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44eb1adda9
Currently, our introspection data looks like this:
<node>
<interface name="org.freedesktop.DBus.Peer">
...
</interface>
<interface name="org.freedesktop.DBus.Introspectable">
...
</interface>
<interface name="org.freedesktop.DBus.Properties">
...
</interface>
<node name="org"/>
<node name="org/freedesktop"/>
<node name="org/freedesktop/login1"/>
<node name="org/freedesktop/login1/user"/>
<node name="org/freedesktop/login1/user/self"/>
<node name="org/freedesktop/login1/user/_1000"/>
<node name="org/freedesktop/login1/seat"/>
<node name="org/freedesktop/login1/seat/self"/>
<node name="org/freedesktop/login1/seat/seat0"/>
<node name="org/freedesktop/login1/session"/>
<node name="org/freedesktop/login1/session/self"/>
<node name="org/freedesktop/login1/session/c1"/>
</node>
(ordered alphabetically for better visibility)
This is grossly incorrect. The spec says that we're allowed to return
non-directed children, however, it does not allow us to return data
recursively in multiple parents. If we return "org", then we must not
return anything else that starts with "org/".
It is unclear, whether we can include child-nodes as a tree. Moreover, it
is usually not what the caller wants. Hence, this patch changes sd-bus to
never return introspection data recursively. Instead, only a single
child-layer is returned.
This patch relies on enumerators to never return hierarchies. If someone
registers an enumerator via sd_bus_add_enumerator, they better register
sub-enumerators if they support *TRUE* hierarchies. Each enumerator is
treated as a single layer and not filtered.
Enumerators are still allowed to return nested data. However, that data
is still required to be a single hierarchy. For instance, returning
"/org/foo" and "/com/bar" is fine, but including "/com" or "/org" in that
dataset is not.
This should be the default for enumerators and I see no reason to filter
in sd-bus. Moreover, filtering that data-set would require to sort the
strv by path and then do prefix-filtering. This is O(n log n), which
would be fine, but still better to avoid.
Fixes #664.
systemd - System and Service Manager
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