Bug 1123403

Description of problem:
When I work with network interfaces through D-bus using methods defined in org.fedoraproject.FirewallD1.zone I'm getting inconsistent results.

Some methods (queryInterface, getZoneOfInterface, changeZoneOfInterface, changeZone, addInterface) returns just false and empty string, but removeInterface returns UNKNOWN_INTERFACE error.

This is little bit inconsistent and I think, that non-existing interface should be treated the same way in all the methods if they are not known to firewalld (there should be some list of interfaces know to firewall and user shouldn't add new interface from nowhere using these methods).

This also opens the question, how should firewalld treat interfaces, which doesn't exist in system. Where are they bounded or what happens to them and the zones bounded to them?

To come up with some use-case, I can say, that someone will need to setup new interface, he will make a typo in interface name, all the configuration will go as expected but it will not work, because he wrote "ethl" instead of "eth1" for example.


Version-Release number of selected component (if applicable):
upstream git

How reproducible:
deterministic

Steps to Reproduce:
dbus-send --system --dest=org.fedoraproject.FirewallD1 --print-reply --type=method_call /org/fedoraproject/FirewallD1 org.fedoraproject.FirewallD1.zone.removeInterface string:"work" string:"my_ifc0"
> Error org.freedesktop.DBus.Python.dbus.exceptions.DBusException: UNKNOWN_INTERFACE: my_ifc0

dbus-send --system --dest=org.fedoraproject.FirewallD1 --print-reply --type=method_call /org/fedoraproject/FirewallD1 org.fedoraproject.FirewallD1.zone.queryInterface string:"work" string:"my_ifc0"
> method return sender=:1.1908 -> dest=:1.1911 reply_serial=2
>    boolean false

dbus-send --system --dest=org.fedoraproject.FirewallD1 --print-reply --type=method_call /org/fedoraproject/FirewallD1 org.fedoraproject.FirewallD1.zone.getZoneOfInterface string:"my_ifc0"
> method return sender=:1.1908 -> dest=:1.1912 reply_serial=2
>    string ""

dbus-send --system --dest=org.fedoraproject.FirewallD1 --print-reply --type=method_call /org/fedoraproject/FirewallD1 org.fedoraproject.FirewallD1.zone.addInterface string:"work" string:"my_ifc0"
> method return sender=:1.1983 -> dest=:1.1991 reply_serial=2
>    string "work"

dbus-send --system --dest=org.fedoraproject.FirewallD1 --print-reply --type=method_call /org/fedoraproject/FirewallD1 org.fedoraproject.FirewallD1.zone.changeZoneOfInterface string:"work" string:"my_ifc0"
> method return sender=:1.1983 -> dest=:1.1984 reply_serial=2
>    string "work"

Expected results:
Every mentioned method should fail with the same error as the first one.
or
Mention in documentation that this is also not checked nowhere?