Names can fail to resolve in %m, not in %L when listening on port 445.

[Samba.git] / docs / manpages-3 / smb.conf.5.xml

<refentry id="smb.conf.5" xmlns:xi="http://www.w3.org/2003/XInclude"
                         xmlns:samba="http://www.samba.org/samba/DTD/samba-doc">
        
<refmeta>
        <refentrytitle>smb.conf</refentrytitle>
        <manvolnum>5</manvolnum>
</refmeta>


<refnamediv>
        <refname>smb.conf</refname>
        <refpurpose>The configuration file for the Samba suite</refpurpose>
</refnamediv>

<refsect1>
        <title>SYNOPSIS</title>

        <para>
        The <filename moreinfo="none">smb.conf</filename> file is a configuration  file for the Samba suite. <filename
        moreinfo="none">smb.conf</filename> contains  runtime configuration information for the Samba programs. The
        <filename moreinfo="none">smb.conf</filename> file is designed to be configured and  administered by the
        <citerefentry><refentrytitle>swat</refentrytitle> <manvolnum>8</manvolnum></citerefentry> program. The
        complete description of the file format and possible parameters held within are here for reference purposes.
        </para> 
</refsect1>

<refsect1 id="FILEFORMATSECT">
        <title>FILE FORMAT</title>

        <para>
        The file consists of sections and parameters. A section begins with the name of the section in square brackets
        and continues until the next section begins. Sections contain parameters of the form:
<screen>
<replaceable>name</replaceable> = <replaceable>value </replaceable>
</screen>
        </para>

        <para>
        The file is line-based - that is, each newline-terminated line represents either a comment, a section name or
        a parameter.
        </para>

        <para>Section and parameter names are not case sensitive.</para>

        <para>
        Only the first equals sign in a parameter is significant.  Whitespace before or after the first equals sign is
        discarded.  Leading, trailing and internal whitespace in section and parameter names is irrelevant. Leading
        and trailing whitespace in a parameter value is discarded. Internal whitespace within a parameter value is
        retained verbatim.
        </para>

        <para>
        Any line beginning with a semicolon (<quote>;</quote>) or a hash (<quote>#</quote>) 
        character is ignored, as are lines containing only whitespace.
        </para>

        <para>
        Any line ending in a <quote>\</quote> is continued on the next line in the customary UNIX fashion.
        </para>

        <para>
        The values following the equals sign in parameters are all either a string (no quotes needed) or a boolean,
        which may be given as yes/no, 0/1 or true/false. Case is not significant in boolean values, but is preserved
        in string values. Some items such as create masks are numeric.
        </para>

</refsect1>

<refsect1>
        <title>SECTION DESCRIPTIONS</title>

        <para>
        Each section in the configuration file (except for the [global] section) describes a shared resource (known as
        a <quote>share</quote>). The section name is the name of the shared resource and the parameters within the
        section define the shares attributes.
        </para>

        <para>
        There are three special sections, [global], [homes] and [printers], which are described under
        <emphasis>special sections</emphasis>. The following notes apply to ordinary section descriptions.
        </para>

        <para>
        A share consists of a directory to which access is being given plus a description of the access rights
        which are granted to the user of the service. Some housekeeping options are also specifiable.
        </para>
        
        <para>
        Sections are either file share services (used by the client as an extension of their native file systems)
        or printable services (used by the client to access print services on the host running the server).
        </para>
        
        <para>
        Sections may be designated <emphasis>guest</emphasis> services, in which case no password is required to
        access them. A specified UNIX <emphasis>guest account</emphasis> is used to define access privileges in this
        case.
        </para>

        <para>
        Sections other than guest services will require a password to access them. The client provides the
        username. As older clients only provide passwords and not usernames, you may specify a list of usernames to
        check against the password using the <literal>user =</literal> option in the share definition. For modern clients
        such as Windows 95/98/ME/NT/2000, this should not be necessary.
        </para> 

        <para>
        The access rights granted by the server are masked by the access rights granted to the specified or guest
        UNIX user by the host system. The server does not grant more access than the host system grants.
        </para>
        
