1 /* SPDX-License-Identifier: LGPL-2.1+ */
4 #include <linux/loop.h>
11 #include "alloc-util.h"
12 #include "base-filesystem.h"
13 #include "dev-setup.h"
17 #include "loop-util.h"
18 #include "loopback-setup.h"
20 #include "mount-util.h"
21 #include "mountpoint-util.h"
22 #include "namespace-util.h"
23 #include "namespace.h"
24 #include "nulstr-util.h"
25 #include "path-util.h"
26 #include "selinux-util.h"
27 #include "socket-util.h"
28 #include "sort-util.h"
29 #include "stat-util.h"
30 #include "string-table.h"
31 #include "string-util.h"
33 #include "tmpfile-util.h"
34 #include "umask-util.h"
35 #include "user-util.h"
37 #define DEV_MOUNT_OPTIONS (MS_NOSUID|MS_STRICTATIME|MS_NOEXEC)
39 typedef enum MountMode
{
40 /* This is ordered by priority! */
53 READWRITE_IMPLICIT
, /* Should have the lowest priority. */
57 typedef struct MountEntry
{
58 const char *path_const
; /* Memory allocated on stack or static */
60 bool ignore
:1; /* Ignore if path does not exist? */
61 bool has_prefix
:1; /* Already is prefixed by the root dir? */
62 bool read_only
:1; /* Shall this mount point be read-only? */
63 bool nosuid
:1; /* Shall set MS_NOSUID on the mount itself */
64 bool applied
:1; /* Already applied */
65 char *path_malloc
; /* Use this instead of 'path_const' if we had to allocate memory */
66 const char *source_const
; /* The source path, for bind mounts */
68 const char *options_const
;/* Mount options for tmpfs */
70 unsigned long flags
; /* Mount flags used by EMPTY_DIR and TMPFS. Do not include MS_RDONLY here, but please use read_only. */
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 overridden 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 },
82 /* ProtectKernelTunables= option and the related filesystem APIs */
83 static const MountEntry protect_kernel_tunables_table
[] = {
84 { "/proc/acpi", READONLY
, true },
85 { "/proc/apm", READONLY
, true }, /* Obsolete API, there's no point in permitting access to this, ever */
86 { "/proc/asound", READONLY
, true },
87 { "/proc/bus", READONLY
, true },
88 { "/proc/fs", READONLY
, true },
89 { "/proc/irq", READONLY
, true },
90 { "/proc/kallsyms", INACCESSIBLE
, true },
91 { "/proc/kcore", INACCESSIBLE
, true },
92 { "/proc/latency_stats", READONLY
, true },
93 { "/proc/mtrr", READONLY
, true },
94 { "/proc/scsi", READONLY
, true },
95 { "/proc/sys", READONLY
, false },
96 { "/proc/sysrq-trigger", READONLY
, true },
97 { "/proc/timer_stats", READONLY
, true },
98 { "/sys", READONLY
, false },
99 { "/sys/fs/bpf", READONLY
, true },
100 { "/sys/fs/cgroup", READWRITE_IMPLICIT
, false }, /* READONLY is set by ProtectControlGroups= option */
101 { "/sys/fs/selinux", READWRITE_IMPLICIT
, true },
102 { "/sys/kernel/debug", READONLY
, true },
103 { "/sys/kernel/tracing", READONLY
, true },
106 /* ProtectKernelModules= option */
107 static const MountEntry protect_kernel_modules_table
[] = {
109 { "/lib/modules", INACCESSIBLE
, true },
111 { "/usr/lib/modules", INACCESSIBLE
, true },
114 /* ProtectKernelLogs= option */
115 static const MountEntry protect_kernel_logs_table
[] = {
116 { "/proc/kmsg", INACCESSIBLE
, true },
117 { "/dev/kmsg", INACCESSIBLE
, true },
121 * ProtectHome=read-only table, protect $HOME and $XDG_RUNTIME_DIR and rest of
122 * system should be protected by ProtectSystem=
124 static const MountEntry protect_home_read_only_table
[] = {
125 { "/home", READONLY
, true },
126 { "/run/user", READONLY
, true },
127 { "/root", READONLY
, true },
130 /* ProtectHome=tmpfs table */
131 static const MountEntry protect_home_tmpfs_table
[] = {
132 { "/home", TMPFS
, true, .read_only
= true, .options_const
= "mode=0755", .flags
= MS_NODEV
|MS_STRICTATIME
},
133 { "/run/user", TMPFS
, true, .read_only
= true, .options_const
= "mode=0755", .flags
= MS_NODEV
|MS_STRICTATIME
},
134 { "/root", TMPFS
, true, .read_only
= true, .options_const
= "mode=0700", .flags
= MS_NODEV
|MS_STRICTATIME
},
137 /* ProtectHome=yes table */
138 static const MountEntry protect_home_yes_table
[] = {
139 { "/home", INACCESSIBLE
, true },
140 { "/run/user", INACCESSIBLE
, true },
141 { "/root", INACCESSIBLE
, true },
144 /* ProtectSystem=yes table */
145 static const MountEntry protect_system_yes_table
[] = {
146 { "/usr", READONLY
, false },
147 { "/boot", READONLY
, true },
148 { "/efi", READONLY
, true },
150 { "/lib", READONLY
, true },
151 { "/lib64", READONLY
, true },
152 { "/bin", READONLY
, true },
154 { "/sbin", READONLY
, true },
159 /* ProtectSystem=full includes ProtectSystem=yes */
160 static const MountEntry protect_system_full_table
[] = {
161 { "/usr", READONLY
, false },
162 { "/boot", READONLY
, true },
163 { "/efi", READONLY
, true },
164 { "/etc", READONLY
, false },
166 { "/lib", READONLY
, true },
167 { "/lib64", READONLY
, true },
168 { "/bin", READONLY
, true },
170 { "/sbin", READONLY
, true },
176 * ProtectSystem=strict table. In this strict mode, we mount everything
177 * read-only, except for /proc, /dev, /sys which are the kernel API VFS,
178 * which are left writable, but PrivateDevices= + ProtectKernelTunables=
179 * protect those, and these options should be fully orthogonal.
180 * (And of course /home and friends are also left writable, as ProtectHome=
181 * shall manage those, orthogonally).
