This is similar to RootDirectory= but mounts the root file system from a
block device or loopback file instead of another directory.
This reuses the image dissector code now used by nspawn and
gpt-auto-discovery.
This adds two new settings BindPaths= and BindReadOnlyPaths=. They allow
defining arbitrary bind mounts specific to particular services. This is
particularly useful for services with RootDirectory= set as this permits making
specific bits of the host directory available to chrooted services.
The two new settings follow the concepts nspawn already possess in --bind= and
--bind-ro=, as well as the .nspawn settings Bind= and BindReadOnly= (and these
latter options should probably be renamed to BindPaths= and BindReadOnlyPaths=
too).
Fixes: #3439
Lets go further and make /lib/modules/ inaccessible for services that do
not have business with modules, this is a minor improvment but it may
help on setups with custom modules and they are limited... in regard of
kernel auto-load feature.
This change introduce NameSpaceInfo struct which we may embed later
inside ExecContext but for now lets just reduce the argument number to
setup_namespace() and merge ProtectKernelModules feature.
This adds logic to chase symlinks for all mount points that shall be created in
a namespace environment in userspace, instead of leaving this to the kernel.
This has the advantage that we can correctly handle absolute symlinks that
shall be taken relative to a specific root directory. Moreover, we can properly
handle mounts created on symlinked files or directories as we can merge their
mounts as necessary.
(This also drops the "done" flag in the namespace logic, which was never
actually working, but was supposed to permit a partial rollback of the
namespace logic, which however is only mildly useful as it wasn't clear in
which case it would or would not be able to roll back.)
Fixes: #3867
When a service is chrooted with the option RootDirectory=/opt/..., then
the options PrivateDevices, PrivateTmp, ProtectHome, ProtectSystem must
mount the directories under $RootDirectory/{dev,tmp,home,usr,boot}.
The test-ns tool can test setup_namespace() with and without chroot:
$ sudo TEST_NS_PROJECTS=/home/lennart/projects ./test-ns
$ sudo TEST_NS_CHROOT=/home/alban/debian-tree TEST_NS_PROJECTS=/home/alban/debian-tree/home/alban/Documents ./test-ns
This patch removes includes that are not used. The removals were found with
include-what-you-use which checks if any of the symbols from a header is
in use.
If the format string contains %m, clearly errno must have a meaningful
value, so we might as well use log_*_errno to have ERRNO= logged.
Using:
find . -name '*.[ch]' | xargs sed -r -i -e \
's/log_(debug|info|notice|warning|error|emergency)\((".*%m.*")/log_\1_errno(errno, \2/'
Plus some whitespace, linewrap, and indent adjustments.
As a followup to 086891e5c1 "log: add an "error" parameter to all
low-level logging calls and intrdouce log_error_errno() as log calls
that take error numbers", use sed to convert the simple cases to use
the new macros:
find . -name '*.[ch]' | xargs sed -r -i -e \
's/log_(debug|info|notice|warning|error|emergency)\("(.*)%s"(.*), strerror\(-([a-zA-Z_]+)\)\);/log_\1_errno(-\4, "\2%m"\3);/'
Multi-line log_*() invocations are not covered.
And we also should add log_unit_*_errno().
If a path to a previously created custom kdbus endpoint is passed in,
bind-mount a new devtmpfs that contains a 'bus' node, which in turn in
bind-mounted with the custom endpoint. This tmpfs then mounted over the
kdbus subtree that refers to the current bus.
This way, we can fake the bus node in order to lock down services with
a kdbus custom endpoint policy.
Also, rename ProtectedHome= to ProtectHome=, to simplify things a bit.
With this in place we now have two neat options ProtectSystem= and
ProtectHome= for protecting the OS itself (and optionally its
configuration), and for protecting the user's data.
ReadOnlySystem= uses fs namespaces to mount /usr and /boot read-only for
a service.
ProtectedHome= uses fs namespaces to mount /home and /run/user
inaccessible or read-only for a service.
This patch also enables these settings for all our long-running services.
Together they should be good building block for a minimal service
sandbox, removing the ability for services to modify the operating
system or access the user's private data.
Similar to PrivateNetwork=, PrivateTmp= introduce PrivateDevices= that
sets up a private /dev with only the API pseudo-devices like /dev/null,
/dev/zero, /dev/random, but not any physical devices in them.
All Execs within the service, will get mounted the same
/tmp and /var/tmp directories, if service is configured with
PrivateTmp=yes. Temporary directories are cleaned up by service
itself in addition to systemd-tmpfiles. Directory which is mounted
as inaccessible is created at runtime in /run/systemd.
- don't use pivot_root() anymore, just reuse root hierarchy
- first create all mounts, then mark them read-only so that we get the
right behaviour when people want writable mounts inside of
read-only mounts
- don't pass invalid combinations of MS_ constants to the kernel