        <para>
        The following sample section defines a file space share.  The user has write access to the path <filename
        moreinfo="none">/home/bar</filename>.  The share is accessed via the share name <literal>foo</literal>:
        </para>

<smbconfblock>
        <smbconfsection name="[foo]"/>
        <smbconfoption name="path">/home/bar</smbconfoption>
        <smbconfoption name="read only">read only = no</smbconfoption>
</smbconfblock>

        <para>
        The following sample section defines a printable share.  The share is read-only, but printable. That is,
        the only write access permitted is via calls to open, write to and close a spool file. The <emphasis>guest
        ok</emphasis> parameter means access will be permitted as the default guest user (specified elsewhere):
        </para>

<smbconfblock>
        <smbconfsection name="[aprinter]"/>
        <smbconfoption name="path">/usr/spool/public</smbconfoption>
        <smbconfoption name="read only">yes</smbconfoption>
        <smbconfoption name="printable">yes</smbconfoption>
        <smbconfoption name="guest ok">yes</smbconfoption>
</smbconfblock>

</refsect1>

<refsect1>
        <title>SPECIAL SECTIONS</title>
        
        <refsect2>
                <title>The [global] section</title>
                
                <para>
                Parameters in this section apply to the server as a whole, or are defaults for sections that do not
                specifically define certain items. See the notes under PARAMETERS for more information.
                </para>
        </refsect2>
        
        <refsect2 id="HOMESECT">
                <title>The [homes] section</title>
                
                <para>
                If a section called [homes] is included in the configuration file, services connecting clients
                to their home directories can be created on the fly by the server.
                </para>

                <para>
                When the connection request is made, the existing sections are scanned. If a match is found, it is
                used. If no match is found, the requested section name is treated as a username and looked up in the local
                password file. If the name exists and the correct password has been given, a share is created by cloning the
                [homes] section.
                </para>
                
                <para>
                Some modifications are then made to the newly created share:
                </para>
                
                <itemizedlist>
                        <listitem><para>
                        The share name is changed from homes to the located username.
                        </para></listitem>

                        <listitem><para>
                        If no path was given, the path is set to the user's home directory.
                        </para></listitem>
                </itemizedlist>

                <para>
                If you decide to use a <emphasis>path =</emphasis> line in your [homes] section, it may be useful 
                to use the %S macro. For example:
<screen>
<userinput moreinfo="none">path = /data/pchome/%S</userinput>
</screen>
                is useful if you have different home directories for your PCs than for UNIX access.
                </para>

                <para>
                This is a fast and simple way to give a large number of clients access to their home directories with a minimum 
                of fuss.
                </para>

                <para>
                A similar process occurs if the requested section name is <quote>homes</quote>, except that the share
                name is not changed to that of the requesting user. This method of using the [homes] section works well if
                different users share a client PC.
                </para>
                
                <para>
                The [homes] section can specify all the parameters a normal service section can specify, though some make more sense 
                than others. The following is a typical and suitable [homes] section:
                </para>

        <smbconfblock>
                <smbconfsection name="[homes]"/>
                <smbconfoption name="read only">no</smbconfoption>
        </smbconfblock>
        
                <para>
                An important point is that if guest access is specified in the [homes] section, all home directories will be 
                visible to all clients <emphasis>without a password</emphasis>.  In the very unlikely event that this is actually
                desirable, it is wise to also specify <emphasis>read only access</emphasis>.
                </para>

                <para>
                The <emphasis>browseable</emphasis> flag for auto home directories will be inherited from the global browseable 
                flag, not the [homes] browseable flag. This is useful as it means setting <emphasis>browseable = no</emphasis> in
                the [homes] section will hide the [homes] share but make any auto home directories visible.
                </para>
        </refsect2>

        <refsect2 id="PRINTERSSECT">
                <title>The [printers] section</title>
                
                <para>
                This section works like [homes], but for printers.
                </para>

                <para>
                If a [printers] section occurs in the configuration file, users are able to connect to any printer 
                specified in the local host's printcap file.
                </para>

