New VFS Module: linktrans
gerdts at bellsouth.net
Tue Aug 13 14:40:01 GMT 2002
I have written a new VFS module that translates symbolic links to MS DFS
links. You can get it at
What does it really do?
When a symbolic link to a directory is encountered, a mapping of
UNIX Directories to share names is consulted. If a match is found,
readlink() translates the standard UNIX symbolic link format into
the format normally expected by the DFS code. This causes a
redirect to be sent to the SMB client.
The code is smart enough to recognize symbolic links that point to
someplace other than just the root of a share. That is, if you have
A symbolic link to /projects/d1/someproject/somepart will redirect
the client to \\projserv\d1\someproject\somepart
Suppose you have an environment where users were encouraged to just
create symbolic links to get to areas that were not shared out via
Samba. You are now not happy with the mess that exists because
people may be using the "wrong" server (samba ends up acting as a
CIFS <-> NFS gateway), permissions that you intend to force are not
being forced, or access restrictions that you intend to have in
place are being bypassed.
With this module you can transition from promiscuous use of symbolic
links to using the option "follow symlinks = no" relatively
painlessly. Or at least that is the theory.
Build samba as you normally would. Be sure to use --with-msdfs as
one of your configure options.
Copy vfs-linktrans.c to samba-2.2.5/examples/VFS/linktrans.c
Edit samba-2.2.5/examples/VFS/Makefile.in. Add linktrans.so to the
In samba-2.2.5/examples/VFS, run ./configure, then make.
Copy linktrans.so to a lib directory somewhere. Presumably
/usr/local/samba/linktrans.so would be a could choice.
Edit /usr/local/samba/lib/smb.conf. Add "host msdfs = yes" to the
global section. Add "msdfs root = yes" and "vfs object =
/usr/local/lib/samba/linktrans.so" to each share that you want to
try this out on.
Create the file /etc/linktrans.map (defined in the .c file) with
lines that perform the lowest level mapping. For example, if all
symbolic links to /project/d1 should really go to \\projserv\d1, add
a line like "/project/d1 projserv\d1".
Reboot the Windows client that will connect to this share.
Does it really work?
As is said in the copyright notice at the top, there is no
warranty. It has, however, worked for me in a test environment
using Solaris servers and a Windows 2000 client. I have not yet
used it with multiple clients at once, nor have I put it on any
Comments, suggestions for improvement, and patches are welcome.
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