<chapter id="VFS"> <chapterinfo> &author.jelmer; &author.jht; <author><firstname>Tim</firstname><surname>Potter</surname></author> <author><firstname>Simo</firstname><surname>Sorce</surname><contrib>original vfs_skel README</contrib></author> <author><firstname>Alexander</firstname><surname>Bokovoy</surname><contrib>original vfs_netatalk docs</contrib></author> <author><firstname>Stefan</firstname><surname>Metzmacher</surname><contrib>Update for multiple modules</contrib></author> </chapterinfo> <title>Stackable VFS modules</title> <sect1> <title>Features and Benefits</title> <para> Since Samba-3, there is support for stackable VFS(Virtual File System) modules. Samba passes each request to access the unix file system thru the loaded VFS modules. This chapter covers all the modules that come with the samba source and references to some external modules. </para> </sect1> <sect1> <title>Discussion</title> <para> If not supplied with your platform distribution binary Samba package you may have problems to compile these modules, as shared libraries are compiled and linked in different ways on different systems. They currently have been tested against GNU/Linux and IRIX. </para> <para> To use the VFS modules, create a share similar to the one below. The important parameter is the <smbconfoption><name>vfs objects</name></smbconfoption> parameter where you can list one or more VFS modules by name. For example, to log all access to files and put deleted files in a recycle bin: <smbconfexample> <title>smb.conf with VFS modules</title> <smbconfsection>[audit]</smbconfsection> <smbconfoption><name>comment</name><value>Audited /data directory</value></smbconfoption> <smbconfoption><name>path</name><value>/data</value></smbconfoption> <smbconfoption><name>vfs objects</name><value>audit recycle</value></smbconfoption> <smbconfoption><name>writeable</name><value>yes</value></smbconfoption> <smbconfoption><name>browseable</name><value>yes</value></smbconfoption> </smbconfexample> </para> <para> The modules are used in the order in which they are specified. </para> <para> Samba will attempt to load modules from the <emphasis>lib</emphasis> directory in the root directory of the samba installation (usually <filename>/usr/lib/samba/vfs</filename> or <filename>/usr/local/samba/lib/vfs </filename>). </para> <para> Some modules can be used twice for the same share. This can be done using a configuration similar to the one below. <smbconfexample> <title>smb.conf with multiple VFS modules</title> <smbconfsection>[test]</smbconfsection> <smbconfoption><name>comment</name><value>VFS TEST</value></smbconfoption> <smbconfoption><name>path</name><value>/data</value></smbconfoption> <smbconfoption><name>writeable</name><value>yes</value></smbconfoption> <smbconfoption><name>browseable</name><value>yes</value></smbconfoption> <smbconfoption><name>vfs objects</name><value>example:example1 example example:test</value></smbconfoption> <smbconfoption><name>example1: parameter</name><value>1</value></smbconfoption> <smbconfoption><name>example: parameter</name><value>5</value></smbconfoption> <smbconfoption><name>test: parameter</name><value>7</value></smbconfoption> </smbconfexample> </para> </sect1> <sect1> <title>Included modules</title> <sect2> <title>audit</title> <para> A simple module to audit file access to the syslog facility. The following operations are logged: <itemizedlist> <listitem><para>share</para></listitem> <listitem><para>connect/disconnect</para></listitem> <listitem><para>directory opens/create/remove</para></listitem> <listitem><para>file open/close/rename/unlink/chmod</para></listitem> </itemizedlist> </para> </sect2> <sect2> <title>extd_audit</title> <para> This module is identical with the <emphasis>audit</emphasis> module above except that it sends audit logs to both syslog as well as the smbd log file/s. The loglevel for this module is set in the smb.conf file. </para> <para> The logging information that will be written to the smbd log file is controlled by the <smbconfoption><name>log level</name></smbconfoption> parameter in &smb.conf;. The following information will be recorded: </para> <table frame="all"><title>Extended Auditing Log Information</title> <tgroup cols="2" align="center"> <thead> <row><entry align="center">Log Level</entry><entry>Log Details - File and Directory Operations</entry></row> </thead> <tbody> <row><entry align="center">0</entry><entry align="left">Creation / Deletion</entry></row> <row><entry align="center">1</entry><entry align="left">Create / Delete / Rename / Permission Changes</entry></row> <row><entry align="center">2</entry><entry align="left">Create / Delete / Rename / Perm Change / Open / Close</entry></row> </tbody> </tgroup> </table> </sect2> <sect2> <title>fake_perms</title> <para> This module was created to allow Roaming Profile files