hw-addr is a constuct-only property. We should not do complex stuff in the property
setter before the object is sufficiently initialized. For example, the logging
macros access nm_device_get_iface(), which might be unset at that early
point.
Instead, initialize hw_addr and hw_addr_len later, at the end of the constructor()
function.
Also, ensure that @hw_addr_len is zero iff @hw_addr is unset.
Also, ensure that we always log a message when changing/setting the
hardware address -- except when clearing it during unrealize. It's
implicit that unrealize clears the hardware address.
Also, give all related logging messages a "hw-addr:" prefix.
Accessing the platform cache might anytime yield unexpected results.
E.g. the link could be gone, or the ifindex could even be replaced
by a different interface (yes, that can happen when moving links
between network namespaces).
It's not clear how to handle such a case at runtime. It seems wrong to
me to just error out. Still, such case might happen under normal
conditions, so it's wrong to just warn and proceed.
When the entire NMSettingWired setting is missing, it should be treated
exactly the same as each property having the default/unset value.
Otherwise, adding a NMSettingWired setting only to set (say) MTU,
would result in different behavior. Although effectively the
"cloned-mac-address" shall be in both cases the same.
There was no leak here, because we would only call
nm_device_update_initial_hw_address() when @initial_hw_addr is unset.
However, still clear it to make it more robust against later changes.
_nm_utils_hwaddr_to_dbus() would serialize invalid hardware addresses
as "'cloned-mac-address': <@ay []>".
An empty array is treated the same as no hardware address set,
so we should not serialize it in the first place.
This is a change in behavior on how the connection is exported
on D-Bus, but it should not have any bad consequences.
We need this as we later want to deprecate the 'cloned-mac-address'
D-Bus field and overwrite it via a 'assigned-mac-address' field.
In this case, the "<@ay []>" is interfering. While it could be worked
around by treating an empty MAC address as "unset", fix it instead
and just not serialize it.
When modifying an existing ifcfg-rh file, we always want to enforce
the absense of a certain setting. That is done, by calling svSetValue()
with a value of NULL.
Same for writing MTU value.
When comparing settings, nm_setting_compare() performs a complicated
logic, which basically serializes each GObject property to a GVariant
for the D-Bus representation.
That is wrong for example for ipv4.addresses, which don't contain
address labels. That is, the GObject property is called "addresses",
but the D-Bus field "addresses" cannot encode every information
and thus comparison fails. Instead, it would have to look into
"address-data".
Traditionally, we have virtual functions like compare_property() per
NMSetting to do the comparison. That comparison is based on the GObject
properties. I think that is wrong, because we should have a generic
concept of what a property is, independent from GObject properties.
With libnm, we added NMSettingProperty, which indeed is such an
GObject independent representation to define properties.
However, it is not used thoroughly, instead compare_property() is a hack
of special cases, overloads from NMSettingProperty, overloads of
compare_property(), and default behavior based on GParamSpec.
This should be cleaned up.
For now, just hack it by handle the properties with the problems
explicitly.
The Network_ID for generating RFC 7217 stable privacy IPv6 addresses
is by default the UUID of the connection.
Alternatively, prefer "connection.stable-id" as Network_ID to generate
the stable addresses. This allows to configure a set of connections that
all use the same Network_ID for generating stable addresses.
Note that the stable-id and the UUID do no overlap, that is two
connections
[connection]
uuid=uuid1
stable-id=
and
[connection]
uuid=uuid2
stable-id=uuid1
generate distinct addresses.
This new property be used as token to generate stable-ids instead
of the connection's UUID.
Later, this will be used by ipv6.addr-gen-mode=stable-privacy,
ethernet.cloned-mac-address=stable, and wifi.cloned-mac-address=stable
setting. Those generate stable addresses based on the connection's
UUID, but allow to use the stable-id instead.
This allows multiple connections to generate the same addresses
-- on the same machine, because in the above cases a machine
dependant key is also hashed.
NetworkManager.conf already contains several per-device settings,
that is, settings that have a device-spec as argument.
main.ignore-carrier
main.no-auto-default
main.assume-ipv6ll-only
keyfile.unmanged-devices
Optimally, these settings should be moved to the new [device*]
section.
For now, only move main.ignore-carrier there. For the others
it may not make sense to do so:
- main.no-auto-default: is already merged with internal state
from /var/lib/NetworkManager/no-auto-default.state. While
NMConfig's write API would be fine to also persist and merge
the no-auto-default setting, we'd still have to read the old
file too. Thus, deprecating this setting gets quite cumbersome
to still handle the old state file.
Also, it seems a less useful setting to configure in the
global configuration aside setting main.no-auto-default=*.
- main.assume-ipv6ll-only: one day, I hope that we no longer
assume connections at all, and this setting becomes entirely
obsolete.
- keyfile.unmanged-devices: this sets NM_UNMANAGED_USER_SETTINGS,
which cannot be overruled via D-Bus. For a future device.managed
setting we want it it to be overwritable via D-Bus by an explicit
user action. Thus, a device.managed property should have a different
semantic, this should be more like a device.unmanaged-force setting,
which could be done.
Add a new [device*] section to NetworkManager.conf. This works similar
like the default connection settings in [connection*].
This will allow us to express per-device configuration in NetworkManager.conf
in our familar style.
Later, via NMConfig's write API it will be possible to make settings
accessible via D-Bus and persist them in NetworkManager-intern.conf.
This way, the user can both edit configuration snippets and modify
them via D-Bus, and also support installing default configuration
from the package.
In a way, a [device*] setting is similar to networkd's link files.
The match options is all encoded in the match-device specs.
One difference is, that the resulting setting can be merged together
by multiple section by partially overwriting them. This makes it
more flexible and allows for example to drop a configuration snippet
that only sets one property, while the rest can be merged from different
snippets.
