<html> <body bgcolor="#ffffff"> <img src="samba2_xs.gif" border="0" alt=" " height="100" width="76" hspace="10" align="left" /> <h1 class="head0">Chapter 5. Unix Clients</h1> <p><a name="INDEX-1"/>In <a href="ch03.html">Chapter 3</a> we showed you how to configure Windows systems to access shared resources on both Windows and Samba servers. This has probably opened up a whole new world of computing for you—one in which you have to run to a Windows system every time you want to copy a file between Unix and Windows! In this chapter, we will show you the "other side"—how to access SMB shares from your favorite Unix system.</p> <p>You can access SMB resources from Unix in three ways, depending on your version of Unix. A program included with the Samba distribution called <em class="emphasis">smbclient</em><a name="INDEX-2"/> can be used to connect with a share on the network in a manner similar to using <em class="emphasis">ftp</em> when transferring files to or from an FTP site.</p> <p>If your system is running Linux, you can use the <a name="INDEX-3"/>smbfs filesystem to mount SMB shares right onto your Linux filesystem, just as you would mount a disk partition or NFS filesystem. The SMB shares can then be accessed and manipulated by all programs running on the Linux system: command shells, desktop GUI interfaces, and application software.</p> <p>On some BSD-based systems, including Mac OS X, a pair of utilities named <em class="emphasis">smbutil</em> <a name="INDEX-4"/>and <em class="emphasis">mount_smbfs</em> <a name="INDEX-5"/>can be used to query SMB servers and mount shares.</p> <p>For other Unix variants, <em class="emphasis">smbsh</em><a name="INDEX-6"/> can be run to enable common shell commands such as <em class="emphasis">cd</em>, <em class="emphasis">ls</em>, <em class="emphasis">mv, wc</em>, and <em class="emphasis">grep</em> to access and manipulate files and directories on SMB shares. This effectively extends the reach of the Unix shell and utilities beyond the Unix filesystem and into the SMB network.</p> <p>All the Unix clients can access shares offered by either Windows systems or Samba servers. We have already shown you how to set up a share on a Samba server and could use that as an example to work with. But it's much more fun to use the Unix clients with shares served by Windows systems. So before we start covering the Unix clients in detail, we will take a quick detour and show you how to set up file shares on both Windows 95/98/Me and Windows NT/2000/XP systems.</p> <div class="sect1"><a name="samba2-CHP-5-SECT-1"/> <h2 class="head1">Sharing Files on Windows 95/98/Me</h2> <p>When <a name="INDEX-7"/><a name="INDEX-8"/>sharing files on Windows 95/98/Me, you can authenticate users in two different ways. <a name="INDEX-9"/><a name="INDEX-10"/>Share-level security is the default and is easy to use. However, it is not as secure and can require users to type in passwords when connecting to shares. User-level security offers a better security model and can be used if you have either a Samba or Windows NT/2000 server on your network performing user authentication.</p> <p>To configure the type of access control for your system, open the Control Panel, double-click the Network icon, then click the Access Control tab. You should see the dialog box shown in <a href="ch05.html#samba2-CHP-5-FIG-1">Figure 5-1</a>.</p> <div class="figure"><a name="samba2-CHP-5-FIG-1"/><img src="figs/sam2_0501.gif"/></div><h4 class="head4">Figure 5-1. The Access Control tab of the Windows 98 Network Control Panel window</h4> <p>Click the "Share-level access control" or "User-level access control" radio button, depending on which you want to use. When using user-level access control, you will also need to fill in the name of your workgroup or Windows NT domain. Reboot as requested.</p> <p>To share a folder, right-click the folder's icon and select Sharing . . . . This will open the Sharing tab of the folder's Properties dialog box. Click the "Shared As:" radio button, and fill in a name for the share (which defaults to the folder's name) and a description, which will be visible to client users. If you don't want the share to be visible in the Network Neighborhood view of other Windows clients, pick a name for the share that ends in a dollar sign (<tt class="literal">$</tt>).</p> <p><a href="ch05.html#samba2-CHP-5-FIG-2">Figure 5-2</a> shows what the Sharing tab of the folder's Properties dialog box will look like when using share-level security. The security settings are very simple. You can select a radio button for read-only access or full (read/write) access, or have the user's permissions (either read-only or read/write) depend on which password they use. In accordance with which you select, you will be asked to assign either or both of the read-only and full-access passwords for the share.