
976 | mount_entry_path(m)); | |
977 | if (r > 0) /* Nothing to do here, it is already a mount. We just later toggle the MS_RDONLY | |
978 | * bit for the mount point if needed. */ | |
6b7c9f8b | 979 | return 0; |
6b7c9f8b | 980 | /* This isn't a mount point yet, let's make it one. */ |
34de407a | 981 | what = mount_entry_path(m); |
6b7c9f8b | 982 | break; |
15ae422b | 983 | |
d2d6c096 LP |
984 | case BIND_MOUNT: |
985 | rbind = false; | |
d2d6c096 | 986 | |
4831981d | 987 | _fallthrough_; |
088696fe LP |
988 | case BIND_MOUNT_RECURSIVE: { |
989 | _cleanup_free_ char *chased = NULL; | |
5d997827 | 990 | |
cbc056c8 ZJS |
991 | /* Since mount() will always follow symlinks we chase the symlinks on our own first. Note |
992 | * that bind mount source paths are always relative to the host root, hence we pass NULL as | |
993 | * root directory to chase_symlinks() here. */ | |
088696fe | 994 | |
a5648b80 | 995 | r = chase_symlinks(mount_entry_source(m), NULL, CHASE_TRAIL_SLASH, &chased, NULL); |
088696fe LP |
996 | if (r == -ENOENT && m->ignore) { |
997 | log_debug_errno(r, "Path %s does not exist, ignoring.", mount_entry_source(m)); | |
998 | return 0; | |
999 | } | |
1000 | if (r < 0) | |
1001 | return log_debug_errno(r, "Failed to follow symlinks on %s: %m", mount_entry_source(m)); | |
1002 | ||
1003 | log_debug("Followed source symlinks %s → %s.", mount_entry_source(m), chased); | |
1004 | ||
1005 | free_and_replace(m->source_malloc, chased); | |
d2d6c096 LP |
1006 | |
1007 | what = mount_entry_source(m); | |
a227a4be | 1008 | make = true; |
d2d6c096 | 1009 | break; |
088696fe | 1010 | } |
d2d6c096 | 1011 | |
6c47cd7d | 1012 | case EMPTY_DIR: |
2abd4e38 YW |
1013 | case TMPFS: |
1014 | return mount_tmpfs(m); | |
6c47cd7d | 1015 | |
ac0930c8 | 1016 | case PRIVATE_TMP: |
56a13a49 | 1017 | case PRIVATE_TMP_READONLY: |
89bd586c | 1018 | what = mount_entry_source(m); |
a227a4be | 1019 | make = true; |
15ae422b | 1020 | break; |
e364ad06 | 1021 | |
d6797c92 | 1022 | case PRIVATE_DEV: |
5d997827 LP |
1023 | return mount_private_dev(m); |
1024 | ||
1025 | case BIND_DEV: | |
1026 | return mount_bind_dev(m); | |
1027 | ||
1028 | case SYSFS: | |
1029 | return mount_sysfs(m); | |
1030 | ||
1031 | case PROCFS: | |
1032 | return mount_procfs(m); | |
d6797c92 | 1033 | |
e364ad06 LP |
1034 | default: |
1035 | assert_not_reached("Unknown mode"); | |
15ae422b LP |
1036 | } |
1037 | ||
ac0930c8 | 1038 | assert(what); |
15ae422b | 1039 | |
a227a4be LP |
1040 | if (mount(what, mount_entry_path(m), NULL, MS_BIND|(rbind ? MS_REC : 0), NULL) < 0) { |
1041 | bool try_again = false; | |
1042 | r = -errno; | |
1043 | ||
1044 | if (r == -ENOENT && make) { | |
1045 | struct stat st; | |
1046 | ||
cbc056c8 ZJS |
1047 | /* Hmm, either the source or the destination are missing. Let's see if we can create |
1048 | the destination, then try again. */ | |
a227a4be | 1049 | |
e8717862 | 1050 | if (stat(what, &st) < 0) |
5dc60faa | 1051 | log_error_errno(errno, "Mount point source '%s' is not accessible: %m", what); |
e8717862 LP |
1052 | else { |
1053 | int q; | |
a227a4be LP |
1054 | |
1055 | (void) mkdir_parents(mount_entry_path(m), 0755); | |
1056 | ||
1057 | if (S_ISDIR(st.st_mode)) | |
e8717862 | 1058 | q = mkdir(mount_entry_path(m), 0755) < 0 ? -errno : 0; |
a227a4be | 1059 | else |
e8717862 LP |
1060 | q = touch(mount_entry_path(m)); |
1061 | ||
1062 | if (q < 0) | |
cbc056c8 ZJS |
1063 | log_error_errno(q, "Failed to create destination mount point node '%s': %m", |
1064 | mount_entry_path(m)); | |
e8717862 LP |
1065 | else |
1066 | try_again = true; | |
a227a4be LP |
1067 | } |
1068 | } | |
1069 | ||
1070 | if (try_again) { | |
1071 | if (mount(what, mount_entry_path(m), NULL, MS_BIND|(rbind ? MS_REC : 0), NULL) < 0) | |
1072 | r = -errno; | |
1073 | else | |
1074 | r = 0; | |
1075 | } | |
1076 | ||
1077 | if (r < 0) | |
5dc60faa | 1078 | return log_error_errno(r, "Failed to mount %s to %s: %m", what, mount_entry_path(m)); |
a227a4be | 1079 | } |
6b7c9f8b | 1080 | |
34de407a | 1081 | log_debug("Successfully mounted %s to %s", what, mount_entry_path(m)); |
6b7c9f8b | 1082 | return 0; |
ac0930c8 | 1083 | } |
15ae422b | 1084 | |
6b000af4 | 1085 | static int make_read_only(const MountEntry *m, char **deny_list, FILE *proc_self_mountinfo) { |
9ce4e4b0 | 1086 | unsigned long new_flags = 0, flags_mask = 0; |
763a260a | 1087 | bool submounts = false; |
6b7c9f8b | 1088 | int r = 0; |
15ae422b | 1089 | |
c17ec25e | 1090 | assert(m); |
ac9de0b3 | 1091 | assert(proc_self_mountinfo); |
ac0930c8 | 1092 | |
9ce4e4b0 LP |
1093 | if (mount_entry_read_only(m) || m->mode == PRIVATE_DEV) { |
1094 | new_flags |= MS_RDONLY; | |
1095 | flags_mask |= MS_RDONLY; | |
1096 | } | |
1097 | ||
1098 | if (m->nosuid) { | |
1099 | new_flags |= MS_NOSUID; | |
1100 | flags_mask |= MS_NOSUID; | |
1101 | } | |
1102 | ||
1103 | if (flags_mask == 0) /* No Change? */ | |
6b7c9f8b LP |
1104 | return 0; |
1105 | ||
9ce4e4b0 LP |
1106 | /* We generally apply these changes recursively, except for /dev, and the cases we know there's |
1107 | * nothing further down. Set /dev readonly, but not submounts like /dev/shm. Also, we only set the | |
1108 | * per-mount read-only flag. We can't set it on the superblock, if we are inside a user namespace | |
1109 | * and running Linux <= 4.17. */ | |
1110 | submounts = | |
1111 | mount_entry_read_only(m) && | |
1112 | !IN_SET(m->mode, EMPTY_DIR, TMPFS); | |
