When we make runtime only changes, we may leave the profile in persistent
storage and store a overlay profile in /run. However, in various cases we need
to remember the original path.
Add code to store and retrieve that path from the keyfile.
Note that this data is written inside the keyfile in /run. That is because
this piece of information really depends on that particular keyfile, and not
on the profile/UUID. That is why we write it to the [.nmmeta] section of the
keyfile and not to the .nmmeta file (which is per-UUID).
This patch only adds the backend to write and load the setting from
disk. It's not yet used.
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
We may want to store meta-data for a profile to disk. The immediate
need are "tombstones": markers that the particular UUID is shadowed
and the profile does not exist (despite being in read-only location).
Change the filename of these symlinks from
".loaded-${UUID}.nmconnection"
to
"${UUID}.nmmeta"
The leading dot is not desirable as tools tend to hide such files.
Use a different scheme for the filename that does not have the leading dot.
Note that nm_keyfile_utils_ignore_filename() would also ignore ".nmmeta"
as not a valid keyfile. This is just what we want, and influences the
choice of this file suffix.
Also, "nmmeta" is a better name, because this name alludes that there is
a wider use for the file: namely to have addtional per-profile metadata.
That is regardless that the upcoming first use will be only to store symlinks
to "/dev/null" to indicate the tombstones.
Note that per-profile metadata is not new. Currently we write the files
/var/lib/NetworkManager/{seen-bssids,timestamps}
that have a similar purpose. Maybe the content from these files could one
day be migrated to the ".nmmeta" file. The naming scheme would make it
suitable.
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 "${F[@]}"
Check remaining lines with:
git grep -e '-\*-'
The ultimate purpose of this is to cleanup our files and eventually use
SPDX license identifiers. For that, first get rid of the boilerplate lines.
This code will be used later.
We want to remember which keyfiles are currently loaded (or hidden).
With the addition or multiple keyfile directories (soon), there are
two cases where this matters:
- if there are multiple keyfiles which reference the same UUID,
we can only load one of them. That is already a problem today
with only one keyfile directory, where multiple files can reference
the same UUID.
The implementation will pick the file based on priorities (like
the file modification date). However, the user may call explicitly
call `nmcli connection load`. In that case, we cannot reload
all files to find out whether the to be loaded file is hidden
according to the defined priorities. We cannot do that, because we
must not make decisions based on files on disk, which we are not told
to reload. So, during a `nmcli connection load` we must look at
unrelated files, to determine how to load the file.
Instead, we do allow the user to load any file, even if it would be
shadowed by other files. When we do that, we may want to persist which
file is currently loaded, so that a service restart and a `nmcli connection
reload` does not undo the load again. This can be later later be solved by
writing a symlink
"/var/run/NetworkManager/system-connections/.loaded-$UUID.nmkeyfile"
which targets the currently active file.
- if a profile was loaded from read-only persistant storage, the user
may still delete the profile. We also need to remember the deletion
of the file. That will be achieved by symlinking "/dev/null" as
"/etc/NetworkManager/system-connections/.loaded-$UUID.nmkeyfile".
Add helper functions to read and write these symlinks.
NM_CONFIG_KEYFILE_PATH_IN_MEMORY is now called NMS_KEYFILE_PATH_NAME_RUN.
This name seems odd in the current context, it will be more suitable
when we also have NMS_KEYFILE_PATH_NAME_LIB (for /usr/lib).
These utilities are concerned with valid file names (as NetworkManager
daemon requires it). This is relevant for everybody who wants to write
keyfile files directly. Hence, move it to libnm-core. Still as internal
API.
keyfile already supports omitting the "connection.id" and
"connection.uuid". In that case, the ID would be taken from the
keyfile's name, and the UUID was generated by md5 hashing the
full filename.
No longer do this during nm_keyfile_read(), instead let all
callers call nm_keyfile_read_ensure_*() to their liking. This is done
for two reasons:
- a minor reason is, that one day we want to expose keyfile API
as public API. That means, we also want to read keyfiles from
stdin, where there is no filename available. The implementation
which parses stdio needs to define their own way of auto-generating
ID and UUID. Note how nm_keyfile_read()'s API no longer takes a
filename as argument, which would be awkward for the stdin case.
