Preparation for later commits, but I think this one makes
a ton of sense on its own. When debug logging is enabled
it's otherwise difficult to dig up the portion of journal
for transaction construction.
Let's extend pid1's varlink interface and add a Describe method to
get the global Manager object information as a JSON object
(io.systemd.Manager.Describe).
Because the new varlink interface should be available on both the
user managers and the system manager, we also make the necessary
changes to expose a varlink server on user managers.
Currently there are various circular dependencies between headers
in core/. Let's get rid of these by making judicious use of forward
declarations and moving includes into implementation files instead of
having them in header files.
Getting rid of circular header includes simplifies the code and makes
various clang based tooling such as iwyu work much better on our code.
The most important change is getting rid of the manager.h include in
unit.h which is possible thanks to the previous commits. We also move
the OOMPolicy and StatusType enums to unit.h to remove the need for
other unit headers to include manager.h to get access to these enums.
Admittedly, some of our glyphs _are_ special, e.g. "O=" for SPECIAL_GLYPH_TOUCH ;)
But we don't need this in the name. The very long names make some invocations
very wordy, e.g. special_glyph(SPECIAL_GLYPH_SLIGHTLY_UNHAPPY_SMILEY).
Also, I want to add GLYPH_SPACE, which is not special at all.
If we unexpectly disconnect from the bus, systemd would end up dropping
the list of subscribers, which breaks the ability of clients like logind
to monitor the state of units.
Stash the list of subscribers into the deserialized state in the event
of a disconnect so that when we recover we can renew the broken
subscriptions.
---
Fixes: #8672#26744
These new calls will do three things:
1. in case of FILE* stuff: flush any pending bytes onto the fd, just in
case
2. seal the backing memfd
3. seek back to the beginning.
Note that this adds sealing to serialization: once we serialized fully,
we'll seal the thing off for further modifications, before we pass the
fd over to the target process. This should add a bit of robustness, and
maybe finds a bug or two one day, if we accidentally write to a
serialization that is complete.
This field indicates whether READY=1 has been sent to
the service manager/supervisor. Whenever we reload/reexec/soft-reboot,
manager_send_reloading() always resets it to false first,
so that READY=1 is sent after reloading finishes. Hence
we utterly get "false" at all times. Kill it.
Follow-up for 6906c028e8
The mentioned commit uses access() to check if varlink socket
already exists in the filesystem, but that isn't sufficient.
> Varlink sockets are not serialized until v252, so upgrading from
> v251 or older means we will not listen anymore on the varlink sockets.
>
> See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1074789
> for more details as this was found when updating from Debian Bullseye to a new version.
After this commit, the set up of varlink_server is effectively
split into two steps. manager_varlink_init_system(), which is
called after deserialization, would no longer skip listening
even if Manager.varlink_server is in place, but actually
check if we're listening on desired sockets.
Then, manager_deserialize() can be switched back to using
manager_setup_varlink_server().
Alternative to #33817
Co-authored-by: Luca Boccassi <bluca@debian.org>
It's time. sd-json was already done earlier in this cycle, let's now
make sd-varlink public too.
This is mostly just a search/replace job of epical proportions.
I left some functions internal (mostly IDL handling), and I turned some
static inline calls into regular calls.
This adds an AF_UNIX socket pair to the manager that we can collect
handoff timestamp messages on.
The idea is that forked off children send a datagram with a timestamp
and we use its sender PID to match it against the right forked off
process.
This part only implements the receiving side: a socket is created, and
listened on. Received datagrams are parsed, verified and then dispatched
to the interested units.
Follow-up for 8c15bf36e1
I just realized that we should not serialize the number
of internal enum, as that's subject to changes and such
changes would be hard to notice. Let's serialize strings
properly instead.
Same reason as the reload, reexec is disruptive and it requires the
same privileges, so if somebody wants to limit reloads, they'll also
want to limit reexecs, so use the same setting.
Currently, when we deserialize an fd we do a lot of manual work. Add a
common helper that makes this more robust and uniform.
Note that this sometimes changes behaviour slightly, but in ways that
shouldn't really matter: if we fail to deserialize an fd correctly we'll
unset (i.e. set to -EBADF) the fd in the deserialized data structure.
Previously, we'd leave the old value in place.
This should not change effective result (as in either case we'll be in a
bad state afterwards, just once we mix old/invalidated state with new
state, while now we'll reset the state explicitly to invalidated state
on failure). In particular as deserialization starts from an empty
structure generally, hence the old value should be unset anyway.
Another slight change is that if we fail to deserialize some object half
way, and we already have taken out one fd from the serialized fdset
we'll now just close it instead of returning it to/leaving it in the
fdset. Given that such "orphaned" fds are blanket closed after
deserialization finishes this also shouldn't change behaviour IRL.
Also, the idle_pipe was previously incorrectly serialized: we'd
serialize invalidated fds, which would fail, but because parsing errors
on this were ignored on the deserializatin noone noticed. This is fixed.
Before this PR, if m->varlink_server is not yet set up during
deserialization, we call manager_setup_varlink_server rather than
manager_varlink_init, the former of which doesn't setup varlink
addresses, but only binds to methods. This results in that
newly-added varlink addresses not getting created if deserialization
takes place.
Therefore, let's switch to manager_varlink_init, and add some
sanity checks to it in order to prevent listening on the same
address twice.
Fixes#29373
Replaces #29421
Dump*() methods can take quite some time due to the amount of data to
serialize, so they can potentially stall the manager. Make them
privileged, as they are debugging tools anyway. Use a new 'dump'
capability for polkit, and the 'reload' capability for SELinux, as
that's also non-destructive but slow.
If the caller is not privileged, allow it but rate limited to 10 calls
every 10 minutes.
-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.
I changed imports of util.h to initrd-util.h, or added an import of
initrd-util.h, to keep compilation working. It turns out that many files didn't
import util.h directly.
When viewing the patch, don't be confused by git rename detection logic:
a new .c file is added and two functions moved into it.
Add support for managing and configuring watchdog pretimeout values if
the watchdog hardware supports it. The ping interval is adjusted to
account for a pretimeout so that it will still ping at half the timeout
interval before a pretimeout event would be triggered. By default the
pretimeout defaults to 0s or disabled.
The RuntimeWatchdogPreSec config option is added to allow the pretimeout
to be specified (similar to RuntimeWatchdogSec). The
RuntimeWatchdogPreUSec dbus property is added to override the pretimeout
value at runtime (similar to RuntimeWatchdogUSec). Setting the
pretimeout to 0s will disable the pretimeout.