1113 | if (submounts) | |
6b000af4 | 1114 | r = bind_remount_recursive_with_mountinfo(mount_entry_path(m), new_flags, flags_mask, deny_list, proc_self_mountinfo); |
9ce4e4b0 | 1115 | else |
7cce68e1 | 1116 | r = bind_remount_one_with_mountinfo(mount_entry_path(m), new_flags, flags_mask, proc_self_mountinfo); |
9ce4e4b0 | 1117 | |
867189b5 LP |
1118 | /* Not that we only turn on the MS_RDONLY flag here, we never turn it off. Something that was marked |
1119 | * read-only already stays this way. This improves compatibility with container managers, where we | |
1120 | * won't attempt to undo read-only mounts already applied. */ | |
ac0930c8 | 1121 | |
8fceda93 | 1122 | if (r == -ENOENT && m->ignore) |
867189b5 | 1123 | return 0; |
763a260a | 1124 | if (r < 0) |
9ce4e4b0 | 1125 | return log_debug_errno(r, "Failed to re-mount '%s'%s: %m", mount_entry_path(m), |
763a260a | 1126 | submounts ? " and its submounts" : ""); |
763a260a | 1127 | return 0; |
d944dc95 LP |
1128 | } |
1129 | ||
9b68367b | 1130 | static bool namespace_info_mount_apivfs(const NamespaceInfo *ns_info) { |
5d997827 LP |
1131 | assert(ns_info); |
1132 | ||
9c988f93 DH |
1133 | /* |
1134 | * ProtectControlGroups= and ProtectKernelTunables= imply MountAPIVFS=, | |
1135 | * since to protect the API VFS mounts, they need to be around in the | |
9b68367b | 1136 | * first place... |
9c988f93 | 1137 | */ |
5d997827 | 1138 | |
9b68367b YW |
1139 | return ns_info->mount_apivfs || |
1140 | ns_info->protect_control_groups || | |
1141 | ns_info->protect_kernel_tunables; | |
5d997827 LP |
1142 | } |
1143 | ||
da6053d0 | 1144 | static size_t namespace_calculate_mounts( |
bb0ff3fb | 1145 | const NamespaceInfo *ns_info, |
2652c6c1 DH |
1146 | char** read_write_paths, |
1147 | char** read_only_paths, | |
1148 | char** inaccessible_paths, | |
6c47cd7d | 1149 | char** empty_directories, |
da6053d0 LP |
1150 | size_t n_bind_mounts, |
1151 | size_t n_temporary_filesystems, | |
2652c6c1 DH |
1152 | const char* tmp_dir, |
1153 | const char* var_tmp_dir, | |
91dd5f7c | 1154 | const char* log_namespace, |
2652c6c1 DH |
1155 | ProtectHome protect_home, |
1156 | ProtectSystem protect_system) { | |
1157 | ||
da6053d0 LP |
1158 | size_t protect_home_cnt; |
1159 | size_t protect_system_cnt = | |
f471b2af DH |
1160 | (protect_system == PROTECT_SYSTEM_STRICT ? |
1161 | ELEMENTSOF(protect_system_strict_table) : | |
1162 | ((protect_system == PROTECT_SYSTEM_FULL) ? | |
1163 | ELEMENTSOF(protect_system_full_table) : | |
1164 | ((protect_system == PROTECT_SYSTEM_YES) ? | |
1165 | ELEMENTSOF(protect_system_yes_table) : 0))); | |
1166 | ||
b6c432ca DH |
1167 | protect_home_cnt = |
1168 | (protect_home == PROTECT_HOME_YES ? | |
1169 | ELEMENTSOF(protect_home_yes_table) : | |
1170 | ((protect_home == PROTECT_HOME_READ_ONLY) ? | |
e4da7d8c YW |
1171 | ELEMENTSOF(protect_home_read_only_table) : |
1172 | ((protect_home == PROTECT_HOME_TMPFS) ? | |
1173 | ELEMENTSOF(protect_home_tmpfs_table) : 0))); | |
b6c432ca | 1174 | |
2652c6c1 DH |
1175 | return !!tmp_dir + !!var_tmp_dir + |
1176 | strv_length(read_write_paths) + | |
1177 | strv_length(read_only_paths) + | |
1178 | strv_length(inaccessible_paths) + | |
6c47cd7d | 1179 | strv_length(empty_directories) + |
d2d6c096 | 1180 | n_bind_mounts + |
2abd4e38 | 1181 | n_temporary_filesystems + |
c575770b DH |
1182 | ns_info->private_dev + |
1183 | (ns_info->protect_kernel_tunables ? ELEMENTSOF(protect_kernel_tunables_table) : 0) + | |
c575770b | 1184 | (ns_info->protect_kernel_modules ? ELEMENTSOF(protect_kernel_modules_table) : 0) + |
94a7b275 KK |
1185 | (ns_info->protect_kernel_logs ? ELEMENTSOF(protect_kernel_logs_table) : 0) + |
1186 | (ns_info->protect_control_groups ? 1 : 0) + | |
5d997827 | 1187 | protect_home_cnt + protect_system_cnt + |
aecd5ac6 | 1188 | (ns_info->protect_hostname ? 2 : 0) + |
91dd5f7c LP |
1189 | (namespace_info_mount_apivfs(ns_info) ? ELEMENTSOF(apivfs_table) : 0) + |
1190 | !!log_namespace; | |
2652c6c1 DH |
1191 | } |
1192 | ||
da6053d0 | 1193 | static void normalize_mounts(const char *root_directory, MountEntry *mounts, size_t *n_mounts) { |
9b68367b | 1194 | assert(root_directory); |
f8b64b57 LP |
1195 | assert(n_mounts); |
1196 | assert(mounts || *n_mounts == 0); | |
1197 | ||
93bab288 | 1198 | typesafe_qsort(mounts, *n_mounts, mount_path_compare); |
f8b64b57 LP |
1199 | |
1200 | drop_duplicates(mounts, n_mounts); | |
1201 | drop_outside_root(root_directory, mounts, n_mounts); | |
1202 | drop_inaccessible(mounts, n_mounts); | |
1203 | drop_nop(mounts, n_mounts); | |
1204 | } | |
1205 | ||
c8c535d5 LP |
1206 | static bool root_read_only( |
1207 | char **read_only_paths, | |
1208 | ProtectSystem protect_system) { | |
1209 | ||
1210 | /* Determine whether the root directory is going to be read-only given the configured settings. */ | |
1211 | ||
1212 | if (protect_system == PROTECT_SYSTEM_STRICT) | |
1213 | return true; | |
1214 | ||
de46b2be | 1215 | if (prefixed_path_strv_contains(read_only_paths, "/")) |
c8c535d5 LP |
1216 | return true; |
1217 | ||
1218 | return false; | |
1219 | } | |
1220 | ||
1221 | static bool home_read_only( | |
1222 | char** read_only_paths, | |
1223 | char** inaccessible_paths, | |
1224 | char** empty_directories, | |
1225 | const BindMount *bind_mounts, | |
1226 | size_t n_bind_mounts, | |
1227 | const TemporaryFileSystem *temporary_filesystems, | |
