Of course, blocking and synchronous code is much simpler. But it's also
fundamentally wrong to block while we talk to systemd-hostnamed.
Refactor to use async operations.
We get the hostname via D-Bus (from hostnamed) or read it from file.
In the latter case, it is not ensured that it's valid UTF-8.
Non-UTF-8 "strings" are bad, because we might try to expose them
on D-Bus, log them or other bad things.
Sanitize the string by using backslash escaping. Maybe we should
outright reject such binary nonsense, but it's not done here,
for no strong reasons.
We have at least static and transient hostnames. Let's be clear which
one we are talking about.
Note that also NM_SETTINGS_HOSTNAME gets renamed to
NM_SETTINGS_STATIC_HOSTNAME, because it seems clearer.
The only purpose of NM_SETTINGS_STATIC_HOSTNAME is to be the backing
property for the "Hostname" D-Bus property for the NMDBusObject glue.
So, while the new name makes more sense to me, it's now also
inconsistent with it's primary use (the D-Bus property). Still...
We use clang-format for automatic formatting of our source files.
Since clang-format is actively maintained software, the actual
formatting depends on the used version of clang-format. That is
unfortunate and painful, but really unavoidable unless clang-format
would be strictly bug-compatible.
So the version that we must use is from the current Fedora release, which
is also tested by our gitlab-ci. Previously, we were using Fedora 34 with
clang-tools-extra-12.0.1-1.fc34.x86_64.
As Fedora 35 comes along, we need to update our formatting as Fedora 35
comes with version "13.0.0~rc1-1.fc35".
An alternative would be to freeze on version 12, but that has different
problems (like, it's cumbersome to rebuild clang 12 on Fedora 35 and it
would be cumbersome for our developers which are on Fedora 35 to use a
clang that they cannot easily install).
The (differently painful) solution is to reformat from time to time, as we
switch to a new Fedora (and thus clang) version.
Usually we would expect that such a reformatting brings minor changes.
But this time, the changes are huge. That is mentioned in the release
notes [1] as
Makes PointerAligment: Right working with AlignConsecutiveDeclarations. (Fixes https://llvm.org/PR27353)
[1] https://releases.llvm.org/13.0.0/tools/clang/docs/ReleaseNotes.html#clang-format
This function is badly named, because it has no NMHostnameManager self
argument. It's just a simple function that entirely operates on a string
argument.
Move it away from "nm-hostname-manager.h" to "libnm-glib-aux/nm-shared-utils.h".
Hostname handling is complicated enough. Simple string validation
functions should not obscure the view on the complicated parts.
"libnm-core/" is rather complicated. It provides a static library that
is linked into libnm.so and NetworkManager. It also contains public
headers (like "nm-setting.h") which are part of public libnm API.
Then we have helper libraries ("libnm-core/nm-libnm-core-*/") which
only rely on public API of libnm-core, but are themself static
libraries that can be used by anybody who uses libnm-core. And
"libnm-core/nm-libnm-core-intern" is used by libnm-core itself.
Move "libnm-core/" to "src/". But also split it in different
directories so that they have a clearer purpose.
The goal is to have a flat directory hierarchy. The "src/libnm-core*/"
directories correspond to the different modules (static libraries and set
of headers that we have). We have different kinds of such modules because
of how we combine various code together. The directory layout now reflects
this.
Currently "src/" mostly contains the source code of the daemon.
I say mostly, because that is not true, there are also the device,
settings, wwan, ppp plugins, the initrd generator, the pppd and dhcp
helper, and probably more.
Also we have source code under libnm-core/, libnm/, clients/, and
shared/ directories. That is all confusing.
We should have one "src" directory, that contains subdirectories. Those
subdirectories should contain individual parts (libraries or
applications), that possibly have dependencies on other subdirectories.
There should be a flat hierarchy of directories under src/, which
contains individual modules.
As the name "src/" is already taken, that prevents any sensible
restructuring of the code.
As a first step, move "src/" to "src/core/". This gives space to
reorganize the code better by moving individual components into "src/".
For inspiration, look at systemd's "src/" directory.
https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/merge_requests/743
