The MountEntry's added for EMPTY_DIR work very similarly to the TMPFS ones.
In both cases, .has_prefix is false. In fact, .has_prefix is false in
*all* the MountEntry's we add except for the access mounts (READONLY etc).
But EMPTY_DIR stuck out by explicitly setting .has_prefix = false.
Let's remove that.
... when no mount options are passed.
Change the code, to avoid the following failure in the newly added tests:
exec-temporaryfilesystem-rw.service: Executing: /usr/bin/sh -x -c
'[ "$(stat -c %a /var)" == 755 ]'
++ stat -c %a /var
+ '[' 1777 == 755 ']'
Received SIGCHLD from PID 30364 (sh).
Child 30364 (sh) died (code=exited, status=1/FAILURE)
(And I spotted an opportunity to use TAKE_PTR() at the end).
We can't remount the underlying superblocks, if we are inside a user
namespace and running Linux <= 4.17. We can only change the per-mount
flags (MS_REMOUNT | MS_BIND).
This type of mount() call can only change the per-mount flags, so we
don't have to worry about passing the right string options now.
Fixes#9914 ("Since 1beab8b was merged, systemd has been failing to start
systemd-resolved inside unprivileged containers" ... "Failed to re-mount
'/run/systemd/unit-root/dev' read-only: Operation not permitted").
> It's basically my fault :-). I pointed out we could remount read-only
> without MS_BIND when reviewing the PR that added TemporaryFilesystem=,
> and poettering suggested to change PrivateDevices= at the same time.
> I think it's safe to change back, and I don't expect anyone will notice
> a difference in behaviour.
>
> It just surprised me to realize that
> `TemporaryFilesystem=/tmp:size=10M,ro,nosuid` would not apply `ro` to the
> superblock (underlying filesystem), like mount -osize=10M,ro,nosuid does.
> Maybe a comment could note the kernel version (v4.18), that lets you
> remount without MS_BIND inside a user namespace.
This makes the code longer and I guess this function is still ugly, sorry.
One obstacle to cleaning it up is the interaction between
`PrivateDevices=yes` and `ReadOnlyPaths=/dev`. I've added a test for the
existing behaviour, which I think is now the correct behaviour.
This makes two changes to the namespacing code:
1. We'll only gracefully skip service namespacing on access failure if
exclusively sandboxing options where selected, and not mount-related
options that result in a very different view of the world. For example,
ignoring RootDirectory=, RootImage= or Bind= is really probablematic,
but ReadOnlyPaths= is just a weaker sandbox.
2. The namespacing code will now return a clearly recognizable error
code when it cannot enforce its namespacing, so that we cannot
confuse EPERM errors from mount() with those from unshare(). Only the
errors from the first unshare() are now taken as hint to gracefully
disable namespacing.
Fixes: #9844#9835
The fstab entry may contain comment/application-specific options, like
for example x-systemd.automount or x-initrd.mount.
With the recent switch to libmount, the mount options during remount are
now gathered via mnt_fs_get_options(), which returns the merged fstab
options with the effective options in mountinfo.
Unfortunately if one of these application-specific options are set in
fstab, the remount will fail with -EINVAL.
In systemd 238:
Remounting '/test-x-initrd-mount' read-only in with options
'errors=continue,user_xattr,acl'.
In systemd 239:
Remounting '/test-x-initrd-mount' read-only in with options
'errors=continue,user_xattr,acl,x-initrd.mount'.
Failed to remount '/test-x-initrd-mount' read-only: Invalid argument
So instead of using mnt_fs_get_options(), we're now using both
mnt_fs_get_fs_options() and mnt_fs_get_vfs_options() and merging the
results together so we don't get any non-relevant options from fstab.
Signed-off-by: aszlig <aszlig@nix.build>
Let's fold get_user_creds_clean() into get_user_creds(), and introduce a
flags argument for it to select "clean" behaviour. This flags parameter
also learns to other new flags:
- USER_CREDS_SYNTHESIZE_FALLBACK: in this mode the user records for
root/nobody are only synthesized as fallback. Normally, the synthesized
records take precedence over what is in the user database. With this
flag set this is reversed, and the user database takes precedence, and
the synthesized records are only used if they are missing there. This
flag should be set in cases where doing NSS is deemed safe, and where
there's interest in knowing the correct shell, for example if the
admin changed root's shell to zsh or suchlike.