1228 | size_t n_temporary_filesystems, | |
1229 | ProtectHome protect_home) { | |
1230 | ||
1231 | size_t i; | |
1232 | ||
1233 | /* Determine whether the /home directory is going to be read-only given the configured settings. Yes, | |
1234 | * this is a bit sloppy, since we don't bother checking for cases where / is affected by multiple | |
1235 | * settings. */ | |
1236 | ||
1237 | if (protect_home != PROTECT_HOME_NO) | |
1238 | return true; | |
1239 | ||
de46b2be TM |
1240 | if (prefixed_path_strv_contains(read_only_paths, "/home") || |
1241 | prefixed_path_strv_contains(inaccessible_paths, "/home") || | |
1242 | prefixed_path_strv_contains(empty_directories, "/home")) | |
c8c535d5 LP |
1243 | return true; |
1244 | ||
1245 | for (i = 0; i < n_temporary_filesystems; i++) | |
1246 | if (path_equal(temporary_filesystems[i].path, "/home")) | |
1247 | return true; | |
1248 | ||
1249 | /* If /home is overmounted with some dir from the host it's not writable. */ | |
1250 | for (i = 0; i < n_bind_mounts; i++) | |
1251 | if (path_equal(bind_mounts[i].destination, "/home")) | |
1252 | return true; | |
1253 | ||
1254 | return false; | |
1255 | } | |
1256 | ||
613b411c | 1257 | int setup_namespace( |
ee818b89 | 1258 | const char* root_directory, |
915e6d16 | 1259 | const char* root_image, |
bb0ff3fb | 1260 | const NamespaceInfo *ns_info, |
2a624c36 AP |
1261 | char** read_write_paths, |
1262 | char** read_only_paths, | |
1263 | char** inaccessible_paths, | |
6c47cd7d | 1264 | char** empty_directories, |
d2d6c096 | 1265 | const BindMount *bind_mounts, |
da6053d0 | 1266 | size_t n_bind_mounts, |
2abd4e38 | 1267 | const TemporaryFileSystem *temporary_filesystems, |
da6053d0 | 1268 | size_t n_temporary_filesystems, |
a004cb4c LP |
1269 | const char* tmp_dir, |
1270 | const char* var_tmp_dir, | |
91dd5f7c | 1271 | const char *log_namespace, |
1b8689f9 LP |
1272 | ProtectHome protect_home, |
1273 | ProtectSystem protect_system, | |
915e6d16 | 1274 | unsigned long mount_flags, |
0389f4fa LB |
1275 | const void *root_hash, |
1276 | size_t root_hash_size, | |
1277 | const char *root_hash_path, | |
d4d55b0d LB |
1278 | const void *root_hash_sig, |
1279 | size_t root_hash_sig_size, | |
1280 | const char *root_hash_sig_path, | |
0389f4fa | 1281 | const char *root_verity, |
7cc5ef5f ZJS |
1282 | DissectImageFlags dissect_image_flags, |
1283 | char **error_path) { | |
15ae422b | 1284 | |
915e6d16 | 1285 | _cleanup_(loop_device_unrefp) LoopDevice *loop_device = NULL; |
78ebe980 | 1286 | _cleanup_(decrypted_image_unrefp) DecryptedImage *decrypted_image = NULL; |
915e6d16 | 1287 | _cleanup_(dissected_image_unrefp) DissectedImage *dissected_image = NULL; |
0389f4fa | 1288 | _cleanup_free_ void *root_hash_decoded = NULL; |
c2923fdc | 1289 | _cleanup_free_ char *verity_data = NULL, *hash_sig_path = NULL; |
5f7a690a | 1290 | MountEntry *m = NULL, *mounts = NULL; |
0389f4fa | 1291 | size_t n_mounts; |
d18aff04 | 1292 | bool require_prefix = false; |
9b68367b | 1293 | const char *root; |
c17ec25e | 1294 | int r = 0; |
15ae422b | 1295 | |
915e6d16 LP |
1296 | assert(ns_info); |
1297 | ||
613b411c | 1298 | if (mount_flags == 0) |
c17ec25e | 1299 | mount_flags = MS_SHARED; |
ac0930c8 | 1300 | |
915e6d16 LP |
1301 | if (root_image) { |
1302 | dissect_image_flags |= DISSECT_IMAGE_REQUIRE_ROOT; | |
1303 | ||
c8c535d5 LP |
1304 | /* Make the whole image read-only if we can determine that we only access it in a read-only fashion. */ |
1305 | if (root_read_only(read_only_paths, | |
1306 | protect_system) && | |
1307 | home_read_only(read_only_paths, inaccessible_paths, empty_directories, | |
1308 | bind_mounts, n_bind_mounts, temporary_filesystems, n_temporary_filesystems, | |
1309 | protect_home) && | |
c9ef8573 | 1310 | strv_isempty(read_write_paths)) |
915e6d16 LP |
1311 | dissect_image_flags |= DISSECT_IMAGE_READ_ONLY; |
1312 | ||
1313 | r = loop_device_make_by_path(root_image, | |
b0a94268 | 1314 | FLAGS_SET(dissect_image_flags, DISSECT_IMAGE_READ_ONLY) ? O_RDONLY : -1 /* < 0 means writable if possible, read-only as fallback */, |
e08f94ac | 1315 | LO_FLAGS_PARTSCAN, |
915e6d16 LP |
1316 | &loop_device); |
1317 | if (r < 0) | |
763a260a | 1318 | return log_debug_errno(r, "Failed to create loop device for root image: %m"); |
915e6d16 | 1319 | |
cbc056c8 ZJS |
1320 | r = verity_metadata_load(root_image, |
1321 | root_hash_path, | |
1322 | root_hash ? NULL : &root_hash_decoded, | |
1323 | root_hash ? NULL : &root_hash_size, | |
1324 | root_verity ? NULL : &verity_data, | |
1325 | root_hash_sig || root_hash_sig_path ? NULL : &hash_sig_path); | |
78ebe980 | 1326 | if (r < 0) |
763a260a | 1327 | return log_debug_errno(r, "Failed to load root hash: %m"); |
0389f4fa | 1328 | dissect_image_flags |= root_verity || verity_data ? DISSECT_IMAGE_NO_PARTITION_TABLE : 0; |
78ebe980 | 1329 | |
cbc056c8 ZJS |
1330 | r = dissect_image(loop_device->fd, |
1331 | root_hash ?: root_hash_decoded, | |
1332 | root_hash_size, | |
1333 | root_verity ?: verity_data, | |
1334 | dissect_image_flags, | |
1335 | &dissected_image); | |
78ebe980 | 1336 | if (r < 0) |
763a260a | 1337 | return log_debug_errno(r, "Failed to dissect image: %m"); |
78ebe980 | 1338 | |
cbc056c8 ZJS |
1339 | r = dissected_image_decrypt(dissected_image, |
1340 | NULL, | |
1341 | root_hash ?: root_hash_decoded, | |
1342 | root_hash_size, | |
1343 | root_verity ?: verity_data, | |
1344 | root_hash_sig_path ?: hash_sig_path, | |