and directories to be set (on the Samba server under Unix) as read only. This module will if installed on the Profiles share will report to the client that the Profile files and directories are writable. This satisfies the client even though the files will never be overwritten as the client logs out or shuts down. </para> </sect2> <sect2> <title>recycle</title> <para> A recycle-bin like module. When used any unlink call will be intercepted and files moved to the recycle directory instead of being deleted. This gives the same effect as the "Recycle Bin" on Windows computers. </para> <para>Supported options: <variablelist> <varlistentry> <term>recycle:repository</term> <listitem><para>Relative path of the directory where deleted files should be moved to</para></listitem> </varlistentry> <varlistentry> <term>recycle:keeptree</term> <listitem><para>Specifies whether the directory structure should be kept or if the files in the directory that is being deleted should be kept seperately in the recycle bin. </para></listitem> </varlistentry> <varlistentry> <term>recycle:versions</term> <listitem><para>If this option is set, two files with the same name that are deleted will both be kept in the recycle bin. Newer deleted versions of a file will be called "Copy #x of <replaceable>filename</replaceable>".</para></listitem> </varlistentry> <varlistentry> <term>recycle:touch</term> <listitem><para>Specifies whether a file's access date should be touched when the file is moved to the recycle bin.</para></listitem> </varlistentry> <varlistentry> <term>recycle:maxsize</term> <listitem><para>Files that are larger than the number of bytes specified by this parameter will not be put into the recycle bin.</para></listitem> </varlistentry> <varlistentry> <term>recycle:exclude</term> <listitem><para>List of files that should not be put into the recycle bin when deleted, but deleted in the regular way.</para></listitem> </varlistentry> <varlistentry> <term>recycle:exclude_dir</term> <listitem><para>Contains a list of directories. When files from these directories are deleted, they are not put into the recycle bin, but deleted in the regular way. </para></listitem> </varlistentry> <varlistentry> <term>recycle:noversions</term> <listitem><para>Opposite of <parameter>recycle:versions</parameter>. If both options are specified, this one takes precedence.</para></listitem> </varlistentry> </variablelist> </para> </sect2> <sect2> <title>netatalk</title> <para> A netatalk module, that will ease co-existence of samba and netatalk file sharing services. </para> <para>Advantages compared to the old netatalk module: <itemizedlist> <listitem><para>it doesn't care about creating of .AppleDouble forks, just keeps them in sync</para></listitem> <listitem><para>if a share in &smb.conf; doesn't contain .AppleDouble item in hide or veto list, it will be added automatically</para></listitem> </itemizedlist> </para> </sect2> </sect1> <sect1> <title>VFS modules available elsewhere</title> <para> This section contains a listing of various other VFS modules that have been posted but don't currently reside in the Samba CVS tree for one reason or another (e.g. it is easy for the maintainer to have his or her own CVS tree). </para> <para> No statements about the stability or functionality of any module should be implied due to its presence here. </para> <sect2> <title>DatabaseFS</title> <para> URL: <ulink noescape="1" url="http://www.css.tayloru.edu/~elorimer/databasefs/index.php">http://www.css.tayloru.edu/~elorimer/databasefs/index.php</ulink> </para> <para>By <ulink url="mailto:elorimer@css.tayloru.edu">Eric Lorimer</ulink>.</para> <para> I have created a VFS module which implements a fairly complete read-only filesystem. It presents information from a database as a filesystem in a modular and generic way to allow different databases to be used (originally designed for organizing MP3s under directories such as "Artists," "Song Keywords," etc... I have since applied it to a student roster database very easily). The directory structure is stored in the database itself and the module makes no assumptions about the database structure beyond the table it requires to run. </para> <para> Any feedback would be appreciated: comments, suggestions, patches, etc... If nothing else, hopefully it might prove useful for someone else who wishes to create a virtual filesystem. </para> </sect2> <sect2> <title>vscan</title> <para>URL: <ulink noescape="1" url="http://www.openantivirus.org/">http://www.openantivirus.org/</ulink></para> <para> samba-vscan is a proof-of-concept module for Samba, which uses the VFS (virtual file system) features of Samba 2.2.x/3.0 alphaX. Of course, Samba has to be compiled with VFS support. samba-vscan supports various virus scanners and is maintained by Rainer Link. </para> </sect2> </sect1> </chapter>