183 static const MountEntry protect_system_strict_table
[] = {
184 { "/", READONLY
, false },
185 { "/proc", READWRITE_IMPLICIT
, false }, /* ProtectKernelTunables= */
186 { "/sys", READWRITE_IMPLICIT
, false }, /* ProtectKernelTunables= */
187 { "/dev", READWRITE_IMPLICIT
, false }, /* PrivateDevices= */
188 { "/home", READWRITE_IMPLICIT
, true }, /* ProtectHome= */
189 { "/run/user", READWRITE_IMPLICIT
, true }, /* ProtectHome= */
190 { "/root", READWRITE_IMPLICIT
, true }, /* ProtectHome= */
193 static const char * const mount_mode_table
[_MOUNT_MODE_MAX
] = {
194 [INACCESSIBLE
] = "inaccessible",
195 [BIND_MOUNT
] = "bind",
196 [BIND_MOUNT_RECURSIVE
] = "rbind",
197 [PRIVATE_TMP
] = "private-tmp",
198 [PRIVATE_DEV
] = "private-dev",
199 [BIND_DEV
] = "bind-dev",
200 [EMPTY_DIR
] = "empty",
203 [READONLY
] = "read-only",
204 [READWRITE
] = "read-write",
206 [READWRITE_IMPLICIT
] = "rw-implicit",
209 DEFINE_PRIVATE_STRING_TABLE_LOOKUP_TO_STRING(mount_mode
, MountMode
);
211 static const char *mount_entry_path(const MountEntry
*p
) {
214 /* Returns the path of this bind mount. If the malloc()-allocated ->path_buffer field is set we return that,
215 * otherwise the stack/static ->path field is returned. */
217 return p
->path_malloc
?: p
->path_const
;
220 static bool mount_entry_read_only(const MountEntry
*p
) {
223 return p
->read_only
|| IN_SET(p
->mode
, READONLY
, INACCESSIBLE
);
226 static const char *mount_entry_source(const MountEntry
*p
) {
229 return p
->source_malloc
?: p
->source_const
;
232 static const char *mount_entry_options(const MountEntry
*p
) {
235 return p
->options_malloc
?: p
->options_const
;
238 static void mount_entry_done(MountEntry
*p
) {
241 p
->path_malloc
= mfree(p
->path_malloc
);
242 p
->source_malloc
= mfree(p
->source_malloc
);
243 p
->options_malloc
= mfree(p
->options_malloc
);
246 static int append_access_mounts(MountEntry
**p
, char **strv
, MountMode mode
, bool forcibly_require_prefix
) {
251 /* Adds a list of user-supplied READWRITE/READWRITE_IMPLICIT/READONLY/INACCESSIBLE entries */
253 STRV_FOREACH(i
, strv
) {
254 bool ignore
= false, needs_prefix
= false;
257 /* Look for any prefixes */
258 if (startswith(e
, "-")) {
262 if (startswith(e
, "+")) {
267 if (!path_is_absolute(e
))
268 return log_debug_errno(SYNTHETIC_ERRNO(EINVAL
),
269 "Path is not absolute: %s", e
);
271 *((*p
)++) = (MountEntry
) {
275 .has_prefix
= !needs_prefix
&& !forcibly_require_prefix
,
282 static int append_empty_dir_mounts(MountEntry
**p
, char **strv
) {
287 /* Adds tmpfs mounts to provide readable but empty directories. This is primarily used to implement the
288 * "/private/" boundary directories for DynamicUser=1. */
290 STRV_FOREACH(i
, strv
) {
292 *((*p
)++) = (MountEntry
) {
297 .options_const
= "mode=755",
298 .flags
= MS_NOSUID
|MS_NOEXEC
|MS_NODEV
|MS_STRICTATIME
,
305 static int append_bind_mounts(MountEntry
**p
, const BindMount
*binds
, size_t n
) {
310 for (i
= 0; i
< n
; i
++) {
311 const BindMount
*b
= binds
+ i
;
313 *((*p
)++) = (MountEntry
) {
314 .path_const
= b
->destination
,
315 .mode
= b
->recursive
? BIND_MOUNT_RECURSIVE
: BIND_MOUNT
,
316 .read_only
= b
->read_only
,
318 .source_const
= b
->source
,
319 .ignore
= b
->ignore_enoent
,
326 static int append_tmpfs_mounts(MountEntry
**p
, const TemporaryFileSystem
*tmpfs
, size_t n
) {
332 for (i
= 0; i
< n
; i
++) {
333 const TemporaryFileSystem
*t
= tmpfs
+ i
;
334 _cleanup_free_
char *o
= NULL
, *str
= NULL
;
338 if (!path_is_absolute(t
->path
))
339 return log_debug_errno(SYNTHETIC_ERRNO(EINVAL
),
340 "Path is not absolute: %s",
343 str
= strjoin("mode=0755,", t
->options
);
347 r
= mount_option_mangle(str
, MS_NODEV
|MS_STRICTATIME
, &flags
, &o
);
349 return log_debug_errno(r
, "Failed to parse mount option '%s': %m", str
);
351 ro
= flags
& MS_RDONLY
;
355 *((*p
)++) = (MountEntry
) {
356 .path_const
= t
->path
,
359 .options_malloc
= TAKE_PTR(o
),
367 static int append_static_mounts(MountEntry
**p
, const MountEntry
*mounts
, size_t n
, bool ignore_protect
) {
373 /* Adds a list of static pre-defined entries */
375 for (i
= 0; i
< n
; i
++)
376 *((*p
)++) = (MountEntry
) {
377 .path_const
= mount_entry_path(mounts
+i
),
378 .mode
= mounts
[i
].mode
,
379 .ignore
= mounts
[i
].ignore
|| ignore_protect
,
385 static int append_protect_home(MountEntry
**p
, ProtectHome protect_home
, bool ignore_protect
) {
388 switch (protect_home
) {
390 case PROTECT_HOME_NO
:
393 case PROTECT_HOME_READ_ONLY
:
394 return append_static_mounts(p
, protect_home_read_only_table
, ELEMENTSOF(protect_home_read_only_table
), ignore_protect
);
396 case PROTECT_HOME_TMPFS
:
397 return append_static_mounts(p
, protect_home_tmpfs_table
, ELEMENTSOF(protect_home_tmpfs_table
), ignore_protect
);
399 case PROTECT_HOME_YES
:
400 return append_static_mounts(p
, protect_home_yes_table
, ELEMENTSOF(protect_home_yes_table
), ignore_protect
);
403 assert_not_reached("Unexpected ProtectHome= value");
407 static int append_protect_system(MountEntry
**p
, ProtectSystem protect_system
, bool ignore_protect
) {
410 switch (protect_system
) {
412 case PROTECT_SYSTEM_NO
:
415 case PROTECT_SYSTEM_STRICT
:
416 return append_static_mounts(p
, protect_system_strict_table
, ELEMENTSOF(protect_system_strict_table
), ignore_protect
);
418 case PROTECT_SYSTEM_YES
:
419 return append_static_mounts(p
, protect_system_yes_table
, ELEMENTSOF(protect_system_yes_table
), ignore_protect
);
421 case PROTECT_SYSTEM_FULL
:
422 return append_static_mounts(p
, protect_system_full_table
, ELEMENTSOF(protect_system_full_table
), ignore_protect
);
425 assert_not_reached("Unexpected ProtectSystem= value");
429 static int mount_path_compare(const MountEntry
*a
, const MountEntry
*b
) {
432 /* If the paths are not equal, then order prefixes first */
433 d
= path_compare(mount_entry_path(a
), mount_entry_path(b
));
437 /* If the paths are equal, check the mode */