1345 | root_hash_sig, | |
1346 | root_hash_sig_size, | |
1347 | dissect_image_flags, | |
1348 | &decrypted_image); | |
915e6d16 | 1349 | if (r < 0) |
763a260a | 1350 | return log_debug_errno(r, "Failed to decrypt dissected image: %m"); |
915e6d16 LP |
1351 | } |
1352 | ||
e908468b LP |
1353 | if (root_directory) |
1354 | root = root_directory; | |
0722b359 JS |
1355 | else { |
1356 | /* Always create the mount namespace in a temporary directory, instead of operating | |
1357 | * directly in the root. The temporary directory prevents any mounts from being | |
1358 | * potentially obscured my other mounts we already applied. | |
1359 | * We use the same mount point for all images, which is safe, since they all live | |
1360 | * in their own namespaces after all, and hence won't see each other. */ | |
e908468b LP |
1361 | |
1362 | root = "/run/systemd/unit-root"; | |
1363 | (void) mkdir_label(root, 0700); | |
d18aff04 | 1364 | require_prefix = true; |
0722b359 | 1365 | } |
e908468b | 1366 | |
cfbeb4ef LP |
1367 | n_mounts = namespace_calculate_mounts( |
1368 | ns_info, | |
1369 | read_write_paths, | |
1370 | read_only_paths, | |
1371 | inaccessible_paths, | |
6c47cd7d | 1372 | empty_directories, |
f5c52a77 | 1373 | n_bind_mounts, |
2abd4e38 | 1374 | n_temporary_filesystems, |
cfbeb4ef | 1375 | tmp_dir, var_tmp_dir, |
91dd5f7c | 1376 | log_namespace, |
cfbeb4ef | 1377 | protect_home, protect_system); |
613b411c | 1378 | |
f0a4feb0 | 1379 | if (n_mounts > 0) { |
5f7a690a LP |
1380 | m = mounts = new0(MountEntry, n_mounts); |
1381 | if (!mounts) | |
1382 | return -ENOMEM; | |
1383 | ||
d18aff04 | 1384 | r = append_access_mounts(&m, read_write_paths, READWRITE, require_prefix); |
613b411c | 1385 | if (r < 0) |
f0a4feb0 | 1386 | goto finish; |
613b411c | 1387 | |
d18aff04 | 1388 | r = append_access_mounts(&m, read_only_paths, READONLY, require_prefix); |
613b411c | 1389 | if (r < 0) |
f0a4feb0 | 1390 | goto finish; |
613b411c | 1391 | |
d18aff04 | 1392 | r = append_access_mounts(&m, inaccessible_paths, INACCESSIBLE, require_prefix); |
613b411c | 1393 | if (r < 0) |
f0a4feb0 | 1394 | goto finish; |
7ff7394d | 1395 | |
6c47cd7d LP |
1396 | r = append_empty_dir_mounts(&m, empty_directories); |
1397 | if (r < 0) | |
1398 | goto finish; | |
1399 | ||
d2d6c096 LP |
1400 | r = append_bind_mounts(&m, bind_mounts, n_bind_mounts); |
1401 | if (r < 0) | |
1402 | goto finish; | |
1403 | ||
2abd4e38 YW |
1404 | r = append_tmpfs_mounts(&m, temporary_filesystems, n_temporary_filesystems); |
1405 | if (r < 0) | |
1406 | goto finish; | |
1407 | ||
613b411c | 1408 | if (tmp_dir) { |
56a13a49 ZJS |
1409 | bool ro = streq(tmp_dir, RUN_SYSTEMD_EMPTY); |
1410 | ||
34de407a | 1411 | *(m++) = (MountEntry) { |
5327c910 | 1412 | .path_const = "/tmp", |
56a13a49 | 1413 | .mode = ro ? PRIVATE_TMP_READONLY : PRIVATE_TMP, |
89bd586c | 1414 | .source_const = tmp_dir, |
5327c910 | 1415 | }; |
613b411c | 1416 | } |
7ff7394d | 1417 | |
613b411c | 1418 | if (var_tmp_dir) { |
56a13a49 ZJS |
1419 | bool ro = streq(var_tmp_dir, RUN_SYSTEMD_EMPTY); |
1420 | ||
34de407a | 1421 | *(m++) = (MountEntry) { |
5327c910 | 1422 | .path_const = "/var/tmp", |
56a13a49 | 1423 | .mode = ro ? PRIVATE_TMP_READONLY : PRIVATE_TMP, |
89bd586c | 1424 | .source_const = var_tmp_dir, |
5327c910 | 1425 | }; |
7ff7394d | 1426 | } |
ac0930c8 | 1427 | |
c575770b | 1428 | if (ns_info->private_dev) { |
34de407a | 1429 | *(m++) = (MountEntry) { |
5327c910 LP |
1430 | .path_const = "/dev", |
1431 | .mode = PRIVATE_DEV, | |
9ce4e4b0 | 1432 | .flags = DEV_MOUNT_OPTIONS, |
5327c910 | 1433 | }; |
7f112f50 LP |
1434 | } |
1435 | ||
c575770b | 1436 | if (ns_info->protect_kernel_tunables) { |
cbc056c8 ZJS |
1437 | r = append_static_mounts(&m, |
1438 | protect_kernel_tunables_table, | |
1439 | ELEMENTSOF(protect_kernel_tunables_table), | |
1440 | ns_info->ignore_protect_paths); | |
c575770b | 1441 | if (r < 0) |
f0a4feb0 | 1442 | goto finish; |
c575770b DH |
1443 | } |
1444 | ||
1445 | if (ns_info->protect_kernel_modules) { | |
cbc056c8 ZJS |
1446 | r = append_static_mounts(&m, |
1447 | protect_kernel_modules_table, | |
1448 | ELEMENTSOF(protect_kernel_modules_table), | |
1449 | ns_info->ignore_protect_paths); | |
c575770b | 1450 | if (r < 0) |
f0a4feb0 | 1451 | goto finish; |
c575770b | 1452 | } |
59eeb84b | 1453 | |
94a7b275 | 1454 | if (ns_info->protect_kernel_logs) { |
cbc056c8 ZJS |
1455 | r = append_static_mounts(&m, |
1456 | protect_kernel_logs_table, | |
1457 | ELEMENTSOF(protect_kernel_logs_table), | |
1458 | ns_info->ignore_protect_paths); | |
94a7b275 KK |
1459 | if (r < 0) |
1460 | goto finish; | |
1461 | } | |
1462 | ||
c575770b | 1463 | if (ns_info->protect_control_groups) { |
34de407a | 1464 | *(m++) = (MountEntry) { |
5327c910 LP |
1465 | .path_const = "/sys/fs/cgroup", |
1466 | .mode = READONLY, | |
1467 | }; | |
59eeb84b LP |
1468 | } |
1469 | ||
5327c910 | 1470 | r = append_protect_home(&m, protect_home, ns_info->ignore_protect_paths); |
b6c432ca | 1471 | if (r < 0) |
f0a4feb0 | 1472 | goto finish; |
417116f2 | 1473 | |
5327c910 | 1474 | r = append_protect_system(&m, protect_system, false); |
f471b2af | 1475 | if (r < 0) |
f0a4feb0 | 1476 | goto finish; |
417116f2 | 1477 | |
9b68367b | 1478 | if (namespace_info_mount_apivfs(ns_info)) { |
cbc056c8 ZJS |
1479 | r = append_static_mounts(&m, |
1480 | apivfs_table, | |
1481 | ELEMENTSOF(apivfs_table), | |
