Background: Fedora/RHEL are switching to sysusers.d metadata for creation of
users and groups for system users defined by packages
(https://fedoraproject.org/wiki/Changes/RPMSuportForSystemdSysusers).
Packages carry sysusers files. During package installation, rpm calls an
program to execute on this config. This program may either be
/usr/lib/rpm/sysusers.sh which calls useradd/groupadd, or
/usr/bin/systemd-sysusers. To match the functionality provided by
useradd/groupadd from the shadow-utils project, systemd-sysusers must emit
audit events so that it provides a drop-in replacement.
systemd-sysuers will emit audit events AUDIT_ADD_USER/AUDIT_ADD_GROUP when
adding users and groups. The operation "names" are copied from shadow-utils in
Fedora (which has a patch to change them from the upstream version), so the
format of the events that is generated on success should be identical.
The helper code is shared between sysusers and utmp-wtmp. I changed the
audit_fd variable to be unconditional. This way we can avoid ugly iffdefery
every time the variable would be used. The cost is that 4 bytes of unused
storage might be present. This is negligible, and the compiler might even be
able to optimize that away if it inlines things.
Otherwise, the program exits with failure if the first attempt in run() failed:
```
Dec 18 20:27:37 systemd-update-utmp[254]: Bus n/a: changing state UNSET → OPENING
Dec 18 20:27:37 systemd-update-utmp[254]: sd-bus: starting bus by connecting to /run/systemd/private...
Dec 18 20:27:37 systemd-update-utmp[254]: Bus n/a: changing state OPENING → CLOSED
Dec 18 20:27:37 systemd-update-utmp[254]: Failed to get D-Bus connection: Connection refused
```
Before a339495b1d, update-utmp typically
connects the public DBus socket when disconnected from the private DBus
socket, as dbus service should be active even during PID1 is being reexecuted.
However, after a339495b1d, update-utmp
tries to connect only the private DBus socket, but reexecution of PID1
may be slow, hence all trials may fail when the reexecution is slow.
With this change, now it waits for 100ms to 2000ms, so in total it waits
about 37 seconds in average, previously about 4 seconds.
We might also fail to connect to the private manager bus itself if
the daemon-reexec is still ongoing, so let's handle that as well by
retrying on ECONNREFUSED.
Use FOREACH_ELEMENT where possible. Generated with this command,
and checked manually:
git grep -l 'FOREACH_ARRAY.*ELEMENTSOF' | \
xargs sed -ri 's/FOREACH_ARRAY\((.*), (.*), (ELEMENTSOF.*)\)/FOREACH_ELEMENT(\1, \2)/'
We use usec_t for storing time value, which is 64bit.
However, usleep() takes useconds_t that is (typically?) 32bit.
Also, usleep() may only support the range [0, 1000000].
This introduce usleep_safe() which takes usec_t.
-1 was used everywhere, but -EBADF or -EBADFD started being used in various
places. Let's make things consistent in the new style.
Note that there are two candidates:
EBADF 9 Bad file descriptor
EBADFD 77 File descriptor in bad state
Since we're initializating the fd, we're just assigning a value that means
"no fd yet", so it's just a bad file descriptor, and the first errno fits
better. If instead we had a valid file descriptor that became invalid because
of some operation or state change, the other errno would fit better.
In some places, initialization is dropped if unnecessary.
In various cases, we would say 'return log_warning()' or 'return log_error()'. Those
functions return 0 if no error is passed in. For log_warning or log_error this doesn't
make sense, and we generally want to propagate the error. In the few cases where
the error should be ignored, I think it's better to split it in two, and call 'return 0'
on a separate line.
Update logging a bit: drop logging of the pid, nowadays pid1 and journald
do a very good job of logging that. Always log about failure to open audit
fd, but at DEBUG_LEVEL if not important.
If rescue.target, multi-user.target and graphical.target are all
inactive, get_current_runlevel() is not able to determine current
runlevel, and returns with zero. This zero runlevel value results to
assertion failure in utmp_put_runlevel().
# systemctl stop rescue.target multi-user.target graphical.target
# systemctl start systemd-update-utmp-runlevel.service
systemd[1]: Stopped target Graphical Interface.
systemd[1]: Stopped target Multi-User System.
systemd[1]: Starting Update UTMP about System Runlevel Changes...
systemd-update-utmp[67]: Assertion 'runlevel > 0' failed at src/shared/utmp-wtmp.c:275, function utmp_put_runlevel(). Aborting.
systemd[1]: systemd-update-utmp-runlevel.service: Main process exited, code=dumped, status=6/ABRT
systemd[1]: systemd-update-utmp-runlevel.service: Failed with result 'core-dump'.
systemd[1]: Failed to start Update UTMP about System Runlevel Changes.
Let's just print a warning in this case and skip the utmp update, to
avoid systemd-update-utmp-runlevel.service failures.
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
The advantage is that is the name is mispellt, cpp will warn us.
$ git grep -Ee "conf.set\('(HAVE|ENABLE)_" -l|xargs sed -r -i "s/conf.set\('(HAVE|ENABLE)_/conf.set10('\1_/"
$ git grep -Ee '#ifn?def (HAVE|ENABLE)' -l|xargs sed -r -i 's/#ifdef (HAVE|ENABLE)/#if \1/; s/#ifndef (HAVE|ENABLE)/#if ! \1/;'
$ git grep -Ee 'if.*defined\(HAVE' -l|xargs sed -i -r 's/defined\((HAVE_[A-Z0-9_]*)\)/\1/g'
$ git grep -Ee 'if.*defined\(ENABLE' -l|xargs sed -i -r 's/defined\((ENABLE_[A-Z0-9_]*)\)/\1/g'
+ manual changes to meson.build
squash! build-sys: use #if Y instead of #ifdef Y everywhere
v2:
- fix incorrect setting of HAVE_LIBIDN2
This moves pretty much all uses of getpid() over to getpid_raw(). I
didn't specifically check whether the optimization is worth it for each
replacement, but in order to keep things simple and systematic I
switched over everything at once.
We don't have plural in the name of any other -util files and this
inconsistency trips me up every time I try to type this file name
from memory. "formats-util" is even hard to pronounce.
GLIB has recently started to officially support the gcc cleanup
attribute in its public API, hence let's do the same for our APIs.
With this patch we'll define an xyz_unrefp() call for each public
xyz_unref() call, to make it easy to use inside a
__attribute__((cleanup())) expression. Then, all code is ported over to
make use of this.
The new calls are also documented in the man pages, with examples how to
use them (well, I only added docs where the _unref() call itself already
had docs, and the examples, only cover sd_bus_unrefp() and
sd_event_unrefp()).
This also renames sd_lldp_free() to sd_lldp_unref(), since that's how we
tend to call our destructors these days.
Note that this defines no public macro that wraps gcc's attribute and
makes it easier to use. While I think it's our duty in the library to
make our stuff easy to use, I figure it's not our duty to make gcc's own
features easy to use on its own. Most likely, client code which wants to
make use of this should define its own:
#define _cleanup_(function) __attribute__((cleanup(function)))
Or similar, to make the gcc feature easier to use.
Making this logic public has the benefit that we can remove three header
files whose only purpose was to define these functions internally.
See #2008.
Daan De Meyer
Zbigniew Jędrzejewski-Szmek
Yu Watanabe
Matteo Croce
David Tardon
caoxia2008cxx
Tommi Rantala
Lennart Poettering
Daniel Mack