vfs-module lincense

Alexander Bokovoy a.bokovoy at sam-solutions.net
Wed Feb 27 08:14:09 GMT 2002

On Wed, Feb 27, 2002 at 09:14:00AM -0600, Esh, Andrew wrote:
>    How does that apply to VFS modules that are dynamically linked, and
>    referred to in smb.conf via the "vfs object" tag? By including
>    dynamically linked libraries, this implies that Samba's license
>    controls that of libc, libcrypt, libnsl, and many others. I don't
>    believe it does.
>    Perhaps you are referring to the other type of VFS "module": One that
>    is linked directly into Samba as a .o file, in the same way smbd/vfs.o
>    is. I agree that such modules are controlled by Samba's license.
Please look at http://www.fsf.org/licenses/gpl-faq.html#GPLAndPlugins for
detailed description why VFS modules for Samba must be under GPL-compatible
license. It does not depend on type of linking, actually, but on usage
pattern. An excerpt from GNU GPL FAQ page:

  "If the program dynamically links plug-ins, and they make function calls to
each other and share data structures, we believe they form a single
program, so plug-ins must be treated as extensions to the main program.
This means they must be released under the GPL or a GPL-compatible free
software license."

Currently, VFS modules make calls to and share data with only one type of 
different code than they themselves -- it is default VFS hooks provided 
by smbd. But in near future (~ April) situation will change with cascaded 
VFS layer.

And even in current situation smbd does not call plugins directly, they
are integrated into it instead and their functions are being used as
direct replacements for internal smbd's ones. This hardly can be
classified as 'the program uses fork and exec to invoke plug-ins' or 'the
communication between them is limited to invoking the `main' function of
the plug-in with some options and waiting for it to return' as specified
on GNU GPL FAQ page for differently-licensed plugins for GPLed software.

>    -----Original Message-----
>    From: Andrew Bartlett [[1]mailto:abartlet at pcug.org.au]
>    Sent: Wednesday, February 27, 2002 5:17 AM
>    To: Sergey Akhapkin
>    Cc: samba-technical at samba.org
>    Subject: Re: vfs-module lincense
>    Sergey Akhapkin wrote:
>    >
>    > Hello All,
>    >
>    > I'd wrote vfs-module for our antivirus daemon. I've question about
>    > licence.
>    > Are sources of vfs-module must be open or not ?
>    > Are sources must be distributed under GPL (if must be open) ?
>    > Can we distribute it not under GPL ?
>    All VFS modules *MUST* be distributed under the GPL.  All code that is
>    linked to Samba *must* be under distributable under the same licence
>    as
>    samba itself.
>    That being said, you are free to also distribute it under a more
>    liberal
>    licence (the LGPL for example) or another licence *and* the GPL (at
>    the
>    user's option).
>    Andrew Bartlett
>    --
>    Andrew Bartlett                                 abartlet at pcug.org.au
>    Manager, Authentication Subsystems, Samba Team  abartlet at samba.org
>    Student Network Administrator, Hawker College   abartlet at hawkerc.net
>    [2]http://samba.org     [3]http://build.samba.org
>    [4]http://hawkerc.net
> References
>    1. mailto:abartlet at pcug.org.au
>    2. http://samba.org/
>    3. http://build.samba.org/
>    4. http://hawkerc.net/

/ Alexander Bokovoy
Software architect and analyst             // SaM-Solutions Ltd.
The eagle may soar, but the weasel never gets sucked into a jet engine.

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