</p> <div class="figure"><a name="samba2-CHP-5-FIG-2"/><img src="figs/sam2_0502.gif"/></div><h4 class="head4">Figure 5-2. The Sharing tab of the folder's Properties dialog, with share-level security</h4> <p>If your system is configured with user-level security, the Sharing tab of the folder's Properties dialog box will look like <a href="ch05.html#samba2-CHP-5-FIG-3">Figure 5-3</a>. As you can see, we've created a share named "DATA", and used the Add . . . button to create permissions that allow read-only access for all domain users and read/write (full access) for <tt class="literal">jay</tt>.</p> <div class="figure"><a name="samba2-CHP-5-FIG-3"/><img src="figs/sam2_0503.gif"/></div><h4 class="head4">Figure 5-3. The Sharing tab of the folder Properties dialog, with user-level security</h4> <p>When you are done specifying your settings for the share, click on the OK button, and the share will become available to users on network clients. Unless you chose a share name ending in a dollar sign, you can see it in the Network Neighborhood or My Network Places of Windows clients on the network. You can also now use the Unix clients described in this chapter to connect to the share.</p> </div> <div class="sect1"><a name="samba2-CHP-5-SECT-2"/> <h2 class="head1">Sharing Files on Windows NT/2000/XP</h2> <p>To create a file share on <a name="INDEX-11"/><a name="INDEX-12"/><a name="INDEX-13"/><a name="INDEX-14"/>Windows NT/2000/XP, you first must log in to the system as any member of the Administrators, Power Users, or Server Operators groups. Right-click the icon of a folder you wish to share, and click Sharing . . . in the pop-up menu. The Sharing tab of the folder's Properties dialog box will appear, as shown in <a href="ch05.html#samba2-CHP-5-FIG-4">Figure 5-4</a>. Click the "Share this folder" radio button.</p> <div class="figure"><a name="samba2-CHP-5-FIG-4"/><img src="figs/sam2_0504.gif"/></div><h4 class="head4">Figure 5-4. The Sharing tab of the folder's Properties dialog on Windows 2000</h4> <p>Share name: will default to the name of the folder, and you can change it if you want. One reason you might want to use a different name for the share is to make the share not appear in browse lists (as displayed by the Network Neighborhood, for example). This can be done by using a share name ending in a dollar sign (<tt class="literal">$</tt>). You can also add a description of the share in the Comment: text area. The description will appear to users of network clients and can help them understand the contents of the share.</p> <p><a name="INDEX-15"/><a name="INDEX-16"/><a name="INDEX-17"/><a name="INDEX-18"/><a name="INDEX-19"/>By clicking the Permissions button, you can set permissions for the share on a user-by-user basis. This is equivalent to the user-level security of Windows 95/98/Me file sharing. On Windows NT/2000/XP, Microsoft recommends that share permissions be set to allow full access by everyone, with the permissions controlled on a file-by-file basis using filesystem access control lists (<a name="INDEX-20"/>ACLs). The actual permissions given to network clients are a combination of the share permissions and file access permissions. To edit the ACL for the folder, click the Security tab. For more information on ACLs, see <a href="ch08.html#samba2-CHP-8-SECT-3">Section 8.3</a> in <a href="ch08.html">Chapter 8</a>.</p> <p>If you want, you can limit the number of users who can concurrently connect to the share using the "User limit:" radio button. The New Share button allows you to create multiple file shares for the same folder, each having its own name, comment, user limit, and other parameters.</p> <p>When you are done, click the OK button, and the folder will be accessible from clients on the network.</p> </div> <div class="sect1"><a name="samba2-CHP-5-SECT-3"/> <h2 class="head1">smbclient</h2> <p>The Samba Team supplies <em class="emphasis">smbclient</em><a name="INDEX-21"/> as a basic part of the Samba suite. At first, it might seem to be a primitive interface to the SMB network, but <em class="emphasis">smbclient</em> is actually a versatile tool. It can be used for browsing shares on servers, testing configurations, debugging, accessing shared printers, backing up shared data, and automating administrative tasks in shell scripts. And unlike <tt class="literal">smbfs</tt><a name="INDEX-22"/><a name="INDEX-23"/><a name="INDEX-24"/> and <em class="emphasis">smbsh</em>, <em class="emphasis">smbclient</em> works on all Unix variants that support Samba.</p> <p>In this chapter we'll focus mostly on running <em class="emphasis">smbclient</em> as an interactive shell, using its <em class="emphasis">ftp</em>-like commands to access shared directories on the network. Using <em class="emphasis">smbclient</em> to access printers and perform backups will be covered in <a href="ch10.html">Chapter 10</a>.</p> <p>A complete reference to <em class="emphasis">smbclient</em> is found in <a href="appc.html">Appendix C</a>.