                <para>
                When a connection request is made, the existing sections are scanned. If a match is found, it is used.
                If no match is found, but a [homes] section exists, it is used as described above. Otherwise, the requested
                section name is treated as a printer name and the appropriate printcap file is scanned to see if the requested
                section name is a valid printer share name. If a match is found, a new printer share is created by cloning the
                [printers] section.
                </para>

                <para>
                A few modifications are then made to the newly created share:
                </para>

                <itemizedlist>
                        <listitem><para>The share name is set to the located printer name</para></listitem>

                        <listitem><para>If no printer name was given, the printer name is set to the located printer name</para></listitem>

                        <listitem><para>If the share does not permit guest access and no username was given, the username is set
                                to the located printer name.</para></listitem>
                </itemizedlist>

                <para>
                The [printers] service MUST be printable - if you specify otherwise, the server will refuse 
                to load the configuration file.
                </para>
                
                <para>
                Typically the path specified is that of a world-writeable spool directory with the sticky bit set on 
                it. A typical [printers] entry looks like this:
                </para>

        <smbconfblock>
                <smbconfsection name="[printers]"/>
                <smbconfoption name="path">/usr/spool/public</smbconfoption>
                <smbconfoption name="guest ok">yes</smbconfoption>
                <smbconfoption name="printable">yes</smbconfoption>
        </smbconfblock>

                <para>
                All aliases given for a printer in the printcap file are legitimate printer names as far as the server is concerned. 
                If your printing subsystem doesn't work like that, you will have to set up a pseudo-printcap. This is a file
                consisting of one or more lines like this:
<screen>
alias|alias|alias|alias...    
</screen>
</para>

                <para>
                Each alias should be an acceptable printer name for your printing subsystem. In the [global] section,
                specify the new file as your printcap.  The server will only recognize names found in your pseudo-printcap,
                which of course can contain whatever aliases you like. The same technique could be used simply to limit access
                to a subset of your local printers.
                </para>

                <para>
                An alias, by the way, is defined as any component of the first entry of a printcap record. Records are separated by newlines,
                components (if there are more than one) are separated by vertical bar symbols (<literal>|</literal>).
                </para>
                
                <note><para>
                On SYSV systems which use lpstat to determine what printers are defined on the system you may be able to use
                <literal>printcap name = lpstat</literal> to automatically obtain a list of printers. See the
                <literal>printcap name</literal> option for more details.
                </para></note>
        </refsect2>
</refsect1>

<refsect1>
        <title>PARAMETERS</title>

        <para>Parameters define the specific attributes of sections.</para>

        <para>
        Some parameters are specific to the [global] section (e.g., <emphasis>security</emphasis>).  Some parameters
        are usable in all sections (e.g., <emphasis>create mask</emphasis>). All others are permissible only in normal
        sections. For the purposes of the following descriptions the [homes] and [printers] sections will be
        considered normal.  The letter <emphasis>G</emphasis> in parentheses indicates that a parameter is specific to
        the [global] section. The letter <emphasis>S</emphasis> indicates that a parameter can be specified in a
        service specific section. All <emphasis>S</emphasis> parameters can also be specified in the [global] section
        - in which case they will define the default behavior for all services.
        </para>

        <para>
        Parameters are arranged here in alphabetical order - this may not create best bedfellows, but at least you can
        find them! Where there are synonyms, the preferred synonym is described, others refer to the preferred
        synonym.
        </para>
</refsect1>

<refsect1>
        <title>VARIABLE SUBSTITUTIONS</title>

        <para>
        Many of the strings that are settable in the config file can take substitutions. For example the option
        <quote>path = /tmp/%u</quote> is interpreted as <quote>path = /tmp/john</quote> if the user connected with the
        username john.
        </para>

        <para>
        These substitutions are mostly noted in the descriptions below, but there are some general substitutions
        which apply whenever they might be relevant. These are:
        </para>

        <variablelist>
                <varlistentry>
                <term>%U</term>
                <listitem><para>session username (the username that the client wanted, not
                        necessarily the same as the one they got).</para></listitem>
                </varlistentry>
                
                <varlistentry>
                <term>%G</term>
                <listitem><para>primary group name of %U.</para></listitem>
                </varlistentry>

