This macro will read a pointer of any type, return it, and set the
pointer to NULL. This is useful as an explicit concept of passing
ownership of a memory area between pointers.
This takes inspiration from Rust:
https://doc.rust-lang.org/std/option/enum.Option.html#method.take
and was suggested by Alan Jenkins (@sourcejedi).
It drops ~160 lines of code from our codebase, which makes me like it.
Also, I think it clarifies passing of ownership, and thus helps
readability a bit (at least for the initiated who know the new macro)
This is useful so that callers know whether anything at all and how much
was flushed.
This patches through users of this functions to ensure that the return
values > 0 which may be returned now are not propagated in public APIs.
Also, users that ignore the return value are changed to do so explicitly
now.
Observed when running from the console of a systemd nspawn container
(see failure below).
The value of r was tested, when r was last set by
sd_session_can_graphical(). This did not correspond to the value expected.
Fix the code, so we compare relevant values now. Hopefully :).
Test failure
------------
/* Information printed is from the live system */
sd_pid_get_unit(0, …) → "session-13.scope"
sd_pid_get_user_unit(0, …) → "n/a"
sd_pid_get_slice(0, …) → "user-1000.slice"
sd_pid_get_session(0, …) → "13"
sd_pid_get_owner_uid(0, …) → 1000
sd_pid_get_cgroup(0, …) → "/user.slice/user-1000.slice/session-13.scope"
sd_uid_get_display(1000, …) → "13"
sd_uid_get_sessions(1000, …) → [2] "15 13"
sd_uid_get_seats(1000, …) → [1] "seat0"
sd_session_is_active("13") → yes
sd_session_is_remote("13") → no
sd_session_get_state("13") → "active"
sd_session_get_uid("13") → 1000
sd_session_get_type("13") → "tty"
sd_session_get_class("13") → "user"
sd_session_get_display("13") → "n/a"
sd_session_get_remote_user("13") → "n/a"
sd_session_get_remote_host("13") → "n/a"
sd_session_get_seat("13") → "seat0"
sd_session_can_multi_seat("seat0") → no
sd_session_can_tty("seat0") → no
sd_session_can_graphical("seat0") → no
sd_uid_get_state(1000, …) → active
Assertion '!!k == !!r' failed at ../src/libsystemd/sd-login/test-login.c:191, function test_login(). Aborting.
Other functions in sd-login generally allow the output parameter to be NULL, in
which case only the number of items that would be stored in the array is returned.
Be nice and do the same here.
C.f. 0543105b0f.
This makes if /run/systemd/{seats,sessions,users} are missing, then
sd_get_seats(), sd_get_sessions() and sd_get_uids() return 0, that is,
an empty list, instead of -ENOENT.
The -ENOMEDIUM return value was introduced in v232-1001-g2977724b09,
('core: make hybrid cgroup unified mode keep compat /sys/fs/cgroup/systemd hierarchy'),
and would be returned by cg_pid_get_path_shifted(), but the documented and
expected return value is -ENODATA. Let's just catch ENXIO/ENOMEDIUM and translate
it to ENODATA in all cases.
Complements 171f8f591f, fixes#6012.
test-login.c is largely rewritten to use _cleanup_ and give more meaningful
messages (function names are used instead of creative terms like "active
session", so that when something unexpected is returned, it's much easier to
see what function is responsible).
The monitoring part is only activated if '-m' is passed on the command line.
It runs against the information from /run/systemd/ in the live system, but that
should be OK: logind/sd-login interface is supposed to be stable and both
backwards and forwards compatible.
If not running in a login session, some tests are skipped.
Those two changes together mean that it's possible to run test-login in the
test suite.
Tests for sd_pid_get_{unit,user_unit,slice} are added.
sd_seat_get_sessions returns two arrays, that in principle should always match:
the session names and corresponding uids. The second array could be shorter only
if parsing or uid conversion fails. But in that case there is no way to tell
*which* uid is wrong, so they are *all* useless. It's better to simplify things and
just return an error if parsing fails.
As described by Luke Shumaker:
sd_seat_get_sessions looks at /run/systemd/seats/${seat_name}:SESSIONS to get
the list of sessions (which I believe is correct), and at
/run/systemd/seats/${seat_name}:ACTIVE_SESSIONS for the list of users (which
I believe is incorrect); I believe that it should look at the UIDS field for
the list of users. As far as I can tell, the ACTIVE_SESSIONS field is never
even present in the seats file. I also believe that this has been broken
since the function was first committed almost 6 years ago.
Fixes#5743.
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.
There are more than enough calls doing string manipulations to deserve
its own files, hence do something about it.
This patch also sorts the #include blocks of all files that needed to be
updated, according to the sorting suggestions from CODING_STYLE. Since
pretty much every file needs our string manipulation functions this
effectively means that most files have sorted #include blocks now.
Also touches a few unrelated include files.
This seems to be an oversight from:
707b66c663
We have to return ENODATA instead of ENOENT if a requested entry is
non-present. Also fix the call-site in udev to check for these errors.
This adds a new sd_pid_get_cgroup() call to sd-login which may be used
to query the control path of a process. This is useful for programs when
making use of delegation units, in order to figure out which subtree has
been delegated.
In light of the unified control group hierarchy this is finally safe to
do, hence let's add a proper API for it, to make it easier to use this.
Makre sure we always return sensible errors for the various, following
the same rules, and document them in a comment in sd-login.c. Also,
update all relevant man pages accordingly.
This simply factors out the uid validation checks from parse_uid() and
uses them everywhere. This simply verifies that the passed UID is
neither 64bit -1 nor 32bit -1.
let's return ENXIO whenever we don't know something rather than ENOENT.
ENOENT suggests this was really about a file or directory, while ENXIO
is a more generic "not found" indicator.
When enumerating machines from /run, and when accepting machine names
for operations, be more strict and always validate.
Note that these checks are strictly speaking unnecessary, since
enumeration happens only on the trusted /run...
As it turns out machine_name_is_valid() does the exact same thing as
hostname_is_valid() these days, as it just invoked that and checked the
name length was < 64. However, hostname_is_valid() checks the length
against HOST_NAME_MAX anyway (which is 64 on Linux), hence any
additional check is redundant.
We hence replace machine_name_is_valid() by a macro that simply maps it
to hostname_is_valid() but sets the allow_trailing_dot parameter to
false. We also move this this call to hostname-util.h, to the same place
as the hostname_is_valid() declaration.
Lennart Poettering