438 return CMP((int) a
->mode
, (int) b
->mode
);
441 static int prefix_where_needed(MountEntry
*m
, size_t n
, const char *root_directory
) {
444 /* Prefixes all paths in the bind mount table with the root directory if the entry needs that. */
446 for (i
= 0; i
< n
; i
++) {
452 s
= path_join(root_directory
, mount_entry_path(m
+i
));
456 free_and_replace(m
[i
].path_malloc
, s
);
457 m
[i
].has_prefix
= true;
463 static void drop_duplicates(MountEntry
*m
, size_t *n
) {
464 MountEntry
*f
, *t
, *previous
;
469 /* Drops duplicate entries. Expects that the array is properly ordered already. */
471 for (f
= m
, t
= m
, previous
= NULL
; f
< m
+ *n
; f
++) {
473 /* The first one wins (which is the one with the more restrictive mode), see mount_path_compare()
474 * above. Note that we only drop duplicates that haven't been mounted yet. */
476 path_equal(mount_entry_path(f
), mount_entry_path(previous
)) &&
477 !f
->applied
&& !previous
->applied
) {
478 log_debug("%s (%s) is duplicate.", mount_entry_path(f
), mount_mode_to_string(f
->mode
));
479 previous
->read_only
= previous
->read_only
|| mount_entry_read_only(f
); /* Propagate the read-only flag to the remaining entry */
492 static void drop_inaccessible(MountEntry
*m
, size_t *n
) {
494 const char *clear
= NULL
;
499 /* Drops all entries obstructed by another entry further up the tree. Expects that the array is properly
500 * ordered already. */
502 for (f
= m
, t
= m
; f
< m
+ *n
; f
++) {
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. */
506 if (clear
&& path_startswith(mount_entry_path(f
), clear
)) {
507 log_debug("%s is masked by %s.", mount_entry_path(f
), clear
);
512 clear
= f
->mode
== INACCESSIBLE
? mount_entry_path(f
) : NULL
;
521 static void drop_nop(MountEntry
*m
, size_t *n
) {
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. */
530 for (f
= m
, t
= m
; f
< m
+ *n
; f
++) {
532 /* Only suppress such subtrees for READONLY, READWRITE and READWRITE_IMPLICIT entries */
533 if (IN_SET(f
->mode
, READONLY
, READWRITE
, READWRITE_IMPLICIT
)) {
537 /* Now let's find the first parent of the entry we are looking at. */
538 for (p
= t
-1; p
>= m
; p
--) {
539 if (path_startswith(mount_entry_path(f
), mount_entry_path(p
))) {
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
) {
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
));
562 static void drop_outside_root(const char *root_directory
, MountEntry
*m
, size_t *n
) {
572 /* Drops all mounts that are outside of the root directory. */
574 for (f
= m
, t
= m
; f
< m
+ *n
; f
++) {
576 if (!path_startswith(mount_entry_path(f
), root_directory
)) {
577 log_debug("%s is outside of root directory.", mount_entry_path(f
));
589 static int clone_device_node(
591 const char *temporary_mount
,
592 bool *make_devnode
) {
594 _cleanup_free_
char *sl
= NULL
;
595 const char *dn
, *bn
, *t
;
599 if (stat(d
, &st
) < 0) {
600 if (errno
== ENOENT
) {
601 log_debug_errno(errno
, "Device node '%s' to clone does not exist, ignoring.", d
);
605 return log_debug_errno(errno
, "Failed to stat() device node '%s' to clone, ignoring: %m", d
);
608 if (!S_ISBLK(st
.st_mode
) &&
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.",
614 dn
= strjoina(temporary_mount
, d
);
616 /* First, try to create device node properly */
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();
624 return log_debug_errno(errno
, "mknod failed for %s: %m", d
);
626 /* This didn't work, let's not try this again for the next iterations. */
627 *make_devnode
= false;
630 /* We're about to fallback to bind-mounting the device
631 * node. So create a dummy bind-mount target. */
632 mac_selinux_create_file_prepare(d
, 0);
633 r
= mknod(dn
, S_IFREG
, 0);
634 mac_selinux_create_file_clear();
635 if (r
< 0 && errno
!= EEXIST
)
636 return log_debug_errno(errno
, "mknod() fallback failed for '%s': %m", d
);
638 /* Fallback to bind-mounting:
639 * The assumption here is that all used device nodes carry standard
640 * properties. Specifically, the devices nodes we bind-mount should
641 * either be owned by root:root or root:tty (e.g. /dev/tty, /dev/ptmx)
642 * and should not carry ACLs. */
643 if (mount(d
, dn
, NULL
, MS_BIND
, NULL
) < 0)
644 return log_debug_errno(errno
, "Bind mounting failed for '%s': %m", d
);
647 bn
= path_startswith(d
, "/dev/");
651 /* Create symlinks like /dev/char/1:9 → ../urandom */
652 if (asprintf(&sl
, "%s/dev/%s/%u:%u", temporary_mount
, S_ISCHR(st
.st_mode
) ? "char" : "block", major(st
.st_rdev
), minor(st
.st_rdev
)) < 0)
655 (void) mkdir_parents(sl
, 0755);
657 t
= strjoina("../", bn
);
659 if (symlink(t
, sl
) < 0)
660 log_debug_errno(errno
, "Failed to symlink '%s' to '%s', ignoring: %m", t
, sl
);
665 static int mount_private_dev(MountEntry
*m
) {
666 static const char devnodes
[] =
674 char temporary_mount
[] = "/tmp/namespace-dev-XXXXXX";
675 const char *d
, *dev
= NULL
, *devpts
= NULL
, *devshm
= NULL
, *devhugepages
= NULL
, *devmqueue
= NULL
, *devlog
= NULL
, *devptmx
= NULL
;
676 bool can_mknod
= true;
677 _cleanup_umask_ mode_t u
;
684 if (!mkdtemp(temporary_mount
))
685 return log_debug_errno(errno
, "Failed to create temporary directory '%s': %m", temporary_mount
);
687 dev
= strjoina(temporary_mount
, "/dev");
688 (void) mkdir(dev
, 0755);
689 if (mount("tmpfs", dev
, "tmpfs", DEV_MOUNT_OPTIONS
, "mode=755") < 0) {
690 r
= log_debug_errno(errno
, "Failed to mount tmpfs on '%s': %m", dev
);
694 devpts
= strjoina(temporary_mount
, "/dev/pts");
695 (void) mkdir(devpts
, 0755);
696 if (mount("/dev/pts", devpts
, NULL
, MS_BIND
, NULL
) < 0) {
697 r
= log_debug_errno(errno
, "Failed to bind mount /dev/pts on '%s': %m", devpts
);
701 /* /dev/ptmx can either be a device node or a symlink to /dev/pts/ptmx.
702 * When /dev/ptmx a device node, /dev/pts/ptmx has 000 permissions making it inaccessible.
703 * Thus, in that case make a clone.