</p> <div class="sect2"><a name="samba2-CHP-5-SECT-3.1"/> <h3 class="head2">Listing Services</h3> <p><a name="INDEX-25"/>The <em class="emphasis">-L</em> option can be used with <em class="emphasis">smbclient</em> to list the resources on a single computer. Assuming the Samba server is configured to take the role of the master browser, we can obtain a list of the computers in the domain or workgroup like this:</p> <blockquote><pre class="code">$ <tt class="userinput"><b>smbclient -L toltec</b></tt> added interface ip=172.16.1.1 bcast=172.16.1.255 nmask=255.255.255.0 Password: Domain=[METRAN] OS=[Unix] Server=[Samba 2.2.5] Sharename Type Comment --------- ---- ------- test Disk For testing only, please IPC$ IPC IPC Service (Samba 2.2.5) ADMIN$ Disk IPC Service (Samba 2.2.5) Server Comment --------- ------- MAYA Windows 98 MIXTEC Samba 2.2.5 TOLTEC Samba 2.2.5 ZAPOTEC Workgroup Master --------- ------- METRAN TOLTEC</pre></blockquote> <p>In the column labeled "Server", <tt class="literal">maya</tt>, <tt class="literal">mixtec</tt>, and <tt class="literal">zapotec</tt> are shown along with toltec, the Samba server. The services on <tt class="literal">toltec</tt> are listed under "Sharename". The IPC$ and ADMIN$ shares are standard Windows services that are used for network communication and administrative purposes, and <em class="filename">test</em> is the directory we added as a share in <a href="ch02.html">Chapter 2</a>.</p> <p>Now that we know the names of computers in the domain, we can list services on any of those computers. For example, here is how we would list the services offered by <tt class="literal">maya</tt>, a Windows 98 workstation:</p> <blockquote><pre class="code">$ <tt class="userinput"><b>smbclient -L maya</b></tt> added interface ip=172.16.1.1 bcast=172.16.1.255 nmask=255.255.255.0 Password: Sharename Type Comment --------- ---- ------- PRINTER$ Disk HP Printer HP 932C on Maya D Disk D: on Maya E Disk E: on Maya ADMIN$ Disk IPC$ IPC Remote Inter Process Communication Server Comment --------- ------- Workgroup Master --------- -------</pre></blockquote> <p>A shared printer is attached to <tt class="literal">maya</tt>, so we see the PRINTER$ administrative service, along with the HP share for the printer itself. Also on <tt class="literal">maya</tt> are the D and E shares, which allow access across the network to <tt class="literal">maya</tt>'s D: and E: drives. It is normal for the Server and Workgroup sections to be empty when listing services on a Windows client.</p> </div> <div class="sect2"><a name="samba2-CHP-5-SECT-3.2"/> <h3 class="head2">Authenticating with smbclient</h3> <p><a name="INDEX-26"/>As with any other SMB client, <em class="emphasis">smbclient</em> needs to supply a username and password if it is authenticating in a domain environment or if it is contacting a Samba server that is set up with user-level security. In a workgroup environment, it will at least need a password to use when connecting with a password-protected resource.</p> <p>By default, <em class="emphasis">smbclient</em> uses the username of the user who runs it and then prompts for a password. If you are using <em class="emphasis">smbclient</em> a lot, you might tire of entering your password every time.</p> <p><em class="emphasis">smbclient</em> supports some alternate methods of entering a username and password. The password can be entered on the command line, like this:</p> <blockquote><pre class="code">$ <tt class="userinput"><b>smbclient //maya/e jayspassword</b></tt></pre></blockquote> <p>Or both the username and password can be supplied by using the <em class="emphasis">-U</em> option, including the username and password separated by a percent (<tt class="literal">%</tt>) character:</p> <blockquote><pre class="code">$ <tt class="userinput"><b>smbclient //maya/e -U kelly%kellyspassword</b></tt></pre></blockquote> <p>This method is useful if you are logged in to the system under an account that is not Samba-enabled or you are testing your configuration to see how it treats another user. With either method, you can avoid having to enter the username and/or password each time you run <em class="emphasis">smbclient</em> by creating an alias for the command or creating a shell function or shell script. For example, with the <em class="emphasis">bash</em> shell, it is possible to define a function like this:</p> <blockquote><pre class="code">smbcl( ) { smbclient $* -U jay%jayspassword }</pre></blockquote> <p>Adding the definition to the shell's startup script (which would be <em class="filename">~/.bash_profile</em> for <em class="emphasis">bash</em>) would result in the definition affecting all subsequent shell invocations.</p> <p>Another method that can be used to supply both the username and password is to set the USER and <a name="INDEX-27"/><a name="INDEX-28"/>PASSWD environment variables. Either set the USER environment variable using the <em class="replaceable">username</em>%<em class="replaceable">password</em> format, or set the USER environment variable to the username, and set PASSWD to the user's password.