A clarification of the GNU GPL License boundary within the Samba
Virtual File System (VFS) layer.

Samba is licensed under the GNU GPL. All code committed to the Samba
project or creating a derived work must be either licensed under the
GNU GPL or a compatible license.

Samba has several plug-in interfaces where external code may be called
from Samba GNU GPL licensed code. The most important of these is the
Samba VFS layer.

Samba VFS modules are intimately connected by header files and API
definitions to the part of the Samba code that provides file services,
and as such, code that implements a plug-in Samba VFS module must be
licensed under the GNU GPL or a compatible license.

However, Samba VFS modules may themselves call third-party external
libraries that are not part of the Samba project and are externally
developed and maintained.

As long as these third-party external libraries do not use any of the
Samba internal structure, APIs or interface definitions created by the
Samba project that are licensed under the GNU GPL then it is the view
of the Samba Team that such third-party external libraries called from
Samba VFS modules are not part of the Samba code and cannot be
considered a derived work of Samba for the purposes of GNU GPL
licensing. Thus such libraries are not required to be under the GNU
GPL or a GNU GPL compatible license.