Add LockPersonality boolean to allow locking down personality(2)
system call so that the execution domain can't be changed.
This may be useful to improve security because odd emulations
may be poorly tested and source of vulnerabilities, while
system services shouldn't need any weird personalities.
This patch adds two new special character prefixes to ExecStart= and
friends, in addition to the existing "-", "@" and "+":
"!" → much like "+", except with a much reduced effect as it only
disables the actual setresuid()/setresgid()/setgroups() calls, but
leaves all other security features on, including namespace
options. This is very useful in combination with
RuntimeDirectory= or DynamicUser= and similar option, as a user
is still allocated and used for the runtime directory, but the
actual UID/GID dropping is left to the daemon process itself.
This should make RuntimeDirectory= a lot more useful for daemons
which insist on doing their own privilege dropping.
"!!" → Similar to "!", but on systems supporting ambient caps this
becomes a NOP. This makes it relatively straightforward to write
unit files that make use of ambient capabilities to let systemd
drop all privs while retaining compatibility with systems that
lack ambient caps, where priv dropping is the left to the daemon
codes themselves.
This is an alternative approach to #6564 and related PRs.
This new group lists all UID/GID credential changing syscalls (which are
quite a number these days). This will become particularly useful in a
later commit, which uses this group to optionally permit user credential
changing to daemons in case ambient capabilities are not available.
Currently if tmpfiles is run with force on symlink creation but there already
exists a directory at that location, the creation will fail. This change
updates the behavior to remove the directory with rm_fr and then attempts to
create the symlink again.
* Containers don't use serial-getty@console.service,
they use console-getty.service instead, and suppress
scanning for kernel or virtualizer consoles.
* Nowadays gettys are started on *all* configured kernel consoles.
* except for the line printer console, because that's not a tty.
(Seriously. Search CONFIG_LP_CONSOLE).
some run_target() calls were using params from custom_target()
example message:
WARNING: Passed invalid keyword argument "input". This will become a hard error in the future.
New way to call targets:
ninja man/man
ninja man/html
ninja man/update-man-rules
Without this requirement, if proxy-to-nginx.socket was down, and the sysadmin
were to do:
systemctl start proxy-to-nginx.service
then the service would come up without a configured socket, which doesn't make
sense. Normally this isn't how we expect a socket-activated service to start,
but it's possible for an admin to do this (if the .socket were already running,
the systemd-socket-proxyd process will start effectively idle). But the
.service shouldn't end up in a broken state if the .socket isn't already
listening.
Adding the explicit Requires: should ensure that an admin with this
configuration state can't accidentally break their system.
The long man page paragraph got it right: the tool is for escaping systemd unit
names, not just system unit names. Also fix the short man page paragraph
and the --help text.
Follow-up for 303608c1bc
rescue.target does not work well, and we don't have a suitable emergency
shell unit that can be started on existing systems right now. So let's just
remove the recommendation for now.
Fixes#6451.
Since busname units are only useful with kdbus, they weren't actively
used. This was dead code, only compile-tested. If busname units are
ever added back, it'll be cleaner to start from scratch (possibly reverting
parts of this patch).
This introduces {State,Cache,Log,Configuration}Directory= those are
similar to RuntimeDirectory=. They create the directories under
/var/lib, /var/cache/, /var/log, or /etc, respectively, with the mode
specified in {State,Cache,Log,Configuration}DirectoryMode=.
This also fixes#6391.
This has a long history; see see 5261ba9018
which originally introduced the behavior. Unfortunately that commit
doesn't include any rationale, but IIRC the basic issue is that
systemd wants to model the real mount state as units, and symlinks
make canonicalization much more difficult.
At the same time, on a RHEL6 system (upstart), one can make e.g. `/home` a
symlink, and things work as well as they always did; but one doesn't have
access to the sophistication of mount units (dependencies, introspection, etc.)
Supporting symlinks here will hence make it easier for people to do upgrades to
RHEL7 and beyond.
The `/home` as symlink case also appears prominently for OSTree; see
https://ostree.readthedocs.io/en/latest/manual/adapting-existing/
Further work has landed in the nspawn case for this; see e.g.
d944dc9553
A basic limitation with doing this in the fstab generator (and that I hit while
doing some testing) is that we obviously can't chase symlinks into mounts,
since the generator runs early before mounts. Or at least - doing so would
require multiple passes over the fstab data (as well as looking at existing
mount units), and potentially doing multi-phase generation. I'm not sure it's
worth doing that without a real world use case. For now, this will fix at least
the OSTree + `/home` <https://bugzilla.redhat.com/show_bug.cgi?id=1382873> case
mentioned above, and in general anyone who for whatever reason has symlinks in
their `/etc/fstab`.