704 * In nspawn and other containers it will be a symlink, in that case make it a symlink. */
705 r
= is_symlink("/dev/ptmx");
707 log_debug_errno(r
, "Failed to detect whether /dev/ptmx is a symlink or not: %m");
710 devptmx
= strjoina(temporary_mount
, "/dev/ptmx");
711 if (symlink("pts/ptmx", devptmx
) < 0) {
712 r
= log_debug_errno(errno
, "Failed to create a symlink '%s' to pts/ptmx: %m", devptmx
);
716 r
= clone_device_node("/dev/ptmx", temporary_mount
, &can_mknod
);
721 devshm
= strjoina(temporary_mount
, "/dev/shm");
722 (void) mkdir(devshm
, 0755);
723 r
= mount("/dev/shm", devshm
, NULL
, MS_BIND
, NULL
);
725 r
= log_debug_errno(errno
, "Failed to bind mount /dev/shm on '%s': %m", devshm
);
729 devmqueue
= strjoina(temporary_mount
, "/dev/mqueue");
730 (void) mkdir(devmqueue
, 0755);
731 if (mount("/dev/mqueue", devmqueue
, NULL
, MS_BIND
, NULL
) < 0)
732 log_debug_errno(errno
, "Failed to bind mount /dev/mqueue on '%s', ignoring: %m", devmqueue
);
734 devhugepages
= strjoina(temporary_mount
, "/dev/hugepages");
735 (void) mkdir(devhugepages
, 0755);
736 if (mount("/dev/hugepages", devhugepages
, NULL
, MS_BIND
, NULL
) < 0)
737 log_debug_errno(errno
, "Failed to bind mount /dev/hugepages on '%s', ignoring: %m", devhugepages
);
739 devlog
= strjoina(temporary_mount
, "/dev/log");
740 if (symlink("/run/systemd/journal/dev-log", devlog
) < 0)
741 log_debug_errno(errno
, "Failed to create a symlink '%s' to /run/systemd/journal/dev-log, ignoring: %m", devlog
);
743 NULSTR_FOREACH(d
, devnodes
) {
744 r
= clone_device_node(d
, temporary_mount
, &can_mknod
);
745 /* ENXIO means the the *source* is not a device file, skip creation in that case */
746 if (r
< 0 && r
!= -ENXIO
)
750 r
= dev_setup(temporary_mount
, UID_INVALID
, GID_INVALID
);
752 log_debug_errno(r
, "Failed to setup basic device tree at '%s', ignoring: %m", temporary_mount
);
754 /* Create the /dev directory if missing. It is more likely to be
755 * missing when the service is started with RootDirectory. This is
756 * consistent with mount units creating the mount points when missing.
758 (void) mkdir_p_label(mount_entry_path(m
), 0755);
760 /* Unmount everything in old /dev */
761 r
= umount_recursive(mount_entry_path(m
), 0);
763 log_debug_errno(r
, "Failed to unmount directories below '%s', ignoring: %m", mount_entry_path(m
));
765 if (mount(dev
, mount_entry_path(m
), NULL
, MS_MOVE
, NULL
) < 0) {
766 r
= log_debug_errno(errno
, "Failed to move mount point '%s' to '%s': %m", dev
, mount_entry_path(m
));
771 (void) rmdir(temporary_mount
);
777 (void) umount(devpts
);
780 (void) umount(devshm
);
783 (void) umount(devhugepages
);
786 (void) umount(devmqueue
);
790 (void) rmdir(temporary_mount
);
795 static int mount_bind_dev(const MountEntry
*m
) {
800 /* Implements the little brother of mount_private_dev(): simply bind mounts the host's /dev into the service's
801 * /dev. This is only used when RootDirectory= is set. */
803 (void) mkdir_p_label(mount_entry_path(m
), 0755);
805 r
= path_is_mount_point(mount_entry_path(m
), NULL
, 0);
807 return log_debug_errno(r
, "Unable to determine whether /dev is already mounted: %m");
808 if (r
> 0) /* make this a NOP if /dev is already a mount point */
811 if (mount("/dev", mount_entry_path(m
), NULL
, MS_BIND
|MS_REC
, NULL
) < 0)
812 return log_debug_errno(errno
, "Failed to bind mount %s: %m", mount_entry_path(m
));
817 static int mount_sysfs(const MountEntry
*m
) {
822 (void) mkdir_p_label(mount_entry_path(m
), 0755);
824 r
= path_is_mount_point(mount_entry_path(m
), NULL
, 0);
826 return log_debug_errno(r
, "Unable to determine whether /sys is already mounted: %m");
827 if (r
> 0) /* make this a NOP if /sys is already a mount point */
830 /* Bind mount the host's version so that we get all child mounts of it, too. */
831 if (mount("/sys", mount_entry_path(m
), NULL
, MS_BIND
|MS_REC
, NULL
) < 0)
832 return log_debug_errno(errno
, "Failed to mount %s: %m", mount_entry_path(m
));
837 static int mount_procfs(const MountEntry
*m
) {
842 (void) mkdir_p_label(mount_entry_path(m
), 0755);
844 r
= path_is_mount_point(mount_entry_path(m
), NULL
, 0);
846 return log_debug_errno(r
, "Unable to determine whether /proc is already mounted: %m");
847 if (r
> 0) /* make this a NOP if /proc is already a mount point */
850 /* Mount a new instance, so that we get the one that matches our user namespace, if we are running in one */
851 if (mount("proc", mount_entry_path(m
), "proc", MS_NOSUID
|MS_NOEXEC
|MS_NODEV
, NULL
) < 0)
852 return log_debug_errno(errno
, "Failed to mount %s: %m", mount_entry_path(m
));
857 static int mount_tmpfs(const MountEntry
*m
) {
860 /* First, get rid of everything that is below if there is anything. Then, overmount with our new tmpfs */
862 (void) mkdir_p_label(mount_entry_path(m
), 0755);
863 (void) umount_recursive(mount_entry_path(m
), 0);
865 if (mount("tmpfs", mount_entry_path(m
), "tmpfs", m
->flags
, mount_entry_options(m
)) < 0)
866 return log_debug_errno(errno
, "Failed to mount %s: %m", mount_entry_path(m
));
871 static int follow_symlink(
872 const char *root_directory
,
875 _cleanup_free_
char *target
= NULL
;
878 /* Let's chase symlinks, but only one step at a time. That's because depending where the symlink points we
879 * might need to change the order in which we mount stuff. Hence: let's normalize piecemeal, and do one step at
880 * a time by specifying CHASE_STEP. This function returns 0 if we resolved one step, and > 0 if we reached the
881 * end and already have a fully normalized name. */
883 r
= chase_symlinks(mount_entry_path(m
), root_directory
, CHASE_STEP
|CHASE_NONEXISTENT
, &target
, NULL
);
885 return log_debug_errno(r
, "Failed to chase symlinks '%s': %m", mount_entry_path(m
));
886 if (r
> 0) /* Reached the end, nothing more to resolve */
889 if (m
->n_followed
>= CHASE_SYMLINKS_MAX
) /* put a boundary on things */
890 return log_debug_errno(SYNTHETIC_ERRNO(ELOOP
),
891 "Symlink loop on '%s'.",
892 mount_entry_path(m
));
894 log_debug("Followed mount entry path symlink %s → %s.", mount_entry_path(m
), target
);
896 free_and_replace(m
->path_malloc
, target
);
897 m
->has_prefix
= true;
904 static int apply_mount(
905 const char *root_directory
,
908 bool rbind
= true, make