</p> <p>It is also possible to create a credentials file containing the username on the first line and the password on the second line, like this:</p> <blockquote><pre class="code">username = jay password = jayspassword</pre></blockquote> <p>Then, <em class="emphasis">smbclient</em> is run using the <em class="emphasis">-A</em> option to specify the name of the file:</p> <blockquote><pre class="code">$ <tt class="userinput"><b>smbclient //maya/e -A ~/.smbpw</b></tt></pre></blockquote> <a name="samba2-CHP-5-NOTE-120"/><blockquote class="note"><h4 class="objtitle">NOTE</h4> <p>Of the methods we described in this section, the only one that is really secure is the default method of allowing <em class="emphasis">smbclient</em><a name="INDEX-29"/> to prompt for the password and typing in the password without echoing.</p> <p>If security is a concern, you definitely should avoid providing your password on the command line because it is very easy for "shoulder surfers" to obtain, as well as anyone who looks through your shell's command history.</p> <p>If you keep your Samba password in a credentials file, shell startup file, or shell script, make sure the file's permissions prohibit other users from reading or writing it. (Use an octal permissions mode of 0600.) Security experts never keep passwords in files owned by nonroot users or accessible by anyone other than the superuser. As part of their security policy, some organizations do not permit passwords to be stored in files, so you might want to check first before using this method.</p> <p>The authentication method that uses the USER and PASSWD environment variables isn't any more secure. Environment variables are usually set either on the command line or in one or more of the shell's startup files, so this method suffers from the same weaknesses we've just discussed. In addition, any program run by the user has access to the shell's environment variables, making a Trojan horse attack on the PASSWD variable really easy!</p> </blockquote> </div> <div class="sect2"><a name="samba2-CHP-5-SECT-3.3"/> <h3 class="head2">An Interactive smbclient Session</h3> <p><a name="INDEX-30"/>A common use for <em class="emphasis">smbclient</em> is to use it as an <em class="emphasis">ftp</em>-like shell to access SMB resources on the network. To begin a session, <em class="emphasis">smbclient</em> must be provided with the UNC of a resource (which you can find using the <em class="emphasis">-L</em> option) on the command line, like this:</p> <blockquote><pre class="code">$ <tt class="userinput"><b>smbclient //maya/e</b></tt> added interface ip=172.16.1.3 bcast=172.16.1.255 nmask=255.255.255.0 Password: smb: \></pre></blockquote> <p>Forward slashes are accepted by <em class="emphasis">smbclient</em> for the share's UNC, which makes entering the UNC on the command line easier. Backslashes can also be used, but they must be quoted or escaped, and it is somewhat more difficult to type '<tt class="literal">\\maya\e</tt>' or <tt class="literal">\\\\maya\\e</tt>. After connecting to the share, <em class="emphasis">smbclient</em> displays the <tt class="literal">smb: \></tt> prompt, waiting for a command to be entered. Commands are similar to those with which you might be familiar in <em class="emphasis">ftp</em> and are also somewhat similar to Unix shell commands. To get a list of <em class="emphasis">smbclient</em><a name="INDEX-31"/> commands, use the <em class="emphasis">help</em> command:</p> <blockquote><pre class="code">smb: \> <tt class="userinput"><b>help</b></tt> ls dir du lcd cd pwd get mget put mput rename more mask del open rm mkdir md rmdir rd prompt recurse translate lowercase print printmode queue cancel quit q exit newer archive tar blocksize tarmode setmode help ? history !</pre></blockquote> <p>Some commands in the previous list are synonyms for other commands. For example, the <em class="emphasis">?</em> command is a synonym for <em class="emphasis">help</em>. You can give this command the name of another command as an argument to get a concise reminder of what the command does and how to use it:</p> <blockquote><pre class="code">smb: \> <tt class="userinput"><b>? ls</b></tt> HELP ls: <mask> list the contents of the current directory</pre></blockquote> <p>The term <tt class="literal"><mask></tt> refers to a file-matching pattern as commonly found in Unix shells and utilities. For example:</p> <blockquote><pre class="code">smb: \> <tt class="userinput"><b>ls *doc</b></tt> ms-ProfPol-wp.doc A 131 Tue Dec 18 09:12:34 2002 smbclient.doc A 33969 Mon Dec 10 20:22:24 2002 smbmount.doc A 7759 Mon Dec 10 20:20:00 2002 48590 blocks of size 524288. 40443 blocks available</pre></blockquote> <p>lists all files ending in "doc" in the current directory on the remote system. In the listing, the leftmost column shows the filename. Moving left to right, we see the file's MS-DOS attributes, then its size, and the time it was last modified.