CIFS, Microsoft and the Samba Team
A recent document released by Microsoft has led to some concern within
the Samba community regarding patents and licensing. The Samba Team
wishes to reassure the Samba community that this document will not
have any impact on the use or further development of Samba.
The Microsoft
document is a license agreement attached to a technical document
which provides information regarding the CIFS protocol. The CIFS
protocol (also known as the SMB protocol) is the core protocol that
Samba implements to provide seamless filesharing interoperability with
Microsoft networking products.
The key concerns that have been raised over this document are:
- Whether the Samba Team needs access to this document for future
developments in Samba
- Whether the patents mentioned in the Microsoft license agreement
have any impact on current or future usage and development of Samba
- Whether the anti-GPL components of the Microsoft license will
change the use of the GNU General Public License for Samba
To reassure the Samba community each of these concerns will be
addressed.
Use of Microsoft CIFS documentation
The CIFS/SMB protocol has had a long and rocky history, particularly
with regard to documentation of the protocol details. The document
that Microsoft has recently released adds nothing to the already
published knowledge of the CIFS protocol. It is quite strange that
Microsoft has gone to such lengths in terms of unusual licensing terms
for information which is readily available in existing public
documentation.
For people interested in a more accurate and complete description of
the CIFS/SMB protocol the Samba Team recommends the recently released
SNIA
CIFS document, which has been developed through a process of
industry collaboration.
CIFS and Patents
In the text of the license agreement Microsoft mentions two specific
patents that relate to the CIFS/SMB protocol. The license grants a
royalty free license to these patents, but specifically excludes free
software distributed under the GNU General Public License from this
royalty free patent license.
Some people have incorrectly assumed that Samba must implement the
methods described in these patents. In fact, the methods described in
these patents are quite inappropriate for a Unix/POSIX CIFS
implementation such as Samba. It would not even be possible to
implement the methods described in these patents in a portable POSIX
application. Instead, Samba treats the SMBreadbraw and SMBwritebraw
protocol elements in the same way as all other elements of the
CIFS/SMB protocol. This means that as far as we are aware Samba is
completely unaffected by the existence of these patents.
We would like to also point out that these patents cover an obsolete
section of the CIFS/SMB protocol that Microsoft themselves have
abandoned in their own products long ago. Microsoft abandoned these
"raw" protocol operations in CIFS because their basic design is
fatally flawed.
Samba and the GNU General Public License
The GNU General Public License has proved to be a very successful
model for the development of Samba. While Microsoft labels the GPL as
"Intellectual Property Impairing" in their license document, it has in
fact proved to be a very successful vehicle for encouraging the
development of a high quality CIFS/SMB implementation. Far from
"impairing" intellectual property the Samba Team believes that the
distribution terms of the GNU GPL has provided an environment which
has encouraged a high degree of industry collaboration to the benefit
of both Samba users and the many successful companies that have built
a wide range of products on top of Samba technology.
The Samba Team fully intends to continue in the use of the GNU GPL to
foster innovation and the development of enterprise class file and
print serving solutions that seamlessly interoperate with Microsoft
networking products.