= false;
914 log_debug("Applying namespace mount on %s", mount_entry_path(m
));
921 /* First, get rid of everything that is below if there
922 * is anything... Then, overmount it with an
923 * inaccessible path. */
924 (void) umount_recursive(mount_entry_path(m
), 0);
926 if (lstat(mount_entry_path(m
), &target
) < 0) {
927 if (errno
== ENOENT
&& m
->ignore
)
930 return log_debug_errno(errno
, "Failed to lstat() %s to determine what to mount over it: %m", mount_entry_path(m
));
933 what
= mode_to_inaccessible_node(target
.st_mode
);
935 return log_debug_errno(SYNTHETIC_ERRNO(ELOOP
),
936 "File type not supported for inaccessible mounts. Note that symlinks are not allowed");
942 case READWRITE_IMPLICIT
:
943 r
= path_is_mount_point(mount_entry_path(m
), root_directory
, 0);
944 if (r
== -ENOENT
&& m
->ignore
)
947 return log_debug_errno(r
, "Failed to determine whether %s is already a mount point: %m", mount_entry_path(m
));
948 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. */
950 /* This isn't a mount point yet, let's make it one. */
951 what
= mount_entry_path(m
);
958 case BIND_MOUNT_RECURSIVE
: {
959 _cleanup_free_
char *chased
= NULL
;
961 /* Since mount() will always follow symlinks we chase the symlinks on our own first. Note that bind
962 * mount source paths are always relative to the host root, hence we pass NULL as root directory to
963 * chase_symlinks() here. */
965 r
= chase_symlinks(mount_entry_source(m
), NULL
, CHASE_TRAIL_SLASH
, &chased
, NULL
);
966 if (r
== -ENOENT
&& m
->ignore
) {
967 log_debug_errno(r
, "Path %s does not exist, ignoring.", mount_entry_source(m
));
971 return log_debug_errno(r
, "Failed to follow symlinks on %s: %m", mount_entry_source(m
));
973 log_debug("Followed source symlinks %s → %s.", mount_entry_source(m
), chased
);
975 free_and_replace(m
->source_malloc
, chased
);
977 what
= mount_entry_source(m
);
984 return mount_tmpfs(m
);
987 what
= mount_entry_source(m
);
992 return mount_private_dev(m
);
995 return mount_bind_dev(m
);
998 return mount_sysfs(m
);
1001 return mount_procfs(m
);
1004 assert_not_reached("Unknown mode");
1009 if (mount(what
, mount_entry_path(m
), NULL
, MS_BIND
|(rbind
? MS_REC
: 0), NULL
) < 0) {
1010 bool try_again
= false;
1013 if (r
== -ENOENT
&& make
) {
1016 /* Hmm, either the source or the destination are missing. Let's see if we can create the destination, then try again */
1018 if (stat(what
, &st
) < 0)
1019 log_debug_errno(errno
, "Mount point source '%s' is not accessible: %m", what
);
1023 (void) mkdir_parents(mount_entry_path(m
), 0755);
1025 if (S_ISDIR(st
.st_mode
))
1026 q
= mkdir(mount_entry_path(m
), 0755) < 0 ? -errno
: 0;
1028 q
= touch(mount_entry_path(m
));
1031 log_debug_errno(q
, "Failed to create destination mount point node '%s': %m", mount_entry_path(m
));
1038 if (mount(what
, mount_entry_path(m
), NULL
, MS_BIND
|(rbind
? MS_REC
: 0), NULL
) < 0)
1045 return log_debug_errno(r
, "Failed to mount %s to %s: %m", what
, mount_entry_path(m
));
1048 log_debug("Successfully mounted %s to %s", what
, mount_entry_path(m
));
1052 /* Change per-mount flags on an existing mount */
1053 static int bind_remount_one(const char *path
, unsigned long orig_flags
, unsigned long new_flags
, unsigned long flags_mask
) {
1054 if (mount(NULL
, path
, NULL
, (orig_flags
& ~flags_mask
) | MS_REMOUNT
| MS_BIND
| new_flags
, NULL
) < 0)
1060 static int make_read_only(const MountEntry
*m
, char **blacklist
, FILE *proc_self_mountinfo
) {
1061 unsigned long new_flags
= 0, flags_mask
= 0;
1062 bool submounts
= false;
1066 assert(proc_self_mountinfo
);
1068 if (mount_entry_read_only(m
) || m
->mode
== PRIVATE_DEV
) {
1069 new_flags
|= MS_RDONLY
;
1070 flags_mask
|= MS_RDONLY
;
1074 new_flags
|= MS_NOSUID
;
1075 flags_mask
|= MS_NOSUID
;
1078 if (flags_mask
== 0) /* No Change? */
1081 /* We generally apply these changes recursively, except for /dev, and the cases we know there's
1082 * nothing further down. Set /dev readonly, but not submounts like /dev/shm. Also, we only set the
1083 * per-mount read-only flag. We can't set it on the superblock, if we are inside a user namespace
1084 * and running Linux <= 4.17. */
1086 mount_entry_read_only(m
) &&
1087 !IN_SET(m
->mode
, EMPTY_DIR
, TMPFS
);
1089 r
= bind_remount_recursive_with_mountinfo(mount_entry_path(m
), new_flags
, flags_mask
, blacklist
, proc_self_mountinfo
);
1091 r
= bind_remount_one(mount_entry_path(m
), m
->flags
, new_flags
, flags_mask
);
1093 /* Not that we only turn on the MS_RDONLY flag here, we never turn it off. Something that was marked
1094 * read-only already stays this way. This improves compatibility with container managers, where we
1095 * won't attempt to undo read-only mounts already applied. */
1097 if (r
== -ENOENT
&& m
->ignore
)
1100 return log_debug_errno(r
, "Failed to re-mount '%s'%s: %m", mount_entry_path(m
),
1101 submounts
? " and its submounts" : "");
1105 static bool namespace_info_mount_apivfs(const NamespaceInfo
*ns_info
) {
1109 * ProtectControlGroups= and ProtectKernelTunables= imply MountAPIVFS=,
1110 * since to protect the API VFS mounts, they need to be around in the
1114 return ns_info
->mount_apivfs
||
1115 ns_info
->protect_control_groups
||
1116 ns_info
->protect_kernel_tunables
;
1119 static size_t namespace_calculate_mounts(
1120 const NamespaceInfo
*ns_info
,
1121 char** read_write_paths
,
1122 char** read_only_paths
,
1123 char** inaccessible_paths
,
1124 char** empty_directories
,
1125 size_t n_bind_mounts
,
1126 size_t n_temporary_filesystems
,
1127 const char* tmp_dir
,
1128 const char* var_tmp_dir
,
1129 ProtectHome protect_home
,
1130 ProtectSystem protect_system
) {
1132 size_t protect_home_cnt
;
1133 size_t protect_system_cnt
=
1134 (protect_system
== PROTECT_SYSTEM_STRICT
?
1135 ELEMENTSOF(protect_system_strict_table
) :
1136 ((protect_system
== PROTECT_SYSTEM_FULL
) ?
1137 ELEMENTSOF(protect_system_full_table
) :
1138 ((protect_system
== PROTECT_SYSTEM_YES
) ?
1139 ELEMENTSOF(protect_system_yes_table
) : 0)));
1142 (protect_home
== PROTECT_HOME_YES
?
1143 ELEMENTSOF(protect_home_yes_table
) :
1144 ((protect_home
== PROTECT_HOME_READ_ONLY
) ?
1145 ELEMENTSOF(protect_home_read_only_table
) :
1146 ((protect_home
== PROTECT_HOME_TMPFS
) ?
