In NetworkManager.conf, we can only configure one "[main].dhcp="
for both address families. Consequently, NMDhcpClientFactory
represents also both address families. However, most plugins
don't support IPv4 and IPv6 together.
Thus, if a plugin does not support an address family, we fallback
to the implementation of the "internal" plugin.
Slightly rework the code how that is done. Instead of having
a "get_type()" and "get_type_per_addr_family()" callback, have
an IPv4 and IPv6 getter.
clang 3.4.2-9.el7 dislikes expressions in the form
int v;
struct {
typeof(({ v; })) _field;
} x;
error: statement expression not allowed at file scope
typeof( ({ v; }) ) _field;
^
That is, if the argument to typeof() is an expression statement. But this is
what
nm_hash_update_val(&h, ..., NM_HASH_COMBINE_BOOLS(...))
expands to. Rework NM_HASH_COMBINE_BOOLS() to avoid the expression statement.
We still have the static assertion for the size of the return type.
We no longer have the _nm_hash_combine_bools_type typedef. It really
wasn't needed, and the current variant is always safe without it.
Fixes: 23adeed244 ('glib-aux: use NM_VA_ARGS_FOREACH() to implement NM_HASH_COMBINE_BOOLS()')
Replace NM_STATIC_ASSERT_EXPR() by NM_STATIC_ASSERT_EXPR_1() and
NM_STATIC_ASSERT_EXPR_VOID(). NM_STATIC_ASSERT_EXPR_VOID() can be
used as an expression that returns void (that is, a simple statement).
On the other hand, NM_STATIC_ASSERT_EXPR_1() itself retuns
a compile time constant of int value 1. The latter is useful, because
we can use the 1 to combine static assertions in expressions that
are themself compile time constants, like
#define STATIC_CHECK_AND_GET(cond, value) \
(NM_STATIC_ASSERT_EXPR_1(cond) ? (value) : (value))
This is itself a compile time constant if value is a compile
time constant. Also, it does the compile time check that "cond"
is true.
Usually, properties that are set to their default are not serialized on
D-Bus. That is, to_dbus_fcn() returns NULL.
In some cases, we explicitly want to always serialize the property. For
example, if we changed behavior and the libnm default value changed.
Then we want that the message on D-Bus is always clear about the used
value and not rely on the default value on the receiving side.
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.
For each property we have meta data in form of NMSettInfoProperty.
Each meta data also has a NMSettInfoProperty.property_type
(NMSettInfoPropertType).
The property type is supposed to define common behaviors for properties,
while the property meta data has individual properties. The idea is that
several properties can share the same property-type, and that
per-property meta data is part of NMSettInfoProperty.
The distinction is not very strong, but note that all remaining uses
of NMSettInfoPropertType.gprop_to_dbus_fcn were part of a property
type that was only used for one single property. That lack of
reusability hints to a wrong use.
Move gprop_to_dbus_fcn to the property meta data as a new field
NMSettInfoProperty.to_dbus_data.
Note that NMSettInfoPropertType.gprop_from_dbus_fcn still suffers from
the same problem. But the from-dbus side is not yet addressed.
For GBytes, GEnum, GFlags and others, we need special converters from the
default GObject properties to GVariant.
Previously, those were implemented by providing a special
gprop_to_dbus_fcn hook. But gprop_to_dbus_fcn should move
from NMSettInfoPropertType to NMSettInfoProperty, because it's
usually a per-property meta data, and not a per-property-type meta data.
The difference is whether the meta data can be shared between different
properties (of the same "type).
In these cases, this extra information is indeed part of the type.
We want to have a generic NM_SETT_INFO_PROPERT_TYPE_GPROP() property
(using _nm_setting_property_to_dbus_fcn_gprop()), but then we would like
to distinguish between special cases. So this was fine.
However, I find the approach of providing a gprop_to_dbus_fcn in this
case cumbersome. It makes it harder to understand what happens. Instead,
introduce a new "gprop_type" for the different types that
_nm_setting_property_to_dbus_fcn_gprop() can handle.
This new "gprop_type" is extra data of the property type, so
introduce a new field "typdata_to_dbus".
The advantage is that we use similar macros for initializing the
static structs like
const NMSettInfoPropertType nm_sett_info_propert_type_cloned_mac_address;
and the ad-hoc locations that use NM_SETT_INFO_PROPERT_TYPE().
The former exist for property types that are used more than once.
