Initially I thought I would use this somewhere else. Didn't do so far,
but this seems a useful function to have on its own because also
NMSettings is concerned about the relative priority of plugins.
Completely rework how settings plugin handle connections and how
NMSettings tracks the list of connections.
Previously, settings plugins would return objects of (a subtype of) type
NMSettingsConnection. The NMSettingsConnection was tightly coupled with
the settings plugin. That has a lot of downsides.
Change that. When changing this basic relation how settings connections
are tracked, everything falls appart. That's why this is a huge change.
Also, since I have to largely rewrite the settings plugins, I also
added support for multiple keyfile directories, handle in-memory
connections only by keyfile plugin and (partly) use copy-on-write NMConnection
instances. I don't want to spend effort rewriting large parts while
preserving the old way, that anyway should change. E.g. while rewriting ifcfg-rh,
I don't want to let it handle in-memory connections because that's not right
long-term.
--
If the settings plugins themself create subtypes of NMSettingsConnection
instances, then a lot of knowledge about tracking connections moves
to the plugins.
Just try to follow the code what happend during nm_settings_add_connection().
Note how the logic is spread out:
- nm_settings_add_connection() calls plugin's add_connection()
- add_connection() creates a NMSettingsConnection subtype
- the plugin has to know that it's called during add-connection and
not emit NM_SETTINGS_PLUGIN_CONNECTION_ADDED signal
- NMSettings calls claim_connection() which hocks up the new
NMSettingsConnection instance and configures the instance
(like calling nm_settings_connection_added()).
This summary does not sound like a lot, but try to follow that code. The logic
is all over the place.
Instead, settings plugins should have a very simple API for adding, modifying,
deleting, loading and reloading connections. All the plugin does is to return a
NMSettingsStorage handle. The storage instance is a handle to identify a profile
in storage (e.g. a particular file). The settings plugin is free to subtype
NMSettingsStorage, but it's not necessary.
There are no more events raised, and the settings plugin implements the small
API in a straightforward manner.
NMSettings now drives all of this. Even NMSettingsConnection has now
very little concern about how it's tracked and delegates only to NMSettings.
This should make settings plugins simpler. Currently settings plugins
are so cumbersome to implement, that we avoid having them. It should not be
like that and it should be easy, beneficial and lightweight to create a new
settings plugin.
Note also how the settings plugins no longer care about duplicate UUIDs.
Duplicated UUIDs are a fact of life and NMSettings must handle them. No
need to overly concern settings plugins with that.
--
NMSettingsConnection is exposed directly on D-Bus (being a subtype of
NMDBusObject) but it was also a GObject type provided by the settings
plugin. Hence, it was not possible to migrate a profile from one plugin to
another.
However that would be useful when one profile does not support a
connection type (like ifcfg-rh not supporting VPN). Currently such
migration is not implemented except for migrating them to/from keyfile's
run directory. The problem is that migrating profiles in general is
complicated but in some cases it is important to do.
For example checkpoint rollback should recreate the profile in the right
settings plugin, not just add it to persistent storage. This is not yet
properly implemented.
--
Previously, both keyfile and ifcfg-rh plugin implemented in-memory (unsaved)
profiles, while ifupdown plugin cannot handle them. That meant duplication of code
and a ifupdown profile could not be modified or made unsaved.
This is now unified and only keyfile plugin handles in-memory profiles (bgo #744711).
Also, NMSettings is aware of such profiles and treats them specially.
In particular, NMSettings drives the migration between persistent and non-persistent
storage.
Note that a settings plugins may create truly generated, in-memory profiles.
The settings plugin is free to generate and persist the profiles in any way it
wishes. But the concept of "unsaved" profiles is now something explicitly handled
by keyfile plugin. Also, these "unsaved" keyfile profiles are persisted to file system
too, to the /run directory. This is great for two reasons: first of all, all
profiles from keyfile storage in fact have a backing file -- even the
unsaved ones. It also means you can create "unsaved" profiles in /run
and load them with `nmcli connection load`, meaning there is a file
based API for creating unsaved profiles.
