Discussion:
How to determine the license of D-Bus interface spec files (XML)?
(too old to reply)
Boyuan Yang
2018-03-19 08:09:02 UTC
Permalink
[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
Simon McVittie
2018-03-19 09:38:48 UTC
Permalink
The usual term of art for the D-Bus interface descriptions you're talking
about here is "introspection XML".
Post by Boyuan Yang
* 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.
Post by Boyuan Yang
* 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.
Post by Boyuan Yang
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.
Post by Boyuan Yang
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
<https://github.com/phw/peek/blob/master/src/dbus/org.freedesktop.DBus.xml> and
<https://github.com/phw/peek/blob/master/src/dbus/org.freedesktop.FileManager1.xml>,
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.
Post by Boyuan Yang
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

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