Most of our NMSetting properties are based around GObject properties,
and thus the tooling to convert a NMSetting to/from GVariant consists
of getting/setting a GValue.
We can do better.
For most of such properties we also define a C getter function, which
we can call with less overhead. All we need is to hook the C getter with
the property meta data.
As example, implement it for "connection.autoconnect".
The immediate goal of this is to reduce the overhead of to_dbus. But
note that also for comparison of two properties, there is the default
implementation which is used by the majority of properties. This
implementation converts the properties first to GVariant (via
to_dbus_fcn) and then compares the variants. What this commit also does,
is to hook up the property meta data with the C-getters. This is one step
towards also more efficiently compare properties using the naive C
getters. Likewise, the keyfile writer use g_object_get_property().
It also could do better.
If a property can be converted to D-Bus, then always set the
to_dbus_fcn() handler. The only caller of to_dbus_fcn() is
property_to_dbus(), so this means that property_to_dbus()
has no more default implementation and always delegates to
to_dbus_fcn().
The code is easier to understand if all properties implement
to_dbus_fcn() the same way.
Also, there is supposed to be a split between NMSettInfoProperty (info about
the property) and NMSettInfoPropertType (the type). The idea is that
each property (obviously) requires its distinct NMSettInfoProperty, but
they can share a common type implementation.
With NMSettInfoPropertType.gprop_to_dbus_fcn that is often violated because
many properties that implement NMSettInfoPropertType.gprop_to_dbus_fcn
require a special type implementation. As such, gprop_to_dbus_fcn should
be part of the property info and not the property type. The first step towards
that is unifying all properties to use to_dbus_fcn().
When subclassing a GObject type, the class and object structs
must be available and defined in the header.
For libnm, and in particular for NMSetting classes, we don't want
users to subclass NMSetting. It also doesn't work, because libnm
has internal code that is necessary to hook up the NMSetting class.
You cannot define your own type and make it work together with
libnm.
Having the structs in public headers limits what we can do with them.
For example, we could embed the private data directly in the structures
and avoid the additional indirection.
This is an API break, but for something that most likely nobody cares
about. Or better, nobody should care about. API is not what is
accidentally defined in a header, API was the library provides to
meaningfully use. Subclassing these types is not meaningful and was
only accidentally possible so far.
Only hide the structs for now. More cleanup is possible later. We shall
however aim to keep the padding and struct layout to not also break ABI.
(cherry picked from commit e46d484fae)
So far, we didn't verify the secondary connections at all.
But these really are supposed to be UUIDs.
As we now also normalize "connection.uuid" to be in a strict
format, the user might have profiles with non-normalized UUIDs.
In that case, the "connection.uuid" would be normalized, but
"connection.secondaries" no longer matches. We can fix that by
also normalizing "connection.secondaries". OK, this is not a very good
reason, because it's unlikely to affect any users in practice ('though
it's easy to reproduce).
A better reason is that the secondary setting really should be well
defined and verified. As we didn't do that so far, we cannot simply
outright reject invalid settings. What this patch does instead, is
silently changing the profile to only contain valid settings.
That has it's own problems, like that the user setting an invalid
value does not get an error nor the desired(?) outcome.
But of all the bad choices, normalizing seems the most sensible
one.
Note that in practice, most client applications don't rely on setting
arbitrary (invalid) "UUIDs". They simply expect to be able to set valid
UUIDs, which they still are. For example, nm-connection-editor presents
a drop down list of VPN profile, and nmcli also resolves connection IDs
to the UUID. That is, clients already have an intimate understanding of
this setting, and don't blindly set arbitrary values. Hence, this
normalization is unlikely to hit users in practice. But what it gives
is the guarantee that a verified connection only contains valid UUIDs.
Now all UUIDs will be normalized, invalid entries removed, and the list
made unique.
GSList requires an additional allocation for the container struct for each
element. Also, it does not have O(1) direct access. It's a pretty bad
data structure, especially if the underlying data is in form of a strv
array.
Use a GArray instead and the nm_strvarray_*() helpers.
For example for NM_SETTING_CONNECTION_SECONDARIES, the user can set
the GObject property to a string list that includes empty strings.
The C accessors (add/remove-by-value) should also accept any strings that
are accepted otherwise. Asserting against empty strings is wrong. If the
setting wants to reject empty strings, then it should use verify().
For NetworkManager profiles, "connection.uuid" is the identifier of the
profile. It is supposed to be a UUID, however:
- the UUID was not ensured to be all-lower case. We should make sure
that our UUIDs are in a consistent manner, so that users can rely
on the format of the string.
- the UUID was never actually interpreted as a UUID. It only was some
opaque string, that we use as identifier. We had nm_utils_is_uuid()
which checks that the format is valid, however that did not fully
validate the format, like it would accept "----7daf444dd78741a59e1ef1b3c8b1c0e8"
and "549fac10a25f4bcc912d1ae688c2b4987daf444d" (40 hex characters).
Both invalid UUIDs and non-normalized UUID should be normalized. We
don't want to break existing profiles that use such UUIDs, thus we don't
outright reject them. Let's instead mangle them during
nm_connection_normalize().
"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.
2021-02-18 19:46:51 +01:00
Renamed from libnm-core/nm-setting-connection.c (Browse further)