1482 | ns_info->ignore_protect_paths); | |
5d997827 LP |
1483 | if (r < 0) |
1484 | goto finish; | |
1485 | } | |
1486 | ||
aecd5ac6 TM |
1487 | if (ns_info->protect_hostname) { |
1488 | *(m++) = (MountEntry) { | |
1489 | .path_const = "/proc/sys/kernel/hostname", | |
1490 | .mode = READONLY, | |
1491 | }; | |
1492 | *(m++) = (MountEntry) { | |
1493 | .path_const = "/proc/sys/kernel/domainname", | |
1494 | .mode = READONLY, | |
1495 | }; | |
1496 | } | |
1497 | ||
91dd5f7c LP |
1498 | if (log_namespace) { |
1499 | _cleanup_free_ char *q; | |
1500 | ||
1501 | q = strjoin("/run/systemd/journal.", log_namespace); | |
1502 | if (!q) { | |
1503 | r = -ENOMEM; | |
1504 | goto finish; | |
1505 | } | |
1506 | ||
1507 | *(m++) = (MountEntry) { | |
1508 | .path_const = "/run/systemd/journal", | |
1509 | .mode = BIND_MOUNT_RECURSIVE, | |
1510 | .read_only = true, | |
1511 | .source_malloc = TAKE_PTR(q), | |
1512 | }; | |
1513 | } | |
1514 | ||
f0a4feb0 | 1515 | assert(mounts + n_mounts == m); |
ac0930c8 | 1516 | |
5327c910 | 1517 | /* Prepend the root directory where that's necessary */ |
e908468b | 1518 | r = prefix_where_needed(mounts, n_mounts, root); |
5327c910 LP |
1519 | if (r < 0) |
1520 | goto finish; | |
1521 | ||
839f1877 | 1522 | normalize_mounts(root, mounts, &n_mounts); |
15ae422b LP |
1523 | } |
1524 | ||
1beab8b0 LP |
1525 | /* All above is just preparation, figuring out what to do. Let's now actually start doing something. */ |
1526 | ||
d944dc95 | 1527 | if (unshare(CLONE_NEWNS) < 0) { |
763a260a | 1528 | r = log_debug_errno(errno, "Failed to unshare the mount namespace: %m"); |
1beab8b0 | 1529 | if (IN_SET(r, -EACCES, -EPERM, -EOPNOTSUPP, -ENOSYS)) |
cbc056c8 ZJS |
1530 | /* If the kernel doesn't support namespaces, or when there's a MAC or seccomp filter |
1531 | * in place that doesn't allow us to create namespaces (or a missing cap), then | |
1532 | * propagate a recognizable error back, which the caller can use to detect this case | |
1533 | * (and only this) and optionally continue without namespacing applied. */ | |
1beab8b0 LP |
1534 | r = -ENOANO; |
1535 | ||
d944dc95 LP |
1536 | goto finish; |
1537 | } | |
1e4e94c8 | 1538 | |
9b68367b YW |
1539 | /* Remount / as SLAVE so that nothing now mounted in the namespace |
1540 | * shows up in the parent */ | |
1541 | if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) { | |
763a260a | 1542 | r = log_debug_errno(errno, "Failed to remount '/' as SLAVE: %m"); |
9b68367b | 1543 | goto finish; |
ee818b89 AC |
1544 | } |
1545 | ||
915e6d16 | 1546 | if (root_image) { |
e908468b | 1547 | /* A root image is specified, mount it to the right place */ |
2d3a5a73 | 1548 | r = dissected_image_mount(dissected_image, root, UID_INVALID, dissect_image_flags); |
763a260a YW |
1549 | if (r < 0) { |
1550 | log_debug_errno(r, "Failed to mount root image: %m"); | |
915e6d16 | 1551 | goto finish; |
763a260a | 1552 | } |
915e6d16 | 1553 | |
07ce7407 TM |
1554 | if (decrypted_image) { |
1555 | r = decrypted_image_relinquish(decrypted_image); | |
763a260a YW |
1556 | if (r < 0) { |
1557 | log_debug_errno(r, "Failed to relinquish decrypted image: %m"); | |
07ce7407 | 1558 | goto finish; |
763a260a | 1559 | } |
07ce7407 | 1560 | } |
78ebe980 | 1561 | |
915e6d16 LP |
1562 | loop_device_relinquish(loop_device); |
1563 | ||
1564 | } else if (root_directory) { | |
1565 | ||
e908468b LP |
1566 | /* A root directory is specified. Turn its directory into bind mount, if it isn't one yet. */ |
1567 | r = path_is_mount_point(root, NULL, AT_SYMLINK_FOLLOW); | |
763a260a YW |
1568 | if (r < 0) { |
1569 | log_debug_errno(r, "Failed to detect that %s is a mount point or not: %m", root); | |
d944dc95 | 1570 | goto finish; |
763a260a | 1571 | } |
8f1ad200 | 1572 | if (r == 0) { |
e908468b | 1573 | if (mount(root, root, NULL, MS_BIND|MS_REC, NULL) < 0) { |
763a260a | 1574 | r = log_debug_errno(errno, "Failed to bind mount '%s': %m", root); |
8f1ad200 LP |
1575 | goto finish; |
1576 | } | |
d944dc95 | 1577 | } |
e908468b | 1578 | |
9b68367b | 1579 | } else { |
e908468b LP |
1580 | |
1581 | /* Let's mount the main root directory to the root directory to use */ | |
1582 | if (mount("/", root, NULL, MS_BIND|MS_REC, NULL) < 0) { | |
763a260a | 1583 | r = log_debug_errno(errno, "Failed to bind mount '/' on '%s': %m", root); |
e908468b LP |
1584 | goto finish; |
1585 | } | |
ee818b89 | 1586 | } |
c2c13f2d | 1587 | |
4e0c20de LP |
1588 | /* Try to set up the new root directory before mounting anything else there. */ |
1589 | if (root_image || root_directory) | |
1590 | (void) base_filesystem_create(root, UID_INVALID, GID_INVALID); | |
1591 | ||
f0a4feb0 | 1592 | if (n_mounts > 0) { |
ac9de0b3 | 1593 | _cleanup_fclose_ FILE *proc_self_mountinfo = NULL; |
6b000af4 | 1594 | _cleanup_free_ char **deny_list = NULL; |
da6053d0 | 1595 | size_t j; |
6b7c9f8b | 1596 | |
cbc056c8 ZJS |
1597 | /* Open /proc/self/mountinfo now as it may become unavailable if we mount anything on top of |
1598 | * /proc. For example, this is the case with the option: 'InaccessiblePaths=/proc'. */ | |
ac9de0b3 TR |
1599 | proc_self_mountinfo = fopen("/proc/self/mountinfo", "re"); |
1600 | if (!proc_self_mountinfo) { | |
763a260a | 1601 | r = log_debug_errno(errno, "Failed to open /proc/self/mountinfo: %m"); |
7cc5ef5f ZJS |
1602 | if (error_path) |
1603 | *error_path = strdup("/proc/self/mountinfo"); | |
ac9de0b3 TR |