                <varlistentry>
                <term>%h</term>
                <listitem><para>the Internet hostname that Samba is running on.</para></listitem>
                </varlistentry>

                <varlistentry>
                <term>%m</term>
                <listitem><para>the NetBIOS name of the client machine (very useful).</para>

                        <para>This parameter is not available when Samba listens on port 445, as clients no longer
                        send this information. If you use this macro in an include statement on a domain that has
                        a Samba domain controller be sure to set in the [global] section <parameter>smb ports =
                        139</parameter>. This will cause Samba to not listen on port 445 and will permit include
                        functionality to function as it did with Samba 2.x.
                        </para></listitem>

                </varlistentry>
                
                <varlistentry>
                <term>%L</term>
                <listitem><para>the NetBIOS name of the server. This allows you to change your config based on what
                        the client calls you. Your server can have a <quote>dual personality</quote>.
                </para></listitem>
                </varlistentry>
                
                <varlistentry>
                <term>%M</term>
                <listitem><para>the Internet name of the client machine.
                </para></listitem>
                </varlistentry>
                
                <varlistentry>
                <term>%R</term>
                <listitem><para>the selected protocol level after protocol negotiation. It can be one of CORE, COREPLUS, 
                        LANMAN1, LANMAN2 or NT1.</para></listitem>
                </varlistentry>

                <varlistentry>
                <term>%d</term>
                <listitem><para>the process id of the current server
                        process.</para></listitem>
                </varlistentry>
                
                <varlistentry>
                <term>%a</term>
                <listitem><para>the architecture of the remote
                        machine.  It currently recognizes Samba (<constant>Samba</constant>), 
                        the Linux CIFS file system (<constant>CIFSFS</constant>), OS/2, (<constant>OS2</constant>),
                        Windows for Workgroups (<constant>WfWg</constant>), Windows 9x/ME 
                        (<constant>Win95</constant>), Windows NT (<constant>WinNT</constant>),
                        Windows 2000 (<constant>Win2K</constant>), Windows XP (<constant>WinXP</constant>),
                        and Windows 2003 (<constant>Win2K3</constant>).  Anything else will be known as 
                        <constant>UNKNOWN</constant>.</para> 
                </listitem>
                </varlistentry>
                
                <varlistentry>
                <term>%I</term>
                <listitem><para>the IP address of the client machine.</para>
                </listitem>
                </varlistentry>

                <varlistentry>
                <term>%i</term>
                <listitem><para>the local IP address to which a client connected.</para>
                </listitem>
                </varlistentry>

                <varlistentry>
                <term>%T</term>
                <listitem><para>the current date and time.</para></listitem>
                </varlistentry>

                <varlistentry>
                <term>%D</term>
                <listitem><para>name of the domain or workgroup of the current user.</para></listitem>
                </varlistentry>
                
                <varlistentry>
                <term>%$(<replaceable>envvar</replaceable>)</term>
                <listitem><para>the value of the environment variable
                <replaceable>envar</replaceable>.</para></listitem>
                </varlistentry>
        </variablelist>

        <para>
        The following substitutes apply only to some configuration options (only those that are
        used when a connection has been established):
        </para>

        <variablelist>
                <varlistentry>
                <term>%S</term>
                <listitem><para>the name of the current service, if any.</para>
                </listitem>
                </varlistentry>
        
                <varlistentry>
                <term>%P</term>
                <listitem><para>the root directory of the current service, if any.</para></listitem>
                </varlistentry>
        
                <varlistentry>
                <term>%u</term>
                <listitem><para>username of the current service, if any.</para>
                </listitem>
                </varlistentry>
        
                <varlistentry>
                <term>%g</term>
                <listitem><para>primary group name of %u.</para></listitem>
                </varlistentry>
        
                <varlistentry>
                <term>%H</term>
                <listitem><para>the home directory of the user given by %u.</para></listitem>
                </varlistentry>

                <varlistentry>
                <term>%N</term>
                <listitem><para>
                        the name of your NIS home directory server.  This is obtained from your NIS auto.map entry. 
                        If you have not compiled Samba with the <emphasis>--with-automount</emphasis> option, this
                        value will be the same as %L.</para></listitem>
                </varlistentry>
        