The other advantage is that these profiles now survive restarting
NetworkManager. It's paramount that restarting the daemon is as
non-disruptive as possible. Persisting unsaved files to /run improves
here significantly.
--
In the past, NMSettingsConnection also implemented NMConnection interface.
That was already changed a while ago and instead users call now
nm_settings_connection_get_connection() to delegate to a
NMSimpleConnection. What however still happened was that the NMConnection
instance gets never swapped but instead the instance was modified with
nm_connection_replace_settings_from_connection(), clear-secrets, etc.
Change that and treat the NMConnection instance immutable. Instead of modifying
it, reference/clone a new instance. This changes that previously when somebody
wanted to keep a reference to an NMConnection, then the profile would be cloned.
Now, it is supposed to be safe to reference the instance directly and everybody
must ensure not to modify the instance. nmtst_connection_assert_unchanging()
should help with that.
The point is that the settings plugins may keep references to the
NMConnection instance, and so does the NMSettingsConnection. We want
to avoid cloning the instances as long as they are the same.
Likewise, the device's applied connection can now also be referenced
instead of cloning it. This is not yet done, and possibly there are
further improvements possible.
--
Also implement multiple keyfile directores /usr/lib, /etc, /run (rh #1674545,
bgo #772414).
It was always the case that multiple files could provide the same UUID
(both in case of keyfile and ifcfg-rh). For keyfile plugin, if a profile in
read-only storage in /usr/lib gets modified, then it gets actually stored in
/etc (or /run, if the profile is unsaved).
--
While at it, make /etc/network/interfaces profiles for ifupdown plugin reloadable.
--
https://bugzilla.gnome.org/show_bug.cgi?id=772414https://bugzilla.gnome.org/show_bug.cgi?id=744711https://bugzilla.redhat.com/show_bug.cgi?id=1674545
As nm_settings_plugin_initialize() could not fail (it returned no value indicating
failure), there is no reason to explicitly call this. Instead just
initialize the plugin when needed.
Also, we don't need the plugin to initialize early before nm_settings_plugin_get_connections().
We no longer add these. If you use Emacs, configure it yourself.
Also, due to our "smart-tab" usage the editor anyway does a subpar
job handling our tabs. However, on the upside every user can choose
whatever tab-width he/she prefers. If "smart-tabs" are used properly
(like we do), every tab-width will work.
No manual changes, just ran commands:
F=($(git grep -l -e '-\*-'))
sed '1 { /\/\* *-\*- *[mM]ode.*\*\/$/d }' -i "${F[@]}"
sed '1,4 { /^\(#\|--\|dnl\) *-\*- [mM]ode/d }' -i "${F[@]}"
Check remaining lines with:
git grep -e '-\*-'
The ultimate purpose of this is to cleanup our files and eventually use
SPDX license identifiers. For that, first get rid of the boilerplate lines.
NMSettingsPlugin was a glib interface, not a regular GObject
instance. Accordingly, settings plugins would implement this interface
instead of subclassing a parent type.
Refactor the code, and make NMSettingsPlugin a GObject type. Plugins
are now required to subclass this type.
Glib interfaces are more cumbersome than helpful. At least, unless
there is a good reason for using them.
Our settings plugins are all internal API and are entirely under
our control. It also means, this change is fine, as there are no
implementations outside of this source tree.
Using interfaces do would allow more flexibility in implementing the
settings plugin.
For example, the plugin would be able to derive from any other GObject
type, like NMKimchiRefrigerator. But why would we even? Let's not add monster
classes that implement house appliances beside NMSettingsPluginInterface.
The settings plugin should have one purpose only: being a settings plugin.
Hence, requiring it to subclass NMSettingsPlugin is more than resonable. We
don't need interfaces for this.
Now that NMSettingsPlugin is a regular object instance, it may also have
state, and potentially could provide common functionality for the plugin
implementation -- if that turns out to be useful. Arguably, an interface can
have state too, for example by attaching the state somewhere else (like
NMConnection does). But let's just say no.
On a minor note, this also avoids some tiny overhead that comes with
glib interfaces.
