Another Netfilter GPL enforcement
[Editor's note: the following article was sent to us by Harald Welte, the leader of the Netfilter project.]
Two weeks ago you might have read about the netfilter/iptables project having resolved a GPL infringement case by a German networking gear vendor called Allnet. Today, the netfilter/iptables project made a similar announcement. The major difference: This time it's not about some unknown German company, but a large international hardware vendor: Fujitsu Siemens Computers (http://www.fujitsu-siemens.com).
So you might ask yourself: Why is there a sudden rise in pushing for GPL enforcement by the netfilter/iptables project? The remainder of this article will try to give you an answer from the project's point of view.
Everything started with the (in)famous Linksys WRT54G case. First postings about this issue are dating back to 7 June 2003 (http://lwn.net/Articles/35713/). Shortly thereafter, an FSF-led alliance for making Linksys comply to the GPL was formed. Since Linksys used netfilter/iptables to implement packet filtering and NAT on their device, the netfilter core team was invited to join that alliance. Initially this seemed like great idea. The head of the netfilter core team joined that alliance and provided information about how netfilter/iptables code was used. Even one of our GPL-licensed libraries had been linked into a proprietary, binary-only library.
Two months after first contact between the FSF-led alliance and Linksys, they finally published some code. This was just some random kernel source, and utterly incomplete (see http://lwn.net/Articles/51399/ and http://lwn.net/Articles/53140/). Despite a statement by the Cisco legal director about their world-class leading GPL compliance, it took them four months to provide a full source code release. To my knowledge, no compensation was paid, and none of the previous customers had been informed about their rights and obligations under the GPL.
The result is clear: The 'soft pressure' way of pushing for license compliance doesn't work. In fact, it encourages vendors to violate the GPL in the first place. They don't lose anything by not complying with the license. First, they release an infringing product. Second, somebody has to find out that they use GPL licensed code. Then, one of the original authors has to push for license compliance. The vendor would then further delay that issue for any time he wishes, and in the end he finally makes a source code release. But by having not lost anything in this strategy, why would he even bother complying with the GPL next time?
Meanwhile, more and more embedded networking devices like WLAN access points or DSL routers turned out to use netfilter/iptables without complying with the GPL license terms. Dissatisfied with the FSF way of GPL enforcement, the netfilter core team decided to take legal action against Allnet GmbH in Germany. We were prepared to apply for a preliminary injunction banning them from further sale of their devices.
Luckily, Allnet replied immediately to the warning notice, and they were very interested in resolving this issue out-of-court. Our main goal was and is to make people comply with the the GPL license terms. It is not in our intent to harass commercial users of netfilter/iptables, or to try to squeeze money out of them. All we're asking for is license compliance. If those vendors were using some proprietary licensed code, they would also have to comply with its license. Why should they allowed to behave different in case of the GPL?
Allnet understood and even agreed to inform all prior commercial buyers of the respective products. In addition, they show their support for free software by making donations to respected charities in the free software world.
Encouraged by this first settlement, we decided to go after every single infringing use of netfilter/iptables code we are aware of. From your author's point of view, this is the only way of raising conciousness about free software licensing in corporate management.
Fujitsu-Siemens was next on the list, and resolved in an equally friendly way.
Many more are pending, stay tuned.