- Currently, we only support one keyfile directory, which (configurably)
is "/etc/NetworkManager/system-connections".
In the future, we want to support multiple keyfile dirctories, like
"/var/run/NetworkManager/profiles" or "/usr/lib/NetworkManager/profiles".
Here we want that a file "foo" (which does not specify a UUID) gets the
same UUID regardless of the directory it is in. That seems better, because
then the UUID won't change as you move the file between directories.
Yes, that means, that the same UUID will be provided by multiple
files, but NetworkManager must already cope with that situation anyway.
Unfortunately, the UUID generation scheme hashes the full path. That
means, we must hash the path name of the file "foo" inside the
original "system-connections" directory.
Refactor the code so that it accounds for a difference between the
filename of the keyfile, and the profile_dir used for generating
the UUID.
Split out the functionality for auto-detecting the ID and UUID of
a connection. First of all, nm_keyfile_read() is already overcomplicated.
The next commit will require the caller to explicitly call these
functions.
Note that:
- we compile some source files multiple times. Most notably those
under "shared/".
- we include a default header "shared/nm-default.h" in every source
file. This header is supposed to setup a common environment by defining
and including parts that are commonly used. As we always include the
same header, the header must behave differently depending
one whether the compilation is for libnm-core, NetworkManager or
libnm-glib. E.g. it must include <glib/gi18n.h> or <glib/gi18n-lib.h>
depending on whether we compile a library or an application.
For that, the source files need the NETWORKMANAGER_COMPILATION #define
to behave accordingly.
Extend the define to be composed of flags. These flags are all named
NM_NETWORKMANAGER_COMPILATION_WITH_*, they indicate which part of the
build are available. E.g. when building libnm-core.la itself, then
WITH_LIBNM_CORE, WITH_LIBNM_CORE_INTERNAL, and WITH_LIBNM_CORE_PRIVATE
are available. When building NetworkManager, WITH_LIBNM_CORE_PRIVATE
is not available but the internal parts are still accessible. When
building nmcli, only WITH_LIBNM_CORE (the public part) is available.
This granularily controls the build.
This part contains static functions and variables to describe
settings. It is distinct from the mechanism to use them, or
access them.
Split it out.
It still uses clients/cli/common.h and clients/cli/utils.h
which shall be fixed next.
- 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)
Rather than randomly including one or more of <glib.h>,
<glib-object.h>, and <gio/gio.h> everywhere (and forgetting to include
"nm-glib-compat.h" most of the time), rename nm-glib-compat.h to
nm-glib.h, include <gio/gio.h> from there, and then change all .c
files in NM to include "nm-glib.h" rather than including the glib
headers directly.
(Public headers files still have to include the real glib headers,
since nm-glib.h isn't installed...)
Also, remove glib includes from header files that are already
including a base object header file (which must itself already include
the glib headers).
GKeyFile considers the order of the files, so add a possibility
to check whether to keyfiles are equal -- also with respect to
the order of the elements.
keyfile should become our main import/export format. It is desirable,
that a keyfile can contain every aspect of a connection.
For blob certificates, the writer in core daemon would always write
them to a file and convert the scheme to path.
This behavior is not great for a (hyptetical) `nmcli connection export`
command because it would have to export them somehow outside of keyfile,
e.g. by writing them to temporary files.
Instead, if the write handler does not handle a certificate, use a
default implementation in nm_keyfile_write() which adds the blob inside
the keyfile.
Interestingly, keyfile reader already supported reading certificate
blobs. But this legacy format accepts the blob as arbitrary
binary without marking the format and without scheme prefix.
Instead of writing the binary data directly, write it with a new
uri scheme "data:;base64," and encode it in base64.
Also go through some lengths to make sure that whatever path
keyfile plugin writes, can be read back again. That is, because
keyfile writer preferably writes relative paths without prefix.
Add nm_keyfile_detect_unqualified_path_scheme() to encapsulate
the detection of pathnames without file:// prefix and use it to
check whether the path name must be fully qualified.
These headers are not entirely private to libnm-core as they are also
used by keyfile plugin. Merge them to a new header file
nm-keyfile-internal.h so that the name makes the internal nature of the
header more apparent.