The latter exist for convenience, where a property type is implemented
at only one place.
Also, there are few direct references to _nm_setting_property_to_dbus_fcn_gprop().
all users use NM_SETT_INFO_PROPERT_TYPE_GPROP() or
NM_SETT_INFO_PROPERT_TYPE_GPROP_INIT().
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().
NMConfigData is immutable and with the previous commit are the strings
already cached internally. There is no need to clone it.
Of course, the callers must not assume that the string stays alive after
a config reload (SIGHUP), where the NMConfigData might change. So they
are not always alive, but long enough for all callers to avoid cloning
the string.
Previously, we would call g_key_file_get_string(), which requires
two hash lookups (one for the group and one for the key).
We can do better. Especially since NMConfigData is immutable, it's
simple to build a lookup index of the values we have and then do binary
search.
Note that we call nm_config_data_get_connection_default() and similar
API *a lot*, so this is measurable.
The buffer created here is only temporary to construct the property info
by _nm_setting_class_commit_full(). We can afford to allocate more than
necessary, if we thereby avoid several reallocations.
In presence of a IPv6 deprecated address and a non-deprecated one, the
latter will be used by kernel for new connections according to RFC
6724 section 5 (Source Address Selection). Prefer it also to lookup a
hostname via reverse DNS.
While at it, also prefer non-link-local addresses over link-local
ones.
Add a new flag to match deprecated addresses. An address is deprecated
when its preferred lifetime has expired but its valid lifetime has
not.
Address deprecation is one of the criteria for source address
selection in IPv6. For IPv4 the deprecation doesn't have any
real effect.
Note that this commit changes the behavior of
nm_ip_config_get_first_address(WITH_ADDRSTATE_NORMAL), since now
deprecated addresses are not returned. However this should not impact
existing callers since they either:
- request a IPv6 (WITH_ADDRTYPE_LINKLOCAL | WITH_ADDRSTATE_NORMAL)
address; IPv6 link-local addresses are supposed to have infinite
lifetimes;
or
- request a IPv6 (WITH_ADDRTYPE_NORMAL | WITH_ADDRSTATE__ANY)
address.
When determining the hostname, it is preferable to evaluate devices in
a predictable order to avoid that the hostname changes between
different boots.
The current order is based first on hostname priority, then on the
presence of a best default route, and then on activation order.
The activation order is not a very strong condition, as it is
basically useless for devices that are autoactivated at boot.
As we already prefer IPv4 over IPv6 within the same connection, also
prefer it when 2 connections have the same priority and the same
default route status, to achieve better predictability.
https://bugzilla.redhat.com/show_bug.cgi?id=1970335https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/merge_requests/895
We now have a cached list of NMSettingsConnection instances,
sorted by their autoconnect priority.
However, the sort order nm_settings_connection_cmp_autoconnect_priority()
depends on various properties of the connection:
- "connection.autoconnect" and "connection.autoconnect-priority"
- the timestamp
- "connection.uuid"
These properties almost never change, so it's a waste that every call
to nm_settings_get_connections_sorted_by_autoconnect_priority() needs
to check whether the sort order is still satisfied.
We can do better by tracking when the sort order might have been
destroyed and only check in those (much fewer) cases.
Note that we end up calling nm_settings_get_connections_sorted_by_autoconnect_priority()
a lot, so this makes a difference.
The GetSettings() call is not the only place where we convert a
NMConnection to D-Bus. However it is one of the most prominent ones
with a measurable performance overhead.
The connection seldom changes, so it makes sense to cache it.
Note that GetSettings() is the only caller that specifies an option,
thus it's the only caller that converts a NMConnection to variant
in this particular way. That means, other callers don't benefit from
this caching and we could not cache the variant in the NMConnection
instance itself, because those callers use different parameters.
Not very useful, but it seems nicer to read. They anyway can be
inlined. After all, naming and structure is important and the places
where we emit signals are important. By having well-named helper
functions, these places are easier to find and reason about.
Turns out, we call nm_settings_get_connection_clone() *a lot* with sort order
nm_settings_connection_cmp_autoconnect_priority_p_with_data().
As we cache the (differently sorted) list of connections, also cache
the presorted list. The only complication is that every time we still
need to check whether the list is still sorted, because it would be
more complicated to invalidate the list when an entry changes which
affects the sort order. Still, such a check is usually successful
and requires "only" N-1 comparisons.
