Currently, pty_forward_set_ignore_vhangup() is only used for disabling
the flag. To make the function also disable PTY_FORWARD_IGNORE_INITIAL_VHANGUP
flag, this renames it to pty_forward_honor_vhangup().
Also, for consistency, pty_forward_get_ignore_vhangup() and
ignore_vhangup() are replaced with pty_forward_vhangup_honored().
So far, machined strictly tracked the "leader" process of a machine,
i.e. the topmost process that is actually the payload of the machine.
Its runtime also defines the runtime of the machine, and we can directly
interact with it if we need to, for example for containers to join the
namespaces, or kill it.
Let's optionally also track the "supervisor" process of a machine, i.e.
the host process that manages the payload if there is one. This is
generally useful info, but in particular is useful because we might need
to communicate with it to shutdown a machine without cooperation of the
payload. Traditionally we did this by simply stopping the unit of the
machine, but this is not doable now that the host machined can be used
to track per-user machines.
In the long run we probably want a more bespoke protocol between
machined and supervisors (so that we can execute other commands too,
such as request cooperative reboots/shutdowns), but that's for later.
Some environments call the concept "monitor" rather than "supervisor" or
use some other term. I stuck to "supervisor" because nspawn uses this,
and ultimately one name is as good as another.
And of course, in other implementations of VM managers of containers
there might not be a single process tracking each VM/container. Because
of this, the concept of a supervisor is optional.
The difference between these two operations are large: one is relatively
superficial: for "registration" all resources remain associated with the
invoking user, only the cgroup is reported to machined which then keeps
track of the machine, too. OTOH "creation" a scope is allocated in
system context, hence the invoked code will be owned by the system, and
its resource usage charged against the system.
Hence, use two distinct polkit actions for this, so that we can relax
access to registration, but keep access to creation tough.
Now that unpriv clients can register machines, let's register their UID
too. This allows us to do two things:
1. make sure the scope delegation is assigned to the right UID (so that
the unpriv user can actually create cgroups below the delegated
scope)
2. permit certain types of access (i.e. killing, or pty access) to the
client without auth if it owns the machine.
All other status output lines use tabs, use that for the ID shift line
too. otherwise output will appear unaligned if log viewers have fixed
tab stop positions.
We use symbols provided by unistd.h without including it. E.g.
open(), close(), read(), write(), access(), symlink(), unlink(), rmdir(),
fsync(), syncfs(), lseek(), ftruncate(), fchown(), dup2(), pipe2(),
getuid(), getgid(), gettid(), getppid(), pipe2(), execv(), _exit(),
environ, STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO, F_OK, and their
friends and variants, so on.
Currently, unistd.h is indirectly included mainly in the following two paths:
- through missing_syscall.h, which is planned to covert to .c file.
- through signal.h -> bits/sigstksz.h, which is new since glibc-2.34.
Note, signal.h is included by sd-eevent.h. So, many source files
indirectly include unistd.h if newer glibc is used.
Currently, our baseline on glibc is 2.31. We need to support glibc older
than 2.34, but unfortunately, we do not have any CI environments with
such old glibc. CIFuzz uses glibc-2.31, but it builds only fuzzers, and
many files are even not compiled.
These method calls all already have polkit hookup, hence actually allow
them to go through on all levels.
This is mostly playing catchup with a variety of calls added over the
years.
The method call already does a PK check, it was just forgotten to
allowlist this in the dbus policy. And in the dbus vtable for
OpenMachinePTY() call. (It was allowlisted in the per-machine
vtable…)
Anyway, clean this up.
git grep -l 'Failed to open /'|xargs sed -r -i 's|"Failed to open (/[^ ]+): %m"|"Failed to open %s: %m", "\1"|g'
git grep -l $'Failed to open \'/'|xargs sed -r -i $'s|"Failed to open \'(/[^ ]+)\': %m"|"Failed to open %s: %m", "\\1"|g'
git grep -l "Failed to open /"|xargs sed -r -i $'s|"Failed to open (/[^ ]+), ignoring: %m"|"Failed to open %s, ignoring: %m", "\\1"|g'
+ some manual fixups.
Let's check the leader alive state, and let's log about dbus errors.
This mimics (but is not quite identical to) what we do these days in
logind for GC'ing user sessions.
This effectively renames cg_is_empty_recursive() to cg_is_empty().
Note that all existing code calls the former and not the latter,
hence with cgv1 support being dropped it's trivial to consult
cgroup.events directly for populated state everywhere.
Additionally, use more generic cg_get_keyed_attribute() helper
rather than cg_read_event().
We need to protect us from recycled PIDs here like everywhere else: once
we read data from /proc/$PID/ we need to validate that $PID still points
to the original pidfd.
clang-include-cleaner has a hard time figuring out unused includes
with all the macro string concatentation we're doing in test_table().
Let's help it out a little by also passing the enum type into test_table().
While technically not needed, this makes the tests a bit more self-descriptive
and not really much more verbose so it feels like a good chance regardless,
even if the primary purpose is to help clang-include-cleaner figure out
used and unused includes.
Instead of using run-clang-tidy.py with its own scheduling, let's
just gather a list of source files ourselves and then use that to
add a unit test for each source file that runs clang-tidy on the
source file.
We also add a bit of logic to run clang-tidy on most header files
as well for extra coverage. This uncovered various header files that
were not standalone so this commit also includes fixes to make sure
the clang-tidy tests are all green.
We can also use this in a later commit to run clang-include-cleaner
on each source file in the same way.
Also, let's deflatten the lists of sources in preparation for the
next commit at the same time.
In systemctl, we split out systemctl-main.c to make sure the definition
of main() is in a separate object which allows us to extract the systemctl.c
object and link it in the fuzzer target without getting a multiple definition
error when linking.
Currently, when we want to add unit tests for code that is compiled into
an executable, we either compile the code at least twice (once for the
executable, and once for each test that uses it) or we create a static
library which is then used by both the executable and all the tests.
Both of these options are not ideal, compiling source files more than
once slows down the build for no reason and creating the intermediate
static libraries takes a lot of boilerplate.
Instead, let's use the extract_objects() method that meson exposes on
build targets. This allows us to extract the objects corresponding to
specific source files and use them in other executables. Because we
define all executables upfront into a dictionary, we integrate this into
the dictionary approach by adding two new fields:
- 'extract' takes a list of files for which objects should be extracted.
The extracted objects are stored in a dict keyed by the executable name
from which they were extracted.
- 'objects' takes the name of an executable from which the extracted
objects should be added to the current executable.
One side effect of this approach is that we can't build test executables
anymore without building the main executable, so we stop building test
executables unless we're also building the main executable. This allows
us to switch to using subdir_done() in all of these subdirectories to skip
parsing them if the corresponding component is disabled.
These changes get me down from 2439 => 2403 ninja targets on a full rebuild
from scratch.
Let's move some logic from _DEFINE_MAIN_FUNCTION() and other places
in main-func.h into functions that we implement in main-func.c to
allow moving some included headers from the header to the .c file.