1604 | goto finish; |
1605 | } | |
1606 | ||
088696fe LP |
1607 | /* First round, establish all mounts we need */ |
1608 | for (;;) { | |
1609 | bool again = false; | |
1610 | ||
1611 | for (m = mounts; m < mounts + n_mounts; ++m) { | |
1612 | ||
1613 | if (m->applied) | |
1614 | continue; | |
1615 | ||
1616 | r = follow_symlink(root, m); | |
7cc5ef5f ZJS |
1617 | if (r < 0) { |
1618 | if (error_path && mount_entry_path(m)) | |
1619 | *error_path = strdup(mount_entry_path(m)); | |
088696fe | 1620 | goto finish; |
7cc5ef5f | 1621 | } |
088696fe | 1622 | if (r == 0) { |
cbc056c8 ZJS |
1623 | /* We hit a symlinked mount point. The entry got rewritten and might |
1624 | * point to a very different place now. Let's normalize the changed | |
1625 | * list, and start from the beginning. After all to mount the entry | |
1626 | * at the new location we might need some other mounts first */ | |
088696fe LP |
1627 | again = true; |
1628 | break; | |
1629 | } | |
1630 | ||
1631 | r = apply_mount(root, m); | |
7cc5ef5f ZJS |
1632 | if (r < 0) { |
1633 | if (error_path && mount_entry_path(m)) | |
1634 | *error_path = strdup(mount_entry_path(m)); | |
088696fe | 1635 | goto finish; |
7cc5ef5f | 1636 | } |
088696fe LP |
1637 | |
1638 | m->applied = true; | |
1639 | } | |
1640 | ||
1641 | if (!again) | |
1642 | break; | |
1643 | ||
839f1877 | 1644 | normalize_mounts(root, mounts, &n_mounts); |
c2c13f2d | 1645 | } |
15ae422b | 1646 | |
6b000af4 LP |
1647 | /* Create a deny list we can pass to bind_mount_recursive() */ |
1648 | deny_list = new(char*, n_mounts+1); | |
1649 | if (!deny_list) { | |
5f7a690a LP |
1650 | r = -ENOMEM; |
1651 | goto finish; | |
1652 | } | |
f0a4feb0 | 1653 | for (j = 0; j < n_mounts; j++) |
6b000af4 LP |
1654 | deny_list[j] = (char*) mount_entry_path(mounts+j); |
1655 | deny_list[j] = NULL; | |
6b7c9f8b LP |
1656 | |
1657 | /* Second round, flip the ro bits if necessary. */ | |
f0a4feb0 | 1658 | for (m = mounts; m < mounts + n_mounts; ++m) { |
6b000af4 | 1659 | r = make_read_only(m, deny_list, proc_self_mountinfo); |
7cc5ef5f ZJS |
1660 | if (r < 0) { |
1661 | if (error_path && mount_entry_path(m)) | |
1662 | *error_path = strdup(mount_entry_path(m)); | |
d944dc95 | 1663 | goto finish; |
7cc5ef5f | 1664 | } |
c2c13f2d | 1665 | } |
15ae422b LP |
1666 | } |
1667 | ||
9b68367b YW |
1668 | /* MS_MOVE does not work on MS_SHARED so the remount MS_SHARED will be done later */ |
1669 | r = mount_move_root(root); | |
763a260a YW |
1670 | if (r < 0) { |
1671 | log_debug_errno(r, "Failed to mount root with MS_MOVE: %m"); | |
9b68367b | 1672 | goto finish; |
763a260a | 1673 | } |
ee818b89 | 1674 | |
55fe7432 | 1675 | /* Remount / as the desired mode. Note that this will not |
c2c13f2d LP |
1676 | * reestablish propagation from our side to the host, since |
1677 | * what's disconnected is disconnected. */ | |
d944dc95 | 1678 | if (mount(NULL, "/", NULL, mount_flags | MS_REC, NULL) < 0) { |
763a260a | 1679 | r = log_debug_errno(errno, "Failed to remount '/' with desired mount flags: %m"); |
d944dc95 LP |
1680 | goto finish; |
1681 | } | |
15ae422b | 1682 | |
d944dc95 | 1683 | r = 0; |
15ae422b | 1684 | |
d944dc95 | 1685 | finish: |
0cd41757 LP |
1686 | if (n_mounts > 0) |
1687 | for (m = mounts; m < mounts + n_mounts; m++) | |
1688 | mount_entry_done(m); | |
613b411c | 1689 | |
5f7a690a LP |
1690 | free(mounts); |
1691 | ||
613b411c LP |
1692 | return r; |
1693 | } | |
1694 | ||
da6053d0 LP |
1695 | void bind_mount_free_many(BindMount *b, size_t n) { |
1696 | size_t i; | |
d2d6c096 LP |
1697 | |
1698 | assert(b || n == 0); | |
1699 | ||
1700 | for (i = 0; i < n; i++) { | |
1701 | free(b[i].source); | |
1702 | free(b[i].destination); | |
1703 | } | |
1704 | ||
1705 | free(b); | |
1706 | } | |
1707 | ||
da6053d0 | 1708 | int bind_mount_add(BindMount **b, size_t *n, const BindMount *item) { |
d2d6c096 LP |
1709 | _cleanup_free_ char *s = NULL, *d = NULL; |
1710 | BindMount *c; | |
1711 | ||
1712 | assert(b); | |
1713 | assert(n); | |
1714 | assert(item); | |
1715 | ||
1716 | s = strdup(item->source); | |
1717 | if (!s) | |
1718 | return -ENOMEM; | |
1719 | ||
1720 | d = strdup(item->destination); | |
1721 | if (!d) | |
1722 | return -ENOMEM; | |
1723 | ||
aa484f35 | 1724 | c = reallocarray(*b, *n + 1, sizeof(BindMount)); |
d2d6c096 LP |
1725 | if (!c) |
1726 | return -ENOMEM; | |
1727 | ||
1728 | *b = c; | |
1729 | ||
1730 | c[(*n) ++] = (BindMount) { | |
1cc6c93a YW |
1731 | .source = TAKE_PTR(s), |
1732 | .destination = TAKE_PTR(d), | |
d2d6c096 | 1733 | .read_only = item->read_only, |
9ce4e4b0 | 1734 | .nosuid = item->nosuid, |
d2d6c096 LP |
1735 | .recursive = item->recursive, |
1736 | .ignore_enoent = item->ignore_enoent, | |
1737 | }; | |
1738 | ||
d2d6c096 LP |
1739 | return 0; |
1740 | } | |
1741 | ||
da6053d0 LP |
1742 | void temporary_filesystem_free_many(TemporaryFileSystem *t, size_t n) { |
1743 | size_t i; | |
2abd4e38 YW |
1744 | |
1745 | assert(t || n == 0); | |
1746 | ||
1747 | for (i = 0; i < n; i++) { | |
1748 | free(t[i].path); | |
1749 | free(t[i].options); | |
1750 | } | |
1751 | ||
1752 | free(t); | |
1753 | } | |
1754 | ||
1755 | int temporary_filesystem_add( | |
1756 | TemporaryFileSystem **t, | |
da6053d0 | 1757 | size_t *n, |
2abd4e38 YW |
1758 | const char *path, |
1759 | const char *options) { | |
1760 | ||
1761 | _cleanup_free_ char *p = NULL, *o = NULL; | |
1762 | TemporaryFileSystem *c; | |