1147 ELEMENTSOF(protect_home_tmpfs_table
) : 0)));
1149 return !!tmp_dir
+ !!var_tmp_dir
+
1150 strv_length(read_write_paths
) +
1151 strv_length(read_only_paths
) +
1152 strv_length(inaccessible_paths
) +
1153 strv_length(empty_directories
) +
1155 n_temporary_filesystems
+
1156 ns_info
->private_dev
+
1157 (ns_info
->protect_kernel_tunables
? ELEMENTSOF(protect_kernel_tunables_table
) : 0) +
1158 (ns_info
->protect_kernel_modules
? ELEMENTSOF(protect_kernel_modules_table
) : 0) +
1159 (ns_info
->protect_kernel_logs
? ELEMENTSOF(protect_kernel_logs_table
) : 0) +
1160 (ns_info
->protect_control_groups
? 1 : 0) +
1161 protect_home_cnt
+ protect_system_cnt
+
1162 (ns_info
->protect_hostname
? 2 : 0) +
1163 (namespace_info_mount_apivfs(ns_info
) ? ELEMENTSOF(apivfs_table
) : 0);
1166 static void normalize_mounts(const char *root_directory
, MountEntry
*mounts
, size_t *n_mounts
) {
1167 assert(root_directory
);
1169 assert(mounts
|| *n_mounts
== 0);
1171 typesafe_qsort(mounts
, *n_mounts
, mount_path_compare
);
1173 drop_duplicates(mounts
, n_mounts
);
1174 drop_outside_root(root_directory
, mounts
, n_mounts
);
1175 drop_inaccessible(mounts
, n_mounts
);
1176 drop_nop(mounts
, n_mounts
);
1179 int setup_namespace(
1180 const char* root_directory
,
1181 const char* root_image
,
1182 const NamespaceInfo
*ns_info
,
1183 char** read_write_paths
,
1184 char** read_only_paths
,
1185 char** inaccessible_paths
,
1186 char** empty_directories
,
1187 const BindMount
*bind_mounts
,
1188 size_t n_bind_mounts
,
1189 const TemporaryFileSystem
*temporary_filesystems
,
1190 size_t n_temporary_filesystems
,
1191 const char* tmp_dir
,
1192 const char* var_tmp_dir
,
1193 ProtectHome protect_home
,
1194 ProtectSystem protect_system
,
1195 unsigned long mount_flags
,
1196 DissectImageFlags dissect_image_flags
,
1197 char **error_path
) {
1199 _cleanup_(loop_device_unrefp
) LoopDevice
*loop_device
= NULL
;
1200 _cleanup_(decrypted_image_unrefp
) DecryptedImage
*decrypted_image
= NULL
;
1201 _cleanup_(dissected_image_unrefp
) DissectedImage
*dissected_image
= NULL
;
1202 _cleanup_free_
void *root_hash
= NULL
;
1203 MountEntry
*m
= NULL
, *mounts
= NULL
;
1204 size_t n_mounts
, root_hash_size
= 0;
1205 bool require_prefix
= false;
1211 if (mount_flags
== 0)
1212 mount_flags
= MS_SHARED
;
1215 dissect_image_flags
|= DISSECT_IMAGE_REQUIRE_ROOT
;
1217 if (protect_system
== PROTECT_SYSTEM_STRICT
&&
1218 protect_home
!= PROTECT_HOME_NO
&&
1219 strv_isempty(read_write_paths
))
1220 dissect_image_flags
|= DISSECT_IMAGE_READ_ONLY
;
1222 r
= loop_device_make_by_path(root_image
,
1223 dissect_image_flags
& DISSECT_IMAGE_READ_ONLY
? O_RDONLY
: O_RDWR
,
1227 return log_debug_errno(r
, "Failed to create loop device for root image: %m");
1229 r
= root_hash_load(root_image
, &root_hash
, &root_hash_size
);
1231 return log_debug_errno(r
, "Failed to load root hash: %m");
1233 r
= dissect_image(loop_device
->fd
, root_hash
, root_hash_size
, dissect_image_flags
, &dissected_image
);
1235 return log_debug_errno(r
, "Failed to dissect image: %m");
1237 r
= dissected_image_decrypt(dissected_image
, NULL
, root_hash
, root_hash_size
, dissect_image_flags
, &decrypted_image
);
1239 return log_debug_errno(r
, "Failed to decrypt dissected image: %m");
1243 root
= root_directory
;
1245 /* Always create the mount namespace in a temporary directory, instead of operating
1246 * directly in the root. The temporary directory prevents any mounts from being
1247 * potentially obscured my other mounts we already applied.
1248 * We use the same mount point for all images, which is safe, since they all live
1249 * in their own namespaces after all, and hence won't see each other. */
1251 root
= "/run/systemd/unit-root";
1252 (void) mkdir_label(root
, 0700);
1253 require_prefix
= true;
1256 n_mounts
= namespace_calculate_mounts(
1263 n_temporary_filesystems
,
1264 tmp_dir
, var_tmp_dir
,
1265 protect_home
, protect_system
);
1268 m
= mounts
= new0(MountEntry
, n_mounts
);
1272 r
= append_access_mounts(&m
, read_write_paths
, READWRITE
, require_prefix
);
1276 r
= append_access_mounts(&m
, read_only_paths
, READONLY
, require_prefix
);
1280 r
= append_access_mounts(&m
, inaccessible_paths
, INACCESSIBLE
, require_prefix
);
1284 r
= append_empty_dir_mounts(&m
, empty_directories
);
1288 r
= append_bind_mounts(&m
, bind_mounts
, n_bind_mounts
);
1292 r
= append_tmpfs_mounts(&m
, temporary_filesystems
, n_temporary_filesystems
);
1297 *(m
++) = (MountEntry
) {
1298 .path_const
= "/tmp",
1299 .mode
= PRIVATE_TMP
,
1300 .source_const
= tmp_dir
,
1305 *(m
++) = (MountEntry
) {
1306 .path_const
= "/var/tmp",
1307 .mode
= PRIVATE_TMP
,
1308 .source_const
= var_tmp_dir
,
1312 if (ns_info
->private_dev
) {
1313 *(m
++) = (MountEntry
) {
1314 .path_const
= "/dev",
1315 .mode
= PRIVATE_DEV
,
1316 .flags
= DEV_MOUNT_OPTIONS
,
1320 if (ns_info
->protect_kernel_tunables
) {
1321 r
= append_static_mounts(&m
, protect_kernel_tunables_table
, ELEMENTSOF(protect_kernel_tunables_table
), ns_info
->ignore_protect_paths
);
1326 if (ns_info
->protect_kernel_modules
) {
1327 r
= append_static_mounts(&m
, protect_kernel_modules_table
, ELEMENTSOF(protect_kernel_modules_table
), ns_info
->ignore_protect_paths
);
1332 if (ns_info
->protect_kernel_logs
) {
1333 r
= append_static_mounts(&m
, protect_kernel_logs_table
, ELEMENTSOF(protect_kernel_logs_table
), ns_info
->ignore_protect_paths
);
1338 if (ns_info
->protect_control_groups
) {
1339 *(m
++) = (MountEntry
) {
1340 .path_const
= "/sys/fs/cgroup",
1345 r
= append_protect_home(&m
, protect_home
, ns_info
->ignore_protect_paths
);
1349 r