</p> <p>As with any other Unix utility, <em class="emphasis">smbclient</em> has a working directory on the local host. It also has another current directory on the remote SMB share. With <em class="citetitle">smbclient</em>, the <em class="emphasis">cd</em> command is used to move around on the remote system:</p> <blockquote><pre class="code">smb: \> <tt class="userinput"><b>cd trans </b></tt> smb: \trans\></pre></blockquote> <p>Notice how the prompt changes to reflect the new current working directory. To change your current directory on the local system, use the <em class="emphasis">lcd</em> command:</p> <blockquote><pre class="code">smb: \trans\> <tt class="userinput"><b>lcd /u/snd</b></tt> the local directory is now /u/snd</pre></blockquote> <p>Most of <em class="emphasis">smbclient</em>'s commands are for performing operations on remote files and directories. There is no command for listing the contents of the local directory. However, <em class="emphasis">smbclient</em> allows a shell escape. Any command preceded by an exclamation point (<tt class="literal">!</tt>) is interpreted as a shell command and is run in a subshell on the local system. For example:</p> <blockquote><pre class="code">smb: \trans\> <tt class="userinput"><b>! ls -l</b></tt> total 16 drwxrwxr-x 2 jay jay 4096 Jan 10 14:46 dr220-fet drwxrwxr-x 2 jay jay 4096 Sep 22 12:16 dr220-tube -rw-rw-r-- 1 jay jay 131 Jan 10 02:22 readme.txt drwxrwxr-x 7 jay jay 4096 Jan 10 02:19 xl1</pre></blockquote> <p>lists the contents of <em class="filename">/u/snd</em>. By using <em class="emphasis">smbclient</em>'s commands to operate on the remote system—and shell-escaped commands to operate on the local system—it is possible to manipulate data on both systems without having to exit <em class="emphasis">smbclient</em> or open another shell window.</p> <p><a name="INDEX-32"/><a name="INDEX-33"/>File transfer is performed using the <em class="emphasis">get</em> and <em class="emphasis">put</em><a name="INDEX-34"/><a name="INDEX-35"/> commands. The <em class="emphasis">get</em> command transfers a single file from the remote to the local system, and the <em class="emphasis">put</em> command copies a file from the local to the remote system. For example, the following command copies the file <em class="filename">readme.txt</em> to the SMB share:</p> <blockquote><pre class="code">smb: \trans\> <tt class="userinput"><b>put readme.txt</b></tt> putting file readme.txt as \trans\readme.txt (127.9 kb/s) (average 10.7 kb/s)</pre></blockquote> <a name="samba2-CHP-5-NOTE-121"/><blockquote class="note"><h4 class="objtitle">NOTE</h4> <p>Unlike <em class="emphasis">ftp</em>, <em class="emphasis">smbclient</em> does not have <em class="emphasis">ascii</em> and <em class="emphasis">binary</em> commands to set the type of the file that is being transferred. Before transferring a text file from a Unix system to a Windows or Macintosh system, you might want to use the GNU <em class="emphasis">unix2dos</em><a name="INDEX-36"/> command to reformat newlines in the file to work with the carriage return linefeed (CRLF) standard:</p> <blockquote><pre class="code">$ <tt class="userinput"><b>unix2dos text_file >text_file.txt</b></tt></pre></blockquote> <p>and then transfer the CRLF-formatted version. After transferring a text file from a Windows or Macintosh system to Unix, you can use the GNU <em class="emphasis">dos2unix</em><a name="INDEX-37"/> command to perform the inverse operation:</p> <blockquote><pre class="code">$ <tt class="userinput"><b>dos2unix text_file.txt >text_file</b></tt></pre></blockquote> </blockquote> <p>To transfer more than one file with a single command, you can use the <em class="emphasis">mget</em><a name="INDEX-38"/><a name="INDEX-39"/> and <em class="emphasis">mput</em> commands, which accept a list of filenames in the command line. The list can be provided by typing in the filenames on the command line separated by spaces, or the group of files can be specified with a pattern as one would use in Unix shell commands. The command:</p> <blockquote><pre class="code">smb: \trans\> <tt class="userinput"><b>mget plain/*</b></tt></pre></blockquote> <p>copies all the files in the directory <em class="filename">plain</em> on the SMB share to the current directory on the local system. By default, <em class="emphasis">smbclient</em> prompts for each file, asking if you want to copy it:</p> <blockquote><pre class="code">smb: \trans\> <tt class="userinput"><b>mget plain/*</b></tt> Get file tomm.wav? n Get file toml.wav? n Get file tomh.wav? n Get file snare.wav? n Get file rim.wav? n Get file handclap.wav? n Get file bassdrum.wav? n</pre></blockquote> <p>If you are sure you want to copy all the files, you can turn off prompting with the <em class="emphasis">prompt</em> command, like this:</p> <blockquote><pre class="code">smb: \trans\> <tt class="userinput"><b>prompt</b></tt> prompting is now off</pre></blockquote> <p>By default, if you specify the name of a directory, <em class="emphasis">smbclient</em> will not copy the contents of the directory. To transfer the entire contents of directories listed in the <em class="emphasis">mput</em> or <em class="emphasis">mget</em> command, you must first use the <em class="emphasis">recurse</em> command:</p> <blockquote><pre class="code">smb: \trans\> <tt class="userinput"><b>recurse</b></tt> directory recursion is now on</pre></blockquote> <p>After setting things up with the <em class="emphasis">prompt</em><a name="INDEX-40"/><a name="INDEX-41"/> and <em