Previously, we'd already have explicit logging for the case where
$XDG_RUNTIME_DIR is not set. Let's also add some explicit logging for
the EPERM/ACCESS case. Let's also in both cases suggest the
--machine=<user>@.host syntax.
And while we are at it, let's remove side-effects from the macro.
By checking for both the EPERM/EACCES case and the $XDG_RUNTIME_DIR case
we will now catch both the cases where people use "su" to issue a
"systemctl --user" operation, and those where they (more correctly, but
still not good enough) call "su -".
Fixes: #17901
We would return ENOENT, which is extremely confusing. Strace is not helpful because
no *file* is actually missing. So let's add some logs at debug level and also use
a custom return code. Let all user-facing utilities print a custom error message
in that case.
We return BUS_ERROR_NO_SUCH_UNIT a.k.a. org.freedesktop.systemd1.NoSuchUnit
in various places. In #16813:
Aug 22 06:14:48 core sudo[2769199]: pam_systemd_home(sudo:account): Failed to query user record: Unit dbus-org.freedesktop.home1.service not found.
Aug 22 06:14:48 core dbus-daemon[5311]: [system] Activation via systemd failed for unit 'dbus-org.freedesktop.home1.service': Unit dbus-org.freedesktop.home1.service not found.
Aug 22 06:14:48 core dbus-daemon[5311]: [system] Activating via systemd: service name='org.freedesktop.home1' unit='dbus-org.freedesktop.home1.service' requested by ':1.6564' (uid=0 pid=2769199 comm="sudo su ")
This particular error comes from bus_unit_validate_load_state() in pid1:
case UNIT_NOT_FOUND:
return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_UNIT, "Unit %s not found.", u->id);
It seems possible that we should return a different error, but it doesn't really
matter: if we change pid1 to return a different error, we still need to handle
BUS_ERROR_NO_SUCH_UNIT as in this patch to handle pid1 with current code.
The idea is to have a static table that defines the dbus API. The vtable is
defined right next to the interface name and path because they are logically
connected.
Many of the convenience functions from sd-bus operate on verbose sets
of discrete strings for destination/path/interface/member.
For most callers, destination/path/interface are uniform, and just the
member is distinct.
This commit introduces a new struct encapsulating the
destination/path/interface pointers called BusAddress, and wrapper
functions which take a BusAddress* instead of three strings, and just
pass the encapsulated strings on to the sd-bus convenience functions.
Future commits will update call sites to use these helpers throwing
out a bunch of repetitious destination/path/interface strings littered
throughout the codebase, replacing them with some appropriately named
static structs passed by pointer to these new helpers.
With SYSTEMD_LOG_LOCATION=1, it is much more useful to see the location
where the call to bus_log_{parse,create}_error() was made, rather then
the one-line body of the helper function. Also, it's our internal code,
so having a one-line non-inline function doesn't make much sense anyway.
This augments the drm/input device management by adding a single method
call for setting the brightness of an "leds" or "backlight" kernel class
device.
This method call requires no privileges to call, but a caller can only
change the brightness on sessions that are currently active, and they
must own the session.
This does not do enumeration of such class devices, feature or range
probing, chnage notification; it doesn't help associating graphics or
input devices with their backlight or leds devices. For all that clients
should go directly to udev/sysfs. The SetBrightness() call is just for
executing the actual change operation, that is otherwise privileged.
Example line:
busctl call org.freedesktop.login1 /org/freedesktop/login1/session/self org.freedesktop.login1.Session SetBrightness ssu "backlight" "intel_backlight" 200
The parameter the SetBrightness() call takes are the kernel subsystem
(i.e. "leds" or "backlight"), the device name, and the brightness
value.
On some hw setting the brightness is slow, and implementation and write
access to the sysfs knobs exposes this slowness. Due to this we'll fork
off a writer process in the background so that logind doesn't have to
block. Moreover, write requestes are coalesced: when a write request is
enqueued while one is already being executed it is queued. When another
write reques is then enqueued the earlier one is replaced by the newer
one, so that only one queued write request per device remains at any
time. Method replies are sent as soon as the first write request that
happens after the request was received is completed.
It is recommended that bus clients turn off the "expect_reply" flag on
the dbus messages they send though, that relieves logind from sending
completion notification and is particularly a good idea if clients
implement reactive UI sliders that send a quick secession of write
requests.
Replaces: #12413
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.
Let's always write "1 << 0", "1 << 1" and so on, except where we need
more than 31 flag bits, where we write "UINT64(1) << 0", and so on to force
64bit values.
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.
This adds flags BUS_MAP_STRDUP and BUS_MAP_BOOLEAN_AS_BOOL.
If BUS_MAP_STRDUP is set, then each "s" message is duplicated.
If BUS_MAP_BOOLEAN_AS_BOOL is set, then each "b" message is
written to a bool pointer.
Follow-up for #8488.
See https://github.com/systemd/systemd/pull/8488#discussion_r175816270.
ISO C does not allow empty statements outside of functions, and gcc
will warn the trailing semicolons when compiling with -pedantic:
warning: ISO C does not allow extra ‘;’ outside of a function [-Wpedantic]
But our code cannot compile with -pedantic anyway, at least because
warning: ISO C does not support ‘__PRETTY_FUNCTION__’ predefined identifier [-Wpedantic]
Without -pedatnic, clang and even old gcc (3.4) generate no warnings about
those semicolons, so let's just drop __useless_struct_to_allow_trailing_semicolon__.
The changes both networkd and resolved to make use of the watch_bind
feature of sd-bus to connect to the system bus. This way, both daemons
can be started during early boot, and automatically and instantly
connect to the system bus as it becomes available.
This replaces prior code that used a time-based retry logic to connect
to the bus.
And then show it, to make things a bit friendlier to the user if we fail
acquiring some props.
In fact, this fixes a number of actual bugs, where we used an error
structure for output that we actually never got an error in.
Delete the dbus1 generator and some critical wiring. This prevents
kdbus from being loaded or detected. As such, it will never be used,
even if the user still has a useful kdbus module loaded on their system.
Sort of fixes#3480. Not really, but it's better than the current state.
Previously we'd have generally useful sd-bus utilities in bust-util.h,
intermixed with code that is specifically for writing clients for PID 1,
wrapping job and unit handling. Let's split the latter out and move it into
bus-unit-util.c, to make the sources a bit short and easier to grok.
With this option, systemctl will only print the rhs in show:
$ systemctl show -p Wants,After systemd-journald --value
systemd-journald.socket ...
systemd-journald-dev-log.socket ...
This is useful in scripts, because the need to call awk or similar
is removed.
Lennart Poettering