1763 | ||
1764 | assert(t); | |
1765 | assert(n); | |
1766 | assert(path); | |
1767 | ||
1768 | p = strdup(path); | |
1769 | if (!p) | |
1770 | return -ENOMEM; | |
1771 | ||
1772 | if (!isempty(options)) { | |
1773 | o = strdup(options); | |
1774 | if (!o) | |
1775 | return -ENOMEM; | |
1776 | } | |
1777 | ||
aa484f35 | 1778 | c = reallocarray(*t, *n + 1, sizeof(TemporaryFileSystem)); |
2abd4e38 YW |
1779 | if (!c) |
1780 | return -ENOMEM; | |
1781 | ||
1782 | *t = c; | |
1783 | ||
1784 | c[(*n) ++] = (TemporaryFileSystem) { | |
1cc6c93a YW |
1785 | .path = TAKE_PTR(p), |
1786 | .options = TAKE_PTR(o), | |
2abd4e38 YW |
1787 | }; |
1788 | ||
2abd4e38 YW |
1789 | return 0; |
1790 | } | |
1791 | ||
a652f050 JR |
1792 | static int make_tmp_prefix(const char *prefix) { |
1793 | _cleanup_free_ char *t = NULL; | |
1794 | int r; | |
1795 | ||
1796 | /* Don't do anything unless we know the dir is actually missing */ | |
1797 | r = access(prefix, F_OK); | |
1798 | if (r >= 0) | |
1799 | return 0; | |
1800 | if (errno != ENOENT) | |
1801 | return -errno; | |
1802 | ||
1803 | r = mkdir_parents(prefix, 0755); | |
1804 | if (r < 0) | |
1805 | return r; | |
1806 | ||
1807 | r = tempfn_random(prefix, NULL, &t); | |
1808 | if (r < 0) | |
1809 | return r; | |
1810 | ||
1811 | if (mkdir(t, 0777) < 0) | |
1812 | return -errno; | |
1813 | ||
1814 | if (chmod(t, 01777) < 0) { | |
1815 | r = -errno; | |
1816 | (void) rmdir(t); | |
1817 | return r; | |
1818 | } | |
1819 | ||
1820 | if (rename(t, prefix) < 0) { | |
1821 | r = -errno; | |
1822 | (void) rmdir(t); | |
1823 | return r == -EEXIST ? 0 : r; /* it's fine if someone else created the dir by now */ | |
1824 | } | |
1825 | ||
1826 | return 0; | |
1827 | ||
1828 | } | |
1829 | ||
56a13a49 ZJS |
1830 | static int make_tmp_subdir(const char *parent, char **ret) { |
1831 | _cleanup_free_ char *y = NULL; | |
1832 | ||
1833 | RUN_WITH_UMASK(0000) { | |
1834 | y = strjoin(parent, "/tmp"); | |
1835 | if (!y) | |
1836 | return -ENOMEM; | |
1837 | ||
1838 | if (mkdir(y, 0777 | S_ISVTX) < 0) | |
1839 | return -errno; | |
1840 | } | |
1841 | ||
1842 | if (ret) | |
1843 | *ret = TAKE_PTR(y); | |
1844 | return 0; | |
1845 | } | |
1846 | ||
1847 | static int setup_one_tmp_dir(const char *id, const char *prefix, char **path, char **tmp_path) { | |
613b411c | 1848 | _cleanup_free_ char *x = NULL; |
6b46ea73 LP |
1849 | char bid[SD_ID128_STRING_MAX]; |
1850 | sd_id128_t boot_id; | |
56a13a49 | 1851 | bool rw = true; |
6b46ea73 | 1852 | int r; |
613b411c LP |
1853 | |
1854 | assert(id); | |
1855 | assert(prefix); | |
1856 | assert(path); | |
1857 | ||
6b46ea73 LP |
1858 | /* We include the boot id in the directory so that after a |
1859 | * reboot we can easily identify obsolete directories. */ | |
1860 | ||
1861 | r = sd_id128_get_boot(&boot_id); | |
1862 | if (r < 0) | |
1863 | return r; | |
1864 | ||
605405c6 | 1865 | x = strjoin(prefix, "/systemd-private-", sd_id128_to_string(boot_id, bid), "-", id, "-XXXXXX"); |
613b411c LP |
1866 | if (!x) |
1867 | return -ENOMEM; | |
1868 | ||
a652f050 JR |
1869 | r = make_tmp_prefix(prefix); |
1870 | if (r < 0) | |
1871 | return r; | |
1872 | ||
613b411c | 1873 | RUN_WITH_UMASK(0077) |
56a13a49 ZJS |
1874 | if (!mkdtemp(x)) { |
1875 | if (errno == EROFS || ERRNO_IS_DISK_SPACE(errno)) | |
1876 | rw = false; | |
1877 | else | |
1878 | return -errno; | |
1879 | } | |
613b411c | 1880 | |
56a13a49 ZJS |
1881 | if (rw) { |
1882 | r = make_tmp_subdir(x, tmp_path); | |
1883 | if (r < 0) | |
1884 | return r; | |
1885 | } else { | |
1886 | /* Trouble: we failed to create the directory. Instead of failing, let's simulate /tmp being | |
1887 | * read-only. This way the service will get the EROFS result as if it was writing to the real | |
1888 | * file system. */ | |
1889 | r = mkdir_p(RUN_SYSTEMD_EMPTY, 0500); | |
1890 | if (r < 0) | |
1891 | return r; | |
613b411c | 1892 | |
56a13a49 ZJS |
1893 | x = strdup(RUN_SYSTEMD_EMPTY); |
1894 | if (!x) | |
1895 | return -ENOMEM; | |
c17ec25e | 1896 | } |
15ae422b | 1897 | |
1cc6c93a | 1898 | *path = TAKE_PTR(x); |
613b411c LP |
1899 | return 0; |
1900 | } | |
1901 | ||
1902 | int setup_tmp_dirs(const char *id, char **tmp_dir, char **var_tmp_dir) { | |
56a13a49 ZJS |
1903 | _cleanup_(namespace_cleanup_tmpdirp) char *a = NULL; |
1904 | _cleanup_(rmdir_and_freep) char *a_tmp = NULL; | |
1905 | char *b; | |
613b411c LP |
1906 | int r; |
1907 | ||
1908 | assert(id); | |
1909 | assert(tmp_dir); | |
1910 | assert(var_tmp_dir); | |
1911 | ||
56a13a49 | 1912 | r = setup_one_tmp_dir(id, "/tmp", &a, &a_tmp); |
613b411c LP |
1913 | if (r < 0) |
1914 | return r; | |
1915 | ||
56a13a49 ZJS |
1916 | r = setup_one_tmp_dir(id, "/var/tmp", &b, NULL); |
1917 | if (r < 0) | |
613b411c | 1918 | return r; |
613b411c | 1919 | |
56a13a49 ZJS |
1920 | a_tmp = mfree(a_tmp); /* avoid rmdir */ |
1921 | *tmp_dir = TAKE_PTR(a); | |
1922 | *var_tmp_dir = TAKE_PTR(b); | |
613b411c LP |
1923 | |
1924 | return 0; | |
1925 | } | |
1926 | ||
2caa38e9 | 1927 | int setup_netns(const int netns_storage_socket[static 2]) { |
613b411c | 1928 | _cleanup_close_ int netns = -1; |
3ee897d6 | 1929 | int r, q; |
613b411c LP |
1930 | |
1931 | assert(netns_storage_socket); | |
1932 | assert(netns_storage_socket[0] >= 0); | |
1933 | assert(netns_storage_socket[1] >= 0); | |
1934 | ||
1935 | /* We use the passed socketpair as a storage buffer for our | |