class="emphasis">recurse</em> commands, we can copy a directory like this:</p> <blockquote><pre class="code">smb: \trans\> <tt class="userinput"><b>mget acc</b></tt> getting file tomm.wav of size 55494 as tomm.wav (2580.6 kb/s) (average 2087.3 kb/s) getting file toml.wav of size 57220 as toml.wav (2660.9 kb/s) (average 2167.6 kb/s) getting file tomh.wav of size 55936 as tomh.wav (2601.2 kb/s) (average 2220.8 kb/s) getting file snare.wav of size 22132 as snare.wav (1200.7 kb/s) (average 2123.7 kb/s) getting file rim.wav of size 8314 as rim.wav (1623.8 kb/s) (average 2110.8 kb/s) getting file handclap.wav of size 14180 as handclap.wav (1978.2 kb/s) (average 2106.2 kb/s) getting file bassdrum.wav of size 6950 as bassdrum.wav (2262.3 kb/s) (average 2108.5 kb/s)</pre></blockquote> <p><a name="INDEX-42"/>Directory recursion applies to all commands, so if an <em class="emphasis">ls</em> command is used while directory recursion is on, all files in the directory tree are listed. To turn directory recursion off again, simply re-enter the command. At the same time, you might also wish to toggle prompting back to its initial state:</p> <blockquote><pre class="code">smb: \trans\> <tt class="userinput"><b>recurse</b></tt> directory recursion is now off smb: \trans\> <tt class="userinput"><b>prompt</b></tt> prompting is now on</pre></blockquote> <p>There are other <em class="emphasis">smbclient</em> commands that you might find useful. The <em class="emphasis">mkdir</em> command can be used to create a directory; <em class="emphasis">rmdir</em> removes a directory; <em class="emphasis">rm</em> deletes a file; and <em class="emphasis">rename</em> changes a file's name. These behave very similarly to their Unix shell counterparts. <a href="appc.html">Appendix C</a> contains a complete reference to <em class="emphasis">smbclient</em> and its command set.</p> <p>To exit <em class="emphasis">smbclient</em>, use the <em class="emphasis">exit</em> or <em class="emphasis">quit</em> command:</p> <a name="INDEX-43"/><blockquote><pre class="code">smb: \trans\> <tt class="userinput"><b>quit </b></tt></pre></blockquote> </div> <div class="sect2"><a name="samba2-CHP-5-SECT-3.4"/> <h3 class="head2">Programming with smbclient</h3> <p><a name="INDEX-44"/>The <em class="emphasis">-c</em> option <em class="emphasis">of smbclient</em> allows a list of commands to be passed on the command line. To copy the file <em class="filename">\\maya\e\trans\readme.txt</em> to <em class="filename">/u/snd/readme.txt</em>, we might use the command:</p> <blockquote><pre class="code">$ <tt class="userinput"><b>smbclient //maya/e -c "lcd /u/snd; cd trans; get readme.txt" -A ~/.smbpw</b></tt></pre></blockquote> <p>Everything that <em class="emphasis">smbclient</em> needs to know to perform the operation has been specified in the command. There is no interactive session, so a command such as this can be placed inside a shell script or a program in some other programming language.</p> <p>By using <em class="emphasis">smbclient</em> in this manner, it is possible to create customized commands using shell functions, scripts or aliases. For example, suppose we wanted a command to print a short listing of files in a shared directory, showing just the names of the files. Using a <em class="emphasis">bash</em> function, we could define a command <em class="emphasis">smbls</em> as follows:</p> <blockquote><pre class="code">smbls( ) { share=`echo $1 | cut -d '/' -f '1-4'` dir=`echo $1 | cut -d '/' -f '5-'` smbclient $share -c "cd $dir; ls" -A ~/.smbpw | \ grep "^ " | cut -d ' ' -f 3 - | sort }</pre></blockquote> <p>After defining this function, we can use <em class="emphasis">smbls</em> like this:</p> <blockquote><pre class="code">$ <tt class="userinput"><b>smbls //maya/e</b></tt> CD-images lectures ms-ProfPol-wp.doc profile-map readme.txt RECYCLED smbclient.doc smbmount.doc smbsh.txt trans $ <tt class="userinput"><b>smbls //maya/e/lectures</b></tt> . .. lecture1.mp3 lecture2.mp3 lecture3.mp3 lecture4.mp3 lecture5.mp3 lecture6.mp3 lecture7.mp3 lecture8.mp3 lecture9.mp3</pre></blockquote> <p>Another use for <em class="emphasis">smbclient</em> in scripts is performing administrative tasks. Suppose a group of users on Windows clients are sharing a set of files as part of a project on which they are working. Instead of expecting them to coordinate making daily backups, we could write a script that copies the share to the Samba server and run the script nightly as a cron job. The directory on the Samba server could be shared as well, allowing any of the users to retrieve a backup file on their own, without having to bother an administrator.</p> </div> <div class="sect2"><a name="samba2-CHP-5-SECT-3.5"/> <h3 class="head2">Backups with smbclient</h3> <p>A major use of <em class="emphasis">smbclient</em><a name="INDEX-45"/><a name="INDEX-46"/> is to create and restore backups of SMB file shares. The backup files <em class="emphasis">smbclient</em> writes are in tar format, making them easy to work with and portable among all Unix versions. Using <em class="emphasis">smbclient</em> on a Unix server to run network backups can result in a more centralized and easily managed solution for providing data integrity because both SMB shares and NFS filesystems can be backed up on the same system.