The virtual function init() naturally leads to calling the wrapper
function nm_settings_plugin_init(). However, such ${TYPE}_init() functions
are generated by G_DEFINE_TYPE().
Rename to avoid the naming conflict, which will matter next, when the
interface will be converted to a regular GObject class.
Note that while these are settings plugin, there is no public
or stable API which we need to preserve.
In practice, this should only matter when there are multiple
header files with the same name. That is something we try
to avoid already, by giving headers a distinct name.
When building NetworkManager itself, we clearly want to use
double-quotes for including our own headers.
But we also want to do that in our public headers. For example:
./a.c
#include <stdio.h>
#include <nm-1.h>
void main() {
printf ("INCLUDED %s/nm-2.h\n", SYMB);
}
./1/nm-1.h
#include <nm-2.h>
./1/nm-2.h
#define SYMB "1"
./2/nm-2.h
#define SYMB "2"
$ cc -I./2 -I./1 ./a.c
$ ./a.out
INCLUDED 2/nm-2.h
Exceptions to this are
- headers in "shared/nm-utils" that include <NetworkManager.h>. These
headers are copied into projects and hence used like headers owned by
those projects.
- examples/C
- don't include "nm-default.h" in header files. Every source file must
include as first header "nm-default.h", thus our headers get the
default include already implicitly.
- we don't support compiling NetworkManager itself with a C++ compiler. Remove
G_BEGIN_DECLS/G_END_DECLS from internal headers. We do however support
users of libnm to use C++, thus they stay in public headers.
(cherry picked from commit f19aff8909)
A GObject interface, like a class, has two different C types
associated with it; the type of the "class" struct (eg, GObjectClass,
GFileIface), and the type of instances of that class/interface (eg,
GObject, GFile).
NetworkManager was doing this wrong though, and using the same C type
to point to both the interface's class struct and to instances of the
interface. This ends up not actually breaking anything, since for
interface types, the instance type is a non-dereferenceable dummy type
anyway. But it's wrong, since if, eg, NMDeviceFactory is a struct type
containing members "start", "device_added", etc, then you should not
be using an NMDeviceFactory* to point to an object that does not
contain those members.
Fix this by splitting NMDeviceFactory into NMDeviceFactoryInterface
and NMDeviceFactory; by splitting NMConnectionProvider into
NMConnectionProviderInterface and NMConnectionProvider; and by
splitting NMSettingsPlugin into NMSettingsPluginInterface and
NMSettingsPlugin; and then use the right types in the right places.
As a bonus, this also lets us now use G_DEFINE_INTERFACE.
Since there have not been separate system and user settings services
since 0.8, the "system" in NMSystemConfigInterface is kind of
meaningless. Rename it to NMSettingsPlugin, which describes what it
does better.
This is just:
git mv src/settings/nm-system-config-interface.h src/settings/nm-settings-plugin.h
git mv src/settings/nm-system-config-interface.c src/settings/nm-settings-plugin.c
perl -pi -e 's/SystemConfigInterface/SettingsPlugin/g;' \
-e 's/system_config_interface/settings_plugin/g;' \
-e 's/system-config-interface/settings-plugin/g;' \
-e 's/SYSTEM_CONFIG_INTERFACE/SETTINGS_PLUGIN/g;' \
-e 's/sc_plugin/settings_plugin/g;' \
-e 's/SC_PLUGIN/SETTINGS_PLUGIN/g;' \
-e 's/SC_IS_PLUGIN/SETTINGS_IS_PLUGIN/g;' \
-e 's/SC_TYPE_PLUGIN/SETTINGS_TYPE_PLUGIN/g;' \
-e 's/SCPlugin/SettingsPlugin/g;' \
-e 's/nm_system_config_factory/nm_settings_plugin_factory/g;' \
$(find src/settings -type f)
(followed by some whitespace fixups in nm-settings-plugin.c, and a
Makefile.am fix for the rename)
2015-09-10 13:43:47 -04:00
Renamed from src/settings/nm-system-config-interface.h (Browse further)
