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ipfilter on GNU/Linux: Is It Finally Here? (Linux Journal)

Linux Journal takes a look at the latest release of ipfilter. "For the better part of a decade, users of FreeBSD, OpenBSD, NetBSD, Solaris and IRIX have used Darren Reed's ipfilter software to firewall networks and protect individual systems from network-based attacks. Now, with the release of ipfilter 4.1.1, GNU/Linux is moving into the fold as a supported platform."
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ipfilter on GNU/Linux: Is It Finally Here? (Linux Journal)

Posted May 28, 2004 17:40 UTC (Fri) by allesfresser (subscriber, #216) [Link]

Ironically, OpenBSD stopped using ipfilter a couple releases ago because of license difficulties or some other such kind of thing. They now use their own package (pf).

ipfilter on GNU/Linux: Is It Finally Here? (Linux Journal)

Posted May 28, 2004 19:17 UTC (Fri) by andre (guest, #11559) [Link]

which by the way is far better than ipfilter.

IPF license non-free

Posted May 30, 2004 1:04 UTC (Sun) by bignose (subscriber, #40) [Link]

Specifically, the license granted on the code did not allow redistribution of modified or derivative works (and the author "clarified" this explicitly, during the break with OpenBSD), and thus was not a free software license.

IPF license non-free: OpenBSD CVS log

Posted May 30, 2004 1:11 UTC (Sun) by bignose (subscriber, #40) [Link]

Here is the CVS log showing why IPF was removed from OpenBSD: http://www.openbsd.org/cgi-bin/cvsweb/src/sbin/ipf/Attic/ipf.c

IPF current code under free license

Posted May 30, 2004 1:29 UTC (Sun) by bignose (subscriber, #40) [Link]

While OpenBSD did remove the IPF code because the license was at that time non-free, the author appears to have updated the license in the interim. (OpenBSD still does not include IPF, and with PF working quite well, it likely will not do so in the future.)

The current IPF code (linked from the article) has a license that appears to this reader to be free software; specifically, the IPFILTER.LICENSE file says:

 * Redistribution and use, with or without modification, in source and binary
 * forms, are permitted provided that this notice is preserved in its entirety
 * and due credit is given to the original author and the contributors.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed. i.e. this code cannot simply be
 * copied, in part or in whole, and put under another distribution licence
 * [including the GNU Public Licence.]

The author seems to dislike the BSD license loophole (where the code can be redistributed under a different license), and has an unexplained hatred for the GNU licenses, even naming a non-existent license (the "GNU Public License"); but all these clauses appear to be free.

IPF current code under free license

Posted Jun 3, 2004 7:16 UTC (Thu) by Peter (guest, #1127) [Link]

The author seems to dislike the BSD license loophole

It's not a loophole - it's quite intentional.

Interesting how this license is viral, but without requiring disclosure of source. If everyone distributing the code is required to keep the terms permitting "Redistribution ... in source and binary forms", how is it possible for a recipient to exercise this right if the source is not necessarily provided? Is it so much of a stretch to assume that if I am required to give you the right to redistribute IPF in source and binary forms, when I give it to you, that this also implies that I have to give you the source to begin with?

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