</p> <p>You can use <em class="emphasis">smbclient</em> to perform backups in two ways. When backing up an entire share, the simplest method is to use the <em class="emphasis">-Tc</em> option on the command line:</p> <blockquote><pre class="code"># <tt class="userinput"><b>smbclient //maya/e -A samba-domain-pw -Tc >maya-e.tar</b></tt></pre></blockquote> <p>This will create a tar archive of the <em class="filename">\\maya\e</em> share in the file <em class="filename">maya-e.tar</em>. By using the <em class="emphasis">-D</em> option, it is possible to back up a directory in the share, rather than the whole share:</p> <blockquote><pre class="code"># <tt class="userinput"><b>smbclient //maya/e -A samba-domain-pw -D trans -Tc >maya-e.tar</b></tt></pre></blockquote> <p>This causes <em class="emphasis">smbclient</em> to change its working directory to the <em class="filename">trans</em> directory of the <em class="filename">\\maya\e</em> share before starting the backup. It is also possible to use <em class="emphasis">smbclient</em>'s <em class="emphasis">tar</em> command in interactive mode, like this:</p> <blockquote><pre class="code"># <tt class="userinput"><b>smbclient //maya/e </b></tt> added interface ip=172.16.1.3 bcast=172.16.1.255 nmask=255.255.255.0 Password: smb: \> <tt class="userinput"><b>cd trans</b></tt> smb: \trans\> <tt class="userinput"><b>tarmode full hidden system quiet</b></tt> smb: \trans\> <tt class="userinput"><b>tar c maya-e-trans.tar</b></tt></pre></blockquote> <p>With the previous code, only the <em class="emphasis">trans</em> subdirectory in the <em class="emphasis">\\maya\e</em> share will be backed up, using the settings specified in the <em class="emphasis">tarmode</em> command. To have this type of backup run automatically from a script, use the <em class="emphasis">-c</em> option:</p> <blockquote><pre class="code"># <tt class="userinput"><b>smbclient //maya/e -A samba-domain-pw -c "cd trans; tarmode full hidden \</b></tt> <tt class="userinput"><b> system quiet; tar >maya-e-trans.tar"</b></tt></pre></blockquote> <p>Using either the <em class="emphasis">-T</em> command-line option or <em class="emphasis">smbclient</em>'s <em class="emphasis">tar</em> command, additional options can be supplied. It is necessary to specify either the <em class="emphasis">c</em> option to create a backup archive or the <em class="emphasis">x</em> option to extract (restore) one.<a name="FNPTR-1"/><a href="#FOOTNOTE-1">[1]</a> </p> <p>The other options can be appended to the option string and are explained in the section on <em class="emphasis">smbclient</em> in <a href="appc.html">Appendix C</a>. They allow you to create incremental backups, specify which files to include or exclude from the backup, and specify a few other miscellaneous settings. For example, suppose we wish to create an incremental backup of a share and reset the archive bit on the files to set things up for the next incremental backup. Instead of using the interactive commands:</p> <blockquote><pre class="code">smb: \> <tt class="userinput"><b>tarmode inc reset quiet</b></tt> smb: \> <tt class="userinput"><b>tar c backup.tar</b></tt></pre></blockquote> <p>we could either use the interactive command:</p> <blockquote><pre class="code">smb: \> <tt class="userinput"><b>tar cgaq backup.tar</b></tt></pre></blockquote> <p>or specify the <em class="emphasis">-Tcgaq</em> option on the <em class="emphasis">smbclient</em> command line.</p> <p>Your best strategy for using <em class="emphasis">smbclient</em> for network backups depends on your local configuration. If you have only a few Windows systems sharing a small amount of data, you might create a script containing <em class="emphasis">smbclient -Tc</em> commands to back up each share to a separate tar file, placing the files in a directory that is included with regular backups of the Unix system. If you have huge SMB shares on your network, you might prefer to write the backup directly to a tape drive. You can do this with <em class="emphasis">smbclient</em> just as you would with a Unix <em class="emphasis">tar</em> command:</p> <blockquote><pre class="code"># <tt class="userinput"><b>smbclient //maya/d -A samba-domain-pw -Tc >/dev/tape</b></tt></pre></blockquote> <p>After you have become more familiar with <em class="emphasis">smbclient</em> and have an automated backup system in place, you might find that using Samba has dramatically decreased your anxiety regarding the integrity of your network's data. The authors of this book are experienced Unix system administrators, and we highly recommend having a backup strategy that has been carefully planned, implemented, and most importantly, <em class="emphasis">tested and known to work as it is supposed to</em>.