= append_protect_system(&m
, protect_system
, false);
1353 if (namespace_info_mount_apivfs(ns_info
)) {
1354 r
= append_static_mounts(&m
, apivfs_table
, ELEMENTSOF(apivfs_table
), ns_info
->ignore_protect_paths
);
1359 if (ns_info
->protect_hostname
) {
1360 *(m
++) = (MountEntry
) {
1361 .path_const
= "/proc/sys/kernel/hostname",
1364 *(m
++) = (MountEntry
) {
1365 .path_const
= "/proc/sys/kernel/domainname",
1370 assert(mounts
+ n_mounts
== m
);
1372 /* Prepend the root directory where that's necessary */
1373 r
= prefix_where_needed(mounts
, n_mounts
, root
);
1377 normalize_mounts(root
, mounts
, &n_mounts
);
1380 /* All above is just preparation, figuring out what to do. Let's now actually start doing something. */
1382 if (unshare(CLONE_NEWNS
) < 0) {
1383 r
= log_debug_errno(errno
, "Failed to unshare the mount namespace: %m");
1384 if (IN_SET(r
, -EACCES
, -EPERM
, -EOPNOTSUPP
, -ENOSYS
))
1385 /* If the kernel doesn't support namespaces, or when there's a MAC or seccomp filter in place
1386 * that doesn't allow us to create namespaces (or a missing cap), then propagate a recognizable
1387 * error back, which the caller can use to detect this case (and only this) and optionally
1388 * continue without namespacing applied. */
1394 /* Remount / as SLAVE so that nothing now mounted in the namespace
1395 * shows up in the parent */
1396 if (mount(NULL
, "/", NULL
, MS_SLAVE
|MS_REC
, NULL
) < 0) {
1397 r
= log_debug_errno(errno
, "Failed to remount '/' as SLAVE: %m");
1402 /* A root image is specified, mount it to the right place */
1403 r
= dissected_image_mount(dissected_image
, root
, UID_INVALID
, dissect_image_flags
);
1405 log_debug_errno(r
, "Failed to mount root image: %m");
1409 if (decrypted_image
) {
1410 r
= decrypted_image_relinquish(decrypted_image
);
1412 log_debug_errno(r
, "Failed to relinquish decrypted image: %m");
1417 loop_device_relinquish(loop_device
);
1419 } else if (root_directory
) {
1421 /* A root directory is specified. Turn its directory into bind mount, if it isn't one yet. */
1422 r
= path_is_mount_point(root
, NULL
, AT_SYMLINK_FOLLOW
);
1424 log_debug_errno(r
, "Failed to detect that %s is a mount point or not: %m", root
);
1428 if (mount(root
, root
, NULL
, MS_BIND
|MS_REC
, NULL
) < 0) {
1429 r
= log_debug_errno(errno
, "Failed to bind mount '%s': %m", root
);
1436 /* Let's mount the main root directory to the root directory to use */
1437 if (mount("/", root
, NULL
, MS_BIND
|MS_REC
, NULL
) < 0) {
1438 r
= log_debug_errno(errno
, "Failed to bind mount '/' on '%s': %m", root
);
1443 /* Try to set up the new root directory before mounting anything else there. */
1444 if (root_image
|| root_directory
)
1445 (void) base_filesystem_create(root
, UID_INVALID
, GID_INVALID
);
1448 _cleanup_fclose_
FILE *proc_self_mountinfo
= NULL
;
1449 _cleanup_free_
char **blacklist
= NULL
;
1452 /* Open /proc/self/mountinfo now as it may become unavailable if we mount anything on top of /proc.
1453 * For example, this is the case with the option: 'InaccessiblePaths=/proc' */
1454 proc_self_mountinfo
= fopen("/proc/self/mountinfo", "re");
1455 if (!proc_self_mountinfo
) {
1456 r
= log_debug_errno(errno
, "Failed to open /proc/self/mountinfo: %m");
1458 *error_path
= strdup("/proc/self/mountinfo");
1462 /* First round, establish all mounts we need */
1466 for (m
= mounts
; m
< mounts
+ n_mounts
; ++m
) {
1471 r
= follow_symlink(root
, m
);
1473 if (error_path
&& mount_entry_path(m
))
1474 *error_path
= strdup(mount_entry_path(m
));
1478 /* We hit a symlinked mount point. The entry got rewritten and might point to a
1479 * very different place now. Let's normalize the changed list, and start from
1480 * the beginning. After all to mount the entry at the new location we might
1481 * need some other mounts first */
1486 r
= apply_mount(root
, m
);
1488 if (error_path
&& mount_entry_path(m
))
1489 *error_path
= strdup(mount_entry_path(m
));
1499 normalize_mounts(root
, mounts
, &n_mounts
);
1502 /* Create a blacklist we can pass to bind_mount_recursive() */
1503 blacklist
= new(char*, n_mounts
+1);
1508 for (j
= 0; j
< n_mounts
; j
++)
1509 blacklist
[j
] = (char*) mount_entry_path(mounts
+j
);
1510 blacklist
[j
] = NULL
;
1512 /* Second round, flip the ro bits if necessary. */
1513 for (m
= mounts
; m
< mounts
+ n_mounts
; ++m
) {
1514 r
= make_read_only(m
, blacklist
, proc_self_mountinfo
);
1516 if (error_path
&& mount_entry_path(m
))
1517 *error_path
= strdup(mount_entry_path(m
));
1523 /* MS_MOVE does not work on MS_SHARED so the remount MS_SHARED will be done later */
1524 r
= mount_move_root(root
);
1526 log_debug_errno(r
, "Failed to mount root with MS_MOVE: %m");
1530 /* Remount / as the desired mode. Note that this will not
1531 * reestablish propagation from our side to the host, since
1532 * what's disconnected is disconnected. */
1533 if (mount(NULL
, "/", NULL
, mount_flags
| MS_REC
, NULL
) < 0) {
1534 r
= log_debug_errno(errno
, "Failed to remount '/' with desired mount flags: %m");
1541 for (m
= mounts
; m
< mounts
+ n_mounts
; m
++)
1542 mount_entry_done(m
);
1549 void bind_mount_free_many(BindMount
*b
, size_t n
) {
1552 assert(b
|| n
== 0);
1554 for (i
= 0; i
< n
; i
++) {
1556 free(b
[i
].destination
);
1562 int bind_mount_add(BindMount
**b
, size_t *n
, const BindMount
*item
) {
1563 _cleanup_free_
char *s
= NULL
, *d
= NULL
;
1570 s
= strdup(item
->source
);
1574 d
= strdup(item
->destination
);
1578 c
= reallocarray(*b
, *n
+ 1, sizeof(BindMount
));
1584 c
[(*n
) ++] = (BindMount
) {
1585 .source
= TAKE_PTR(s
),
1586 .destination
= TAKE_PTR(d
),
1587 .read_only
= item
->read_only