76cd584b LP |
1936 | * namespace reference fd. Whatever process runs this first |
1937 | * shall create a new namespace, all others should just join | |
1938 | * it. To serialize that we use a file lock on the socket | |
1939 | * pair. | |
613b411c LP |
1940 | * |
1941 | * It's a bit crazy, but hey, works great! */ | |
1942 | ||
1943 | if (lockf(netns_storage_socket[0], F_LOCK, 0) < 0) | |
1944 | return -errno; | |
1945 | ||
3ee897d6 LP |
1946 | netns = receive_one_fd(netns_storage_socket[0], MSG_DONTWAIT); |
1947 | if (netns == -EAGAIN) { | |
44ffcbae | 1948 | /* Nothing stored yet, so let's create a new namespace. */ |
613b411c LP |
1949 | |
1950 | if (unshare(CLONE_NEWNET) < 0) { | |
1951 | r = -errno; | |
1952 | goto fail; | |
1953 | } | |
1954 | ||
44ffcbae | 1955 | (void) loopback_setup(); |
613b411c LP |
1956 | |
1957 | netns = open("/proc/self/ns/net", O_RDONLY|O_CLOEXEC|O_NOCTTY); | |
1958 | if (netns < 0) { | |
1959 | r = -errno; | |
1960 | goto fail; | |
1961 | } | |
1962 | ||
1963 | r = 1; | |
613b411c | 1964 | |
3ee897d6 LP |
1965 | } else if (netns < 0) { |
1966 | r = netns; | |
1967 | goto fail; | |
613b411c | 1968 | |
3ee897d6 LP |
1969 | } else { |
1970 | /* Yay, found something, so let's join the namespace */ | |
613b411c LP |
1971 | if (setns(netns, CLONE_NEWNET) < 0) { |
1972 | r = -errno; | |
1973 | goto fail; | |
1974 | } | |
1975 | ||
1976 | r = 0; | |
1977 | } | |
1978 | ||
3ee897d6 LP |
1979 | q = send_one_fd(netns_storage_socket[1], netns, MSG_DONTWAIT); |
1980 | if (q < 0) { | |
1981 | r = q; | |
613b411c LP |
1982 | goto fail; |
1983 | } | |
1984 | ||
1985 | fail: | |
fe048ce5 | 1986 | (void) lockf(netns_storage_socket[0], F_ULOCK, 0); |
15ae422b LP |
1987 | return r; |
1988 | } | |
417116f2 | 1989 | |
2caa38e9 | 1990 | int open_netns_path(const int netns_storage_socket[static 2], const char *path) { |
51af7fb2 LP |
1991 | _cleanup_close_ int netns = -1; |
1992 | int q, r; | |
1993 | ||
1994 | assert(netns_storage_socket); | |
1995 | assert(netns_storage_socket[0] >= 0); | |
1996 | assert(netns_storage_socket[1] >= 0); | |
1997 | assert(path); | |
1998 | ||
1999 | /* If the storage socket doesn't contain a netns fd yet, open one via the file system and store it in | |
2000 | * it. This is supposed to be called ahead of time, i.e. before setup_netns() which will allocate a | |
2001 | * new anonymous netns if needed. */ | |
2002 | ||
2003 | if (lockf(netns_storage_socket[0], F_LOCK, 0) < 0) | |
2004 | return -errno; | |
2005 | ||
2006 | netns = receive_one_fd(netns_storage_socket[0], MSG_DONTWAIT); | |
2007 | if (netns == -EAGAIN) { | |
2008 | /* Nothing stored yet. Open the file from the file system. */ | |
2009 | ||
2010 | netns = open(path, O_RDONLY|O_NOCTTY|O_CLOEXEC); | |
2011 | if (netns < 0) { | |
2012 | r = -errno; | |
2013 | goto fail; | |
2014 | } | |
2015 | ||
2016 | r = fd_is_network_ns(netns); | |
2017 | if (r == 0) { /* Not a netns? Refuse early. */ | |
2018 | r = -EINVAL; | |
2019 | goto fail; | |
2020 | } | |
2021 | if (r < 0 && r != -EUCLEAN) /* EUCLEAN: we don't know */ | |
2022 | goto fail; | |
2023 | ||
2024 | r = 1; | |
2025 | ||
2026 | } else if (netns < 0) { | |
2027 | r = netns; | |
2028 | goto fail; | |
2029 | } else | |
2030 | r = 0; /* Already allocated */ | |
2031 | ||
2032 | q = send_one_fd(netns_storage_socket[1], netns, MSG_DONTWAIT); | |
2033 | if (q < 0) { | |
2034 | r = q; | |
2035 | goto fail; | |
2036 | } | |
2037 | ||
2038 | fail: | |
2039 | (void) lockf(netns_storage_socket[0], F_ULOCK, 0); | |
2040 | return r; | |
2041 | } | |
2042 | ||
6e2d7c4f MS |
2043 | bool ns_type_supported(NamespaceType type) { |
2044 | const char *t, *ns_proc; | |
2045 | ||
0fa5b831 LP |
2046 | t = namespace_type_to_string(type); |
2047 | if (!t) /* Don't know how to translate this? Then it's not supported */ | |
6e2d7c4f MS |
2048 | return false; |
2049 | ||
6e2d7c4f | 2050 | ns_proc = strjoina("/proc/self/ns/", t); |
6e2d7c4f MS |
2051 | return access(ns_proc, F_OK) == 0; |
2052 | } | |
2053 | ||
1b8689f9 | 2054 | static const char *const protect_home_table[_PROTECT_HOME_MAX] = { |
cbc056c8 ZJS |
2055 | [PROTECT_HOME_NO] = "no", |
2056 | [PROTECT_HOME_YES] = "yes", | |
1b8689f9 | 2057 | [PROTECT_HOME_READ_ONLY] = "read-only", |
cbc056c8 | 2058 | [PROTECT_HOME_TMPFS] = "tmpfs", |
417116f2 LP |
2059 | }; |
2060 | ||
1e8c7bd5 | 2061 | DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(protect_home, ProtectHome, PROTECT_HOME_YES); |
5e1c6154 | 2062 | |
1b8689f9 | 2063 | static const char *const protect_system_table[_PROTECT_SYSTEM_MAX] = { |
cbc056c8 ZJS |
2064 | [PROTECT_SYSTEM_NO] = "no", |
2065 | [PROTECT_SYSTEM_YES] = "yes", | |
2066 | [PROTECT_SYSTEM_FULL] = "full", | |
3f815163 | 2067 | [PROTECT_SYSTEM_STRICT] = "strict", |
1b8689f9 LP |
2068 | }; |
2069 | ||
1e8c7bd5 | 2070 | DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(protect_system, ProtectSystem, PROTECT_SYSTEM_YES); |
03c791aa | 2071 | |
6e2d7c4f | 2072 | static const char* const namespace_type_table[] = { |
cbc056c8 | 2073 | [NAMESPACE_MOUNT] = "mnt", |
6e2d7c4f | 2074 | [NAMESPACE_CGROUP] = "cgroup", |
cbc056c8 ZJS |
2075 | [NAMESPACE_UTS] = "uts", |
2076 | [NAMESPACE_IPC] = "ipc", | |
2077 | [NAMESPACE_USER] = "user", | |
2078 | [NAMESPACE_PID] = "pid", | |
2079 | [NAMESPACE_NET] = "net", | |
6e2d7c4f MS |
2080 | }; |
2081 | ||
2082 | DEFINE_STRING_TABLE_LOOKUP(namespace_type, NamespaceType); |