                <varlistentry>
                <term>%p</term>
                <listitem><para>
                        the path of the service's home directory, obtained from your NIS auto.map entry. The NIS
                        auto.map entry is split up as <literal>%N:%p</literal>.</para></listitem>
                </varlistentry>
        </variablelist>
        
        <para>
        There are some quite creative things that can be done with these substitutions and other
        <filename moreinfo="none">smb.conf</filename> options.
        </para>
</refsect1>

<refsect1 id="NAMEMANGLINGSECT">
        <title>NAME MANGLING</title>
        
        <para>
        Samba supports <literal>name mangling</literal> so that DOS and Windows clients can use files that don't
        conform to the 8.3 format. It can also be set to adjust the case of 8.3 format filenames.
        </para>

        <para>
        There are several options that control the way mangling is performed, and they are grouped here rather
        than listed separately. For the defaults look at the output of the testparm program.
        </para>

        <para>
        All of these options can be set separately for each service (or globally, of course).
        </para>

        <para>
        The options are:
        </para>
        
        <variablelist>
        
        <varlistentry>
                <term>case sensitive = yes/no/auto</term>
                <listitem><para>
                controls whether filenames are case sensitive. If they aren't, Samba must do a filename search and match on
                passed names. The default setting of auto allows clients that support case sensitive filenames (Linux CIFSVFS
                and smbclient 3.0.5 and above currently) to tell the Samba server on a per-packet basis that they wish to
                access the file system in a case-sensitive manner (to support UNIX case sensitive semantics). No Windows or
                DOS system supports case-sensitive filename so setting this option to auto is that same as setting it to no
                for them. Default <emphasis>auto</emphasis>.
                </para></listitem>
                </varlistentry> 

                <varlistentry>
                <term>default case = upper/lower</term>
                <listitem><para>
                controls what the default case is for new filenames. Default <emphasis>lower</emphasis>.
                </para></listitem>
                </varlistentry> 
        
                <varlistentry>
                <term>preserve case = yes/no</term>
                <listitem><para>
                controls whether new files are created with the case that the client passes, or if they are forced to be the 
                <literal>default</literal> case. Default <emphasis>yes</emphasis>.
                </para></listitem>
                </varlistentry> 

                <varlistentry>
                <term>short preserve case = yes/no</term>
                <listitem><para>
                controls if new files which conform to 8.3 syntax, that is all in upper case and of suitable length,
                are created upper case, or if they are forced to be the <literal>default</literal> case. This option can be
                used with <literal>preserve case = yes</literal> to permit long filenames to retain their case, while short
                names are lowercased. Default <emphasis>yes</emphasis>.
                </para></listitem>
                </varlistentry> 
        </variablelist>
        
        <para>
        By default, Samba 3.0 has the same semantics as a Windows NT server, in that it is case insensitive but case preserving.
        </para>
        
</refsect1>

<refsect1 id="VALIDATIONSECT">
        <title>NOTE ABOUT USERNAME/PASSWORD VALIDATION</title>

        <para>
        There are a number of ways in which a user can connect to a service. The server uses the following steps
        in determining if it will allow a connection to a specified service. If all the steps fail, the connection
        request is rejected.  However, if one of the steps succeeds, the following steps are not checked.
        </para>

        <para>
        If the service is marked <quote>guest only = yes</quote> and the server is running with share-level
        security (<quote>security = share</quote>, steps 1 to 5 are skipped.
        </para>


        <orderedlist continuation="restarts" inheritnum="ignore" numeration="arabic">
                <listitem><para>
                If the client has passed a username/password pair and that username/password pair is validated by the UNIX 
                system's password programs, the connection is made as that username. This includes the
                <literal>\\server\service%<replaceable>username</replaceable></literal> method of passing a username.
                </para></listitem>

                <listitem><para>
                If the client has previously registered a username with the system and now supplies a correct password for that 
                username, the connection is allowed.
                </para></listitem>
                
