[amsat-bb] Possible Outernet GPL violation

Joseph Armbruster josepharmbruster at gmail.com
Wed Oct 12 18:18:33 UTC 2016


I'm not familiar with this code base or software specifically, but I
am curious, how did you determine it was linked?  Did you use a
platform tool, such as ldd or dumpbin or did you just grep the
baseline for 'librtlsdr" and it popped up?  There's a difference
between finding text in a baseline vs a lib being statically or
dynamically linked into it, which is why I ask.  I will assume you are
correct and it is being used, one way or another.

Because you received a copy of a derivative work containing software
that has GPL applied to it, then you are entitled to the source code
of the derivative work.  It should have also come with a copy of the
GPL, but if not, bygons.

Developers Are human and make mistakes, it would be interesting to
hear from the authors to determine what the story is.  If the
libraries that you referred to are not being used and could be
stripped out, that could eliminate the issue down the road or they
could just release the whole thing under GPL moving forward and be
done with it.

I'm interested in following this :-)

Joseph Armbruster

On Wed, Oct 12, 2016 at 5:28 AM, Dani EA4GPZ <daniel at destevez.net> wrote:
> Hi all,
> As some of you may know, I'm trying to build a GNUradio receiver for
> Outernet, partly by reverse engineering their binary-only code.
> While examining this code, I've noted that this code is using librtlsdr
> and libmirisdr, which are licenced under the GPLv2 or later (and not
> LGPL). It is my understanding that this forces the binary-only code to
> be released under a GPL-compatible licence.
> More info:
> http://pastebin.com/ENCYejn8
> Can someone with legal experience tell whether am I right in my
> interpretation of the licences?
> Also, does anyone have the contact information for Outernet? I tried to
> contact the user "foxbunny" in Github, who is the main contributor to
> the Github repos of Outernet. However, he no longer works at Outernet.
> I know that some of you are having fun with the Outernet receiver, and I
> don't want to discourage anyone from doing so. However, I think that it
> is in agreement with the Ham Radio spirit to be able to learn how the
> technology works. Currently, the key software pieces of the Outernet
> receiver are closed-source.
> Recently, only after some nontrivial reverse engineering effort I could
> figure out the scrambler they use. It turns out it's a scrambler
> algorithm I hadn't heard about before, so there I learnt something:
> https://twitter.com/ea4gpz/status/785586536225976320
> Also, I think that in particular librtlsdr (the code that makes RTL-SDR
> receivers work) has given hams uncountable hours of enjoyment with these
> low cost SDR receivers. Therefore, we should support the fact that this
> software is GPL and try to protect it from anyone who wishes to abuse
> its licence.
> I think that the Outernet project would benefit from releasing all their
> software under a free software (open source) licence, and I told that to
> Thane Richard from Outernet when he first announce the project on
> amsat-bb almost a year ago.
> 73,
> Dani EA4GPZ.
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