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%include "default.mgp"
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The GNU GPL Revisited
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by
Harald Welte <laforge@hmw-consulting.de>
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The GNU GPL Revisited
Contents
Introduction
What is Copyrightable?
Terminology
Common FOSS Licenses
The GNU GPL Revisited
Complete Source Code
Derivative Works
Non-Public Modifications
GPL Violations
Thanks
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The GNU GPL Revisited
Introduction
Who is speaking to you?
an independent Free Software developer
who earns his living off Free Software since 1997
who is one of the authors of the Linux kernel firewall system called netfilter/iptables
who IS NOT A LAWYER, although this presentation is the result of dealing almost a year with lawyers on the subject of the GPL
Why is he speaking to you?
because he thinks there is too much confusion about copyright and free software licenses. Even Red Hat CEO Matt Szulik stated in an interview that RedHat puts investments into 'public domain' :(
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The GNU GPL Revisited
Disclaimer
Legal Disclaimer
All information presented here is provided on an as-is basis
There is no warranty for correctness of legal information
The author is not a lawyer
This does not comprise legal advise
The authors experience is limited to German copyright law
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%page
The GNU GPL Revisited
What is copyrightable?
The GNU GPL is a copyright license, and thus only covers copyrighted works
Not everything is copyrightable (German: Schoepfungshoehe)
Small bugfixes are not copyrightable (similar to typo-fixes in a book)
As soon as the programmer has a choice in the implementation, there is significant indication of a copyrightable work
Choice in algorithm, not in formal representation
Apparently, the level for copyrightable works is relatively low
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The GNU GPL Revisited
Terminology
Public Domain
concept where copyright holder abandons all rights
same legal status as works where author has died 70 years ago (German: Gemeinfreie Werke)
Freeware
object code, free of cost. No source code
Shareware
proprietary "Try and Buy" model for object code.
Cardware/Beerware/...
Freeware that encourages users to send payment in kind
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%page
The GNU GPL Revisited
Terminology
Free Software
source code freely distributed
must allow redistribution, modification, non-discriminatory use
mostly defined by Free Software Foundation
Open Source
source code freely distributed
must allow redistribution, modification, non-discriminatory use
defined in the "Open Source Definition" by OSI
The rest of this document will refer to Free and Open Source Software as FOSS.
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%page
The GNU GPL Revisited
Common FOSS licenses
Original BSD License
allows redistribution, modification
even allows proprietary extensions with no source code offer
all docs, advertisement materials have to mention copyright holder
Modified BSD License
same as "Original BSD License", but no copyright statements required in docs and advertisements
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%page
The GNU GPL Revisited
Common FOSS licenses
GPL (GNU General Public Liense)
allows redistribution, including modified works
obliges distributor to supply source code including all modifications
usage rights are revoked if license conditions not met
LGPL (GNU Library General Public License)
explicitly allows linking of proprietary applications
written as special case for libraries (such as glibc)
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%page
The GNU GPL Revisited
The GNU GPL Revisited
Revisiting the GNU General Public License
Regulates distribution of copyrighted code, not usage
Allows distribution of source code and modified source code
The license itself is mentioned
A copy of the license accompanies every copy
Allows distribution of binaries or modified binaries, if
The license itself is mentioned
A copy of the license accompanies every copy
The complete source code is either included with the copy made available to any 3rd party
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%page
The GNU GPL Revisited
Complete Source Code
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"... complete source code means all the source code for all modules it contains, plus any associated interface definition files, plus the scripts used to control compilation and installation of the executable."
Our interpretation of this is:
Source Code
Makefiles
Tools for generating the firmware binary from the source
(even if they are technically no 'scripts')
General Rule:
Intent of License is to enable user to run modified versions of the program. They need to be enabled to do so.
Result: Signing binaries and only accepting signed versions without providing a signature key is not acceptable!
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%page
The GNU GPL Revisited
Derivative Works
What is a derivative work?
Not dependent on any particular kind of technology (static/dynamic linking, dlopen, whatever)
Even while the modification can itself be a copyrightable work, the combination with GPL-licensed code is subject to GPL.
No precendent in Germany so far
As soon as code is written for a specific non-standard API (such as the iptables plugin API), there is significant indication for a derivative work
This position has been successfully enforced out-of-court with two Vendors so far (iptables modules/plugins).
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The GNU GPL Revisited
Derivative Works
Position of my lawyer:
In-kernel proprietary code (binary kernel modules) are hard to claim GPL compliant
Case-by-case analysis required, especially when drivers/filesystems are ported from other OS's.
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The GNU GPL Revisited
Collected Works
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"... it is not the intent .. to claim rights or contest your rights to work written entirely by you; rather, the intent is to exercise the right to control the distribution of derivative or collective works ..."
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"... mere aggregation of another work ... with the program on a volume of a storage or distribution medium does not bring the other work und the scope of this license"
GPL allows "mere aggregation"
like a general-porpose Linux distribution (SuSE, Red Hat, ...)
GPL disallows "collective works"
legal grey area
tends to depend a lot on jurisdiction
no precendent so far
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The GNU GPL Revisited
Non-Public modifications
Non-Public modifications
A common misconception is that if you develop code within a corporation, and the code never leaves this corporation, you don't have to ship the source code.
However, at least German law would count every distribution beyound a number of close colleague as distribution.
Therefore, if you don't go for '3a' and include the source code together with the binary, you have to distribute the source code to any third party.
Also, as soon as you hand code between two companies, or between a company and a consultant, the code has been distributed.
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The GNU GPL Revisited
GPL Violations
When do I violate the license
when one ore more of the obligations are not fulfilled
What risk do I take if I violate the license?
the GPL automatically revokes any usage right
any copyright holder can obtain a preliminary injunction banning distribution of the infringing product
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The GNU GPL Revisited
Thanks
Thanks to
KNF
for first bringing me in contact with linux in 1994
Astaro AG
for sponsoring most of my netfilter work
Free Software Foundation
for the GNU Project
for the GNU General Public License
Dr. Till Jaeger
for handling my legal cases
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The slides of this presentation are available at http://www.gnumonks.org/
Further reading:
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The netfilter homepage http://www.netfilter.org/
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The http://www.gpl-violations.org/ project
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