                <listitem><para>
                The client's NetBIOS name and any previously used usernames are checked against the supplied password. If 
                they match, the connection is allowed as the corresponding user.
                </para></listitem>
                
                <listitem><para>
                If the client has previously validated a username/password pair with the server and the client has passed 
                the validation token, that username is used.
                </para></listitem>

                <listitem><para>
                If a <literal>user = </literal> field is given in the <filename moreinfo="none">smb.conf</filename> file for the
                service and the client has supplied a password, and that password matches (according to the UNIX system's
                password checking) with one of the usernames from the <literal>user =</literal> field, the connection is made as
                the username in the <literal>user =</literal> line. If one of the usernames in the <literal>user =</literal> list
                begins with a <literal>@</literal>, that name expands to a list of names in the group of the same name.
                </para></listitem>

                <listitem><para>
                If the service is a guest service, a connection is made as the username given in the <literal>guest account
                =</literal> for the service, irrespective of the supplied password.
                </para></listitem>
        </orderedlist>

</refsect1>

<refsect1>
        <title>EXPLANATION OF EACH PARAMETER</title>
        
        <samba:parameterlist>
                <xi:include href="../smbdotconf/parameters.all.xml" parse="xml"/>
        </samba:parameterlist>

</refsect1>

<refsect1>
        <title>WARNINGS</title>
        
        <para>
        Although the configuration file permits service names to contain spaces, your client software may not.
        Spaces will be ignored in comparisons anyway, so it shouldn't be a problem - but be aware of the possibility.
        </para>

        <para>
        On a similar note, many clients - especially DOS clients - limit service names to eight characters.
        <citerefentry><refentrytitle>smbd</refentrytitle> <manvolnum>8</manvolnum></citerefentry> has no such
        limitation, but attempts to connect from such clients will fail if they truncate the service names.  For this
        reason you should probably keep your service names down to eight characters in length.
        </para>

        <para>
        Use of the <literal>[homes]</literal> and <literal>[printers]</literal> special sections make life 
        for an administrator easy, but the various combinations of default attributes can be tricky. Take extreme
        care when designing these sections. In particular, ensure that the permissions on spool directories are
        correct.
        </para>

</refsect1>

<refsect1>
        <title>VERSION</title>

        <para>This man page is correct for version 3.0 of the Samba suite.</para>
</refsect1>

<refsect1>
        <title>SEE ALSO</title>
        <para>
        <citerefentry><refentrytitle>samba</refentrytitle>
        <manvolnum>7</manvolnum></citerefentry>, <citerefentry><refentrytitle>smbpasswd</refentrytitle>
        <manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>swat</refentrytitle>
        <manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>smbd</refentrytitle>
        <manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>nmbd</refentrytitle>
        <manvolnum>8</manvolnum></citerefentry>, <citerefentry><refentrytitle>smbclient</refentrytitle>
        <manvolnum>1</manvolnum></citerefentry>, <citerefentry><refentrytitle>nmblookup</refentrytitle>
        <manvolnum>1</manvolnum></citerefentry>, <citerefentry><refentrytitle>testparm</refentrytitle>
        <manvolnum>1</manvolnum></citerefentry>, <citerefentry><refentrytitle>testprns</refentrytitle>
        <manvolnum>1</manvolnum></citerefentry>.</para>
</refsect1>

<refsect1>
        <title>AUTHOR</title>
        
        <para>
        The original Samba software and related utilities were created by Andrew Tridgell. Samba is now developed
        by the Samba Team as an Open Source project similar to the way the Linux kernel is developed.
        </para>
        
        <para>
        The original Samba man pages were written by Karl Auer. The man page sources were converted to YODL format (another 
        excellent piece of Open Source software, available at <ulink noescape="1" url="ftp://ftp.icce.rug.nl/pub/unix/">
        ftp://ftp.icce.rug.nl/pub/unix/</ulink>) and updated for the Samba 2.0 release by Jeremy Allison.  The conversion
        to DocBook for Samba 2.2 was done by Gerald Carter. The conversion to DocBook XML 4.2 for Samba 3.0 was done by
        Alexander Bokovoy.
        </para>
</refsect1>

</refentry>