,
1588 .nosuid
= item
->nosuid
,
1589 .recursive
= item
->recursive
,
1590 .ignore_enoent
= item
->ignore_enoent
,
1596 void temporary_filesystem_free_many(TemporaryFileSystem
*t
, size_t n
) {
1599 assert(t
|| n
== 0);
1601 for (i
= 0; i
< n
; i
++) {
1609 int temporary_filesystem_add(
1610 TemporaryFileSystem
**t
,
1613 const char *options
) {
1615 _cleanup_free_
char *p
= NULL
, *o
= NULL
;
1616 TemporaryFileSystem
*c
;
1626 if (!isempty(options
)) {
1627 o
= strdup(options
);
1632 c
= reallocarray(*t
, *n
+ 1, sizeof(TemporaryFileSystem
));
1638 c
[(*n
) ++] = (TemporaryFileSystem
) {
1639 .path
= TAKE_PTR(p
),
1640 .options
= TAKE_PTR(o
),
1646 static int make_tmp_prefix(const char *prefix
) {
1647 _cleanup_free_
char *t
= NULL
;
1650 /* Don't do anything unless we know the dir is actually missing */
1651 r
= access(prefix
, F_OK
);
1654 if (errno
!= ENOENT
)
1657 r
= mkdir_parents(prefix
, 0755);
1661 r
= tempfn_random(prefix
, NULL
, &t
);
1665 if (mkdir(t
, 0777) < 0)
1668 if (chmod(t
, 01777) < 0) {
1674 if (rename(t
, prefix
) < 0) {
1677 return r
== -EEXIST
? 0 : r
; /* it's fine if someone else created the dir by now */
1684 static int setup_one_tmp_dir(const char *id
, const char *prefix
, char **path
) {
1685 _cleanup_free_
char *x
= NULL
;
1686 char bid
[SD_ID128_STRING_MAX
];
1694 /* We include the boot id in the directory so that after a
1695 * reboot we can easily identify obsolete directories. */
1697 r
= sd_id128_get_boot(&boot_id
);
1701 x
= strjoin(prefix
, "/systemd-private-", sd_id128_to_string(boot_id
, bid
), "-", id
, "-XXXXXX");
1705 r
= make_tmp_prefix(prefix
);
1709 RUN_WITH_UMASK(0077)
1713 RUN_WITH_UMASK(0000) {
1716 y
= strjoina(x
, "/tmp");
1718 if (mkdir(y
, 0777 | S_ISVTX
) < 0)
1722 *path
= TAKE_PTR(x
);
1727 int setup_tmp_dirs(const char *id
, char **tmp_dir
, char **var_tmp_dir
) {
1733 assert(var_tmp_dir
);
1735 r
= setup_one_tmp_dir(id
, "/tmp", &a
);
1739 r
= setup_one_tmp_dir(id
, "/var/tmp", &b
);
1743 t
= strjoina(a
, "/tmp");
1757 int setup_netns(const int netns_storage_socket
[static 2]) {
1758 _cleanup_close_
int netns
= -1;
1761 assert(netns_storage_socket
);
1762 assert(netns_storage_socket
[0] >= 0);
1763 assert(netns_storage_socket
[1] >= 0);
1765 /* We use the passed socketpair as a storage buffer for our
1766 * namespace reference fd. Whatever process runs this first
1767 * shall create a new namespace, all others should just join
1768 * it. To serialize that we use a file lock on the socket
1771 * It's a bit crazy, but hey, works great! */
1773 if (lockf(netns_storage_socket
[0], F_LOCK
, 0) < 0)
1776 netns
= receive_one_fd(netns_storage_socket
[0], MSG_DONTWAIT
);
1777 if (netns
== -EAGAIN
) {
1778 /* Nothing stored yet, so let's create a new namespace. */
1780 if (unshare(CLONE_NEWNET
) < 0) {
1785 (void) loopback_setup();
1787 netns
= open("/proc/self/ns/net", O_RDONLY
|O_CLOEXEC
|O_NOCTTY
);
1795 } else if (netns
< 0) {
1800 /* Yay, found something, so let's join the namespace */
1801 if (setns(netns
, CLONE_NEWNET
) < 0) {
1809 q
= send_one_fd(netns_storage_socket
[1], netns
, MSG_DONTWAIT
);
1816 (void) lockf(netns_storage_socket
[0], F_ULOCK
, 0);
1820 int open_netns_path(const int netns_storage_socket
[static 2], const char *path
) {
1821 _cleanup_close_
int netns
= -1;
1824 assert(netns_storage_socket
);
1825 assert(netns_storage_socket
[0] >= 0);
1826 assert(netns_storage_socket
[1] >= 0);
1829 /* If the storage socket doesn't contain a netns fd yet, open one via the file system and store it in
1830 * it. This is supposed to be called ahead of time, i.e. before setup_netns() which will allocate a
1831 * new anonymous netns if needed. */
1833 if (lockf(netns_storage_socket
[0], F_LOCK
, 0) < 0)
1836 netns
= receive_one_fd(netns_storage_socket
[0], MSG_DONTWAIT
);
1837 if (netns
== -EAGAIN
) {
1838 /* Nothing stored yet. Open the file from the file system. */
1840 netns
= open(path
, O_RDONLY
|O_NOCTTY
|O_CLOEXEC
);
1846 r
= fd_is_network_ns(netns
);
1847 if (r
== 0) { /* Not a netns? Refuse early. */
1851 if (r
< 0 && r
!= -EUCLEAN
) /* EUCLEAN: we don't know */
1856 } else if (netns
< 0) {
1860 r
= 0; /* Already allocated */
1862 q
= send_one_fd(netns_storage_socket
[1], netns
, MSG_DONTWAIT
);
1869 (void) lockf(netns_storage_socket
[0], F_ULOCK
, 0);
1873 bool ns_type_supported(NamespaceType type
) {
1874 const char *t
, *ns_proc
;
1876 t
= namespace_type_to_string(type
);
1877 if (!t
) /* Don't know how to translate this? Then it's not supported */
1880 ns_proc
= strjoina("/proc/self/ns/", t
);
1881 return access(ns_proc
, F_OK
) == 0;
1884 static const char *const protect_home_table
[_PROTECT_HOME_MAX
] = {
1885 [PROTECT_HOME_NO
] = "no",
1886 [PROTECT_HOME_YES
] = "yes",
1887 [PROTECT_HOME_READ_ONLY
] = "read-only",
1888 [PROTECT_HOME_TMPFS
] = "tmpfs",
1891 DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(protect_home
, ProtectHome
, PROTECT_HOME_YES
);
1893 static const char *const protect_system_table
[_PROTECT_SYSTEM_MAX
] = {
1894 [PROTECT_SYSTEM_NO
] = "no",
1895 [PROTECT_SYSTEM_YES
] = "yes",
1896 [PROTECT_SYSTEM_FULL
] = "full",
1897 [PROTECT_SYSTEM_STRICT
] = "strict",
1900 DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(protect_system
, ProtectSystem
, PROTECT_SYSTEM_YES
);
1902 static const char* const namespace_type_table
[] = {
1903 [NAMESPACE_MOUNT
] = "mnt",
1904 [NAMESPACE_CGROUP
] = "cgroup",
1905 [NAMESPACE_UTS
] = "uts",
1906 [NAMESPACE_IPC
] = "ipc",
1907 [NAMESPACE_USER
] = "user",
1908 [NAMESPACE_PID
] = "pid",
1909 [NAMESPACE_NET
] = "net",
1912 DEFINE_STRING_TABLE_LOOKUP(namespace_type
, NamespaceType
);