- USER_CREDS_ALLOW_MISSING: if set, and a UID/GID is specified by
numeric value, and there's no user/group record for it accept it
anyway. This allows us to fix#9767
This then also ports all users to set the most appropriate flags.
Fixes: #9767
[zj: remove one isempty() call]
On the host these symlinks are created by udev, and we consider them API
and make use of them ourselves at various places. Hence when running a
private /dev, also create these symlinks so that lookups by major/minor
work in such an environment, too.
When stdin/stdout/stderr is initialized from an fd, let's read the tty
name of it if we can, and pass that to PAM.
This makes sure that "machinectl shell" sessions have proper TTY fields
initialized that "loginctl" then shows.
This is a bit like the info link in most of GNU's --help texts, but we
don't do info but man pages, and we make them properly clickable on
terminal supporting that, because awesome.
I think it's generally advisable to link up our (brief) --help texts and
our (more comprehensive) man pages a bit, so this should be an easy and
straight-forward way to do it.
Previously, we'd act immediately on StopWhenUnneeded= when a unit state
changes. With this rework we'll maintain a queue instead: whenever
there's the chance that StopWhenUneeded= might have an effect we enqueue
the unit, and process it later when we have nothing better to do.
This should make the implementation a bit more reliable, as the unit notify event
cannot immediately enqueue tons of side-effect jobs that might
contradict each other, but we do so only in a strictly ordered fashion,
from the main event loop.
This slightly changes the check when to consider a unit "unneeded".
Previously, we'd assume that a unit in "deactivating" state could also
be cleaned up. With this new logic we'll only consider units unneeded
that are fully up and have no job queued. This means that whenever
there's something pending for a unit we won't clean it up.
Looked for definitions of functions using the *_compare_func() suffix.
Tested:
- Unit tests passed (ninja -C build/ test)
- Installed this build and booted with it.
RootImage= may require the following settings
```
DeviceAllow=/dev/loop-control rw
DeviceAllow=block-loop rwm
DeviceAllow=block-blkext rwm
```
This adds the following settings implicitly when RootImage= is
specified.
Fixes#9737.
These take a struct iovec to send data together with the passed FD.
The receive function returns the FD through an output argument. In case data is
received, but no FD is passed, the receive function will set the output
argument to -1 explicitly.
Update code in dynamic-user to use the new helpers.
When DynamicUser=yes and static User= are set, and the user has
different uid and gid, then as the storage socket for the dynamic
user does not contains gid, we need to obtain gid.
Follow-up for 9ec655cbbd.
Fixes#9702.
Users are often surprised that "systemd-run" command lines like
"systemd-run -p User=idontexist /bin/true" will return successfully,
even though the logs show that the process couldn't be invoked, as the
user "idontexist" doesn't exist. This is because Type=simple will only
wait until fork() succeeded before returning start-up success.
This patch adds a new service type Type=exec, which is very similar to
Type=simple, but waits until the child process completed the execve()
before returning success. It uses a pipe that has O_CLOEXEC set for this
logic, so that the kernel automatically sends POLLHUP on it when the
execve() succeeded but leaves the pipe open if not. This means PID 1
waits exactly until the execve() succeeded in the child, and not longer
and not shorter, which is the desired functionality.
Making use of this new functionality, the command line
"systemd-run -p User=idontexist -p Type=exec /bin/true" will now fail,
as expected.
When process fd lists to pass to activated programs we always place the
socket activation fds first, and the storage fds last. Irritatingly in
almost all calls the "n_storage_fds" parameter (i.e. the number of
storage fds to pass) came first so far, and the "n_socket_fds" parameter
second. Let's clean this up, and specify the number of fds in the order
the fds themselves are passed.
(Also, let's fix one more case where "unsigned" was used to size an
array, while we should use "size_t" instead.)
We so far had various placed we'd parse percentages with
parse_percent(). Let's make them use parse_permille() instead, which is
downward compatible (as it also parses percent values), and increases
the granularity a bit. Given that on the wire we usually normalize
relative specifications to something like UINT32_MAX anyway changing
from base-100 to base-1000 calculations can be done easily without
breaking compat.
This commit doesn't document this change in the man pages. While
allowing more precise specifcations permille is not as commonly
understood as perent I guess, hence let's keep this out of the docs for
now.
Yu Watanabe