Re: How to determine the license of D-Bus interface spec files (XML)?

[Simon McVittie]

The usual term of art for the D-Bus interface descriptions you're talking
about here is "introspection XML".

On Mon, 19 Mar 2018 at 16:09:02 +0800, Boyuan Yang wrote:
> * Vala source code files are generated from D-Bus interface spec files
> (XML format) using "vala-dbus-binding-tool" (exist in Debian Archive)
> * Some of XML spec files are generated using "dbus-send" tool (exist
> in Debian Archive)

dbus-send doesn't "generate" anything. It sends a message and prints
the reponse. Saying that dbus-send generates introspection XML is like
saying that wget generates the content of a web page.

Depending on the service you're using as the destination in your
dbus-send request, the introspection XML might either have been copied
from the source code into the service binary as a large string literal, or
constructed on-demand from data structures like GLib's GDBusInterfaceInfo.
I've seen both approaches used.

> * Other XML files are copied from Freedesktop.org website [4] and gnome-shell
> source code

> Now, here is the problem: contents in fd.o website has no licensing
> information. I asked (daniels) at irc #freedesktop and the person said
> that the status quo is "undefined" and it is not likely to change in
> near future.

If a particular freedesktop.org specification (in your case the File
Manager interface) doesn't have copyright/licensing information at its
upstream source, the only people who can give you that information are
the authors of that specification. The fact that a specification is
hosted on freedesktop.org isn't really any more significant here than
the fact that something else is hosted on Github.

> However, I'm not sure about the license of D-Bus interface itself as
> well as the XML file that describes such interface.

There is no single required license for D-Bus introspection XML, in the
same way that there is no single required license for C source code.

The org.freedesktop.DBus interface is defined by the D-Bus Specification
and its reference implementation "dbus", which are both available
under a dual-license: GPL-2.0 or any later version, or AFL-2.1 (see
/usr/share/doc/dbus/copyright); so the most restrictive terms that could
possibly be applied are that dual license.

The freedesktop.org File Manager interface is presumably defined by some
freedesktop.org specification: you know as much about this one as I do.

The org.gnome.Shell Screencast interface is presumably defined by GNOME
Shell and released under the same licensing terms as the rest of Shell.

> Anyway, it is an interface, not any concrete implementation.

I am not a lawyer, but I suspect that a bare interface description without
documentation, like
 and
,
might be considered to be sufficiently un-creative that it is not
protected by copyright: it's a purely functional description of what
is necessary to interoperate with a fd.o file manager.

An interface description that contains comments/documentation should
probably be treated like source code, though. Ideally the upstream
developers of GNOME Shell would put copyright/licensing information in
their introspection XML just like they should for any other source code.

> P.S. I'm asking this question looking for an answer to make sure that
> this package won't get rejected during the NEW process by ftp-masters
> due to licensing problems.

Only the ftp team can tell you whether they would accept or reject a
package and why. The debian-legal mailing list has no authority over
the ftp team.

smcv

How to determine the license of D-Bus interface spec files (XML)?

[Boyuan Yang]

[cc-me please; I am not on list]

Hi debian-legal list and Debian D-Bus maintainers,

Recently I encountered a package that has unclear license status and I
would like some help from you.

Please take a look at "peek" software[1]. Its packaging repo can be
found at [2]. Files in doubt are in [3].

Some quick facts:

* Vala source code files are generated from D-Bus interface spec files
(XML format) using "vala-dbus-binding-tool" (exist in Debian Archive)
* Some of XML spec files are generated using "dbus-send" tool (exist
in Debian Archive)
* Other XML files are copied from Freedesktop.org website [4] and gnome-shell
source code


Now, here is the problem: contents in fd.o website has no licensing
information. I asked (daniels) at irc #freedesktop and the person said
that the status quo is "undefined" and it is not likely to change in
near future.

However, I'm not sure about the license of D-Bus interface itself as
well as the XML file that describes such interface. Anyway, it is an
interface, not any concrete implementation. In fact, I can regenerate
the XML spec file included in [4] using "dbus-send" tool too with a
Debian system where dbus (daemon) is running.

With a GPL-3+ project like [1], what is the best practice to satisfy
Debian's requirement about packaging and license?


[1] https://github.com/phw/peek
[2] http://salsa.debian.org/hosiet-guest/peek
[3] https://github.com/phw/peek/tree/master/src/dbus
[4] https://www.freedesktop.org/wiki/Specifications/file-manager-interface/


P.S. I'm asking this question looking for an answer to make sure that
this package won't get rejected during the NEW process by ftp-masters
due to licensing problems.

--
Sincerely,
Boyuan Yang