Attempt to address
https://github.com/systemd/systemd/issues/20330#issuecomment-1210028422.
Summary of the comment: Unprivileged users can potentially cause a denial of
service during systemd-oomd unit subscriptions by spamming requests to
SubscribeManagedOOMCGroups. As systemd-oomd.service is the only unit that
should be accessing this method, add a check on the caller's unit name to deter
them from successfully using this method.
We can just make this an enum, as long as we ensure it has enough range,
which we can do by adding -ERRNO_MAX as one possible value (at least on
GNU C). We already do that at multiple other places, so let's do this
here too.
We had an anonymous enum with values called UNIT_FILE_…, which could easily be
confused with UNIT_FILE_… from UnitFileFlags enum. This commit renames the enum
values and also the variables which refer to them.
The new function DumpPatterns() can be used to limit (drastically) the size of
the data returned by PID1. Hence the optimization of serializing data into a
file descriptor should be less relevant than having the possibility to limit
the data when communicating with the service manager remotely.
NB: when passing patterns, the dump command omits the version of the manager as
well as the features and the timestamps.
strerror() is not thread safe and calling it just isn't worth the effort
required to justify why it would be safe in those cases. It's easier to just
use %m which is thread-safe out of the box. I don't think that any of the
changes in the patch cause any functional difference. This is just about
getting rid of calls to strerror() in general.
When we print an error message and fail to format the string, using something
like "(null)" is good enough. This is very very unlikely to happen anyway.
- new symbols are available from libbpf 0.6.0 so could be used with
libbpf.so.0, but we're sure the old symbols will be there and this
simplifies code
- detection at runtime should always work, regardless of whether systemd
has been compiled with older or newer libbpf and runs with older or newer
libbpf
UNIT_DEPENDENCY_MOUNTINFO_OR_FILE was a bit strange as unlike the other flags
we don't know where the dependency came from exactly. Indeed its origin could
have been from the mount unit file or from /proc/self/mountinfo.
Instead this patch replaces UNIT_DEPENDENCY_MOUNTINFO_OR_FILE with 2 new
dependency flags: UNIT_DEPENDENCY_MOUNT_FILE and UNIT_DEPENDENCY_MOUNTINFO. The
former indicates that the dep is created from the unit file but unlike
UNIT_DEPENDENCY_FILE, it will be replaced by a dep with the
UNIT_DEPENDENCY_MOUNTINFO flag as soon as the kernel will make the mount
available in /proc/self/mountinfo.
The quota options have always been read from the unit file and ignored if only
present in /proc/self/mountinfo. IOW the quota services are not (automagically)
pulled in for mounts initiated by the user running mount(8).
The very basic functinality of StateDirectory= or friends is creating
specified directories. That should work if one entry is a subdirectory
of another. However, it does not when combined with DynamicUser=yes.
To support such case, this adds ExecDirectoryItem.only_create flag, and
if it is set PID1 only create private directory, and not create the symlink
to the private directory.
Fixes#24783.
The code to evaluate the kernel command line option was busted because it
was doing 'return b == !!r' at a point where 'r > 0'. Thus we'd return "true"
in both cases:
$ SYSTEMD_PROC_CMDLINE=systemd.condition-first-boot build/systemd-analyze condition 'ConditionFirstBoot=true'
test.service: ConditionFirstBoot=true succeeded.
Conditions succeeded.
$ SYSTEMD_PROC_CMDLINE=systemd.condition-first-boot build/systemd-analyze condition 'ConditionFirstBoot=false'
test.service: ConditionFirstBoot=false succeeded.
Conditions succeeded.
We only use 'ConditionFirstBoot=true' in units, so this wasn't noticed.
But I think the logic is broken in general: the condition should evaluate as
true only during initial boot. If we rerun the units at later points, we should
not consider ConditionFirstBoot to be true.
Also, the first boot logic is also used in pid1 itself. AFAICT, for two
things: in first boot machine-id is initialized transiently (this allows
first-boot operations to be restarted if boot fails), and preset-all is
executed. But this logic was different and separate from the logic to
evaluate ConditionFirstBoot. The distinction is abolished, and the operations
in pid1 now use the same logic as ConditionFirstBoot, which means that the
kernel command line option is checked, and condition_test_first_boot()
just tests whether pid1 thinks we're in first boot.
This makes things easier to grok for the user: there's just one condition for
"first boot" and it applies to both pid1 and units.
On socket creation respect the SELinuxContext= setting of the associated
service, such that the initial created socket has the same label as the
future process accepting the connection (since w.r.t SELinux sockets
normally have the same label as the owning process).
Triggered by #24702
In most cases we refernced the concept as "initrd". Let's convert most
remaining uses of "initramfs" to "initrd" too, to stay internally
consistent.
This leaves "initramfs" only where it's relevant to explain historical
concepts or where "initramfs" is part of the API (i.e. in
/run/initramfs).
Follow-up for: b66a6e1a58
Previously, existing device units for devlinks or aliases were not
removed unless the main device unit is removed. This makes all existing
device units for devlinks and aliases are checked if they are still
required, and remove if not necessary anymore.
Fixes#24518.
Systemd's credential interface is not yet natively supported by all
programs yet. Hence it's often required to run scripts to massage
secrets in the way the programs expect it.
This commit allows the ExecStartPre commands to access credentials.
Fixes https://github.com/systemd/systemd/issues/19604
We have free_and_replace() and friends, they are all named with lower
letters, even they are macros, not functions.
For consistency, let's rename CLOSE_AND_REPLACE() with lower letters.
This also mekes the macro used more places.
Follow-up for 10f3f4ed01.
We already have RuntimeWatchdogUSec or friends. Let's not introduce
redundant properties.
Also, drop the const qualifier for WatchdogLastPingTimestamp, as they
are actually not constant.
This renames UidRange -> UidRangeEntry, and reintroduces UidRange which
contains the array of UidRangeEntry and its size.
No fucntional changes, just refactoring.
Thomas Blume
Anita Zhang
Zbigniew Jędrzejewski-Szmek
Lennart Poettering
Franck Bui
Luca Boccassi
Yu Watanabe
Dominique Martinet
Daan De Meyer
Christian Brauner
James Hilliard
Christian Göttsche
Jörg Thalheim
j00512545