</p> </div> </div> <div class="sect1"><a name="samba2-CHP-5-SECT-4"/> <h2 class="head1">smbfs</h2> <p>On Linux, the <a name="INDEX-47"/>smbfs filesystem can be used to mount SMB shares onto the Linux filesystem in a manner similar to mounting disk partitions on NFS filesystems. The result is so transparent that users on the Linux system might never be aware that they are accessing files through a Windows or Samba server. Files and directories appear as any other files or directories on the local Linux system, although there are a few differences in behavior relating to ownership and permissions.<a name="FNPTR-2"/><a href="#FOOTNOTE-2">[2]</a></p> <p>Although smbfs is based on the Samba code, it is not itself part of the Samba distribution. Instead, it is included with Linux as a standard part of the Linux filesystem support.</p> <p>The <em class="emphasis">smbmount</em> and <em class="emphasis">smbmnt</em><a name="INDEX-48"/> programs are part of the Samba distribution and are needed on the client to mount smbfs filesystems. Samba must be compiled with the <tt class="literal">--with-smbmount</tt> configure option to make sure these programs are compiled. They refer to <em class="filename">smb.conf</em> for information they need regarding the local system and network configuration, so you will need a working <em class="filename">smb.conf</em><a name="INDEX-49"/><a name="INDEX-50"/> file on the system, even if it is not acting as a Samba server. <a name="INDEX-51"/><a name="INDEX-52"/><a name="INDEX-53"/></p> <div class="sect2"><a name="samba2-CHP-5-SECT-4.1"/> <h3 class="head2">Mounting an smbfs Filesystem</h3> <p>The <em class="emphasis">smbmount</em><a name="INDEX-54"/> command is used to mount an smbfs filesystem into the Linux filesystem. The basic usage is:</p> <blockquote><pre class="code"># <tt class="userinput"><b>smbmount </b></tt><em class="replaceable">Share-UNC mount-point</em><tt class="userinput"><b> -o </b></tt><em class="replaceable">options</em></pre></blockquote> <p>Replace <em class="replaceable">Share-UNC</em> with the UNC for the SMB share, and <em class="replaceable">mount-point</em> with the full path to the directory in the Linux filesystem to use as the mount point. The <em class="replaceable">options</em> argument is used to set the exact manner in which the share is mounted. Let's look at an example of a <em class="emphasis">smbmount</em> command:</p> <blockquote><pre class="code"># <tt class="userinput"><b>smbmount //maya/e /smb/e \</b></tt> <tt class="userinput"><b> -o "credentials=/home/jay/.smbpw,uid=jay,gid=jay,fmask=664,dmask=775"</b></tt></pre></blockquote> <p>Here we are mounting share <em class="filename">\\maya\e</em> from a Windows 98 system on the mount point <em class="filename">/smb/e</em> on the Linux system.</p> <a name="samba2-CHP-5-NOTE-122"/><blockquote class="note"><h4 class="objtitle">NOTE</h4> <p>If your Linux kernel doesn't include smbfs support, you will get the error message:</p> <blockquote><pre class="code">ERROR: smbfs filesystem not supported by the kernel</pre></blockquote> <p>In this case, you must configure and compile a new kernel to include support for smbfs. When smbfs is installed, and an SMB share is mounted, you can run the command:</p> <blockquote><pre class="code">$ <tt class="userinput"><b>cat /proc/filesystems</b></tt></pre></blockquote> <p>and see a line that looks like:</p> <blockquote><pre class="code">nodev smbfs</pre></blockquote> <p>in the command's output.</p> </blockquote> <p>The mount point must exist before <em class="emphasis">smbmount</em> is run and can be created using the <em class="emphasis">mkdir</em> command:</p> <blockquote><pre class="code"># <tt class="userinput"><b>mkdir /smb/e</b></tt></pre></blockquote> <p>The argument to the <em class="emphasis">-o</em> option might look a little complex. It is a comma-separated list of <em class="replaceable">key</em><tt class="literal">=</tt><em class="replaceable">value</em> pairs. The <tt class="literal">credentials</tt> key is set to the name of the credentials file, which is used to give <em class="emphasis">smbmount</em> a valid username and password with which to authenticate while connecting to the share. The format is identical to that used by <em class="emphasis">smbclient</em> (as explained in the previous section), so you can use the same credentials file for both clients. If you want, you can use the <em class="replaceable">key</em>=<em class="replaceable">value</em> pair <tt class="literal">username</tt>=<em class="replaceable">name</em>%<em class="replaceable">password</em> to specify the username and password directly in the <em class="emphasis">smbmount</em> command, although this is considerably less secure.</p> <a name="samba2-CHP-5-NOTE-123"/><blockquote class="note"><h4 class="objtitle">TIP</h4> <p>The <em class="emphasis">smbmount</em> command accepts the same authentication methods as <em class="emphasis">smbclient</em>. The comments in the section on <em class="emphasis">smbclient</em> regarding supplying passwords on the command line—and keeping passwords in files and environment variables—also apply here.</p> </blockquote> <p>The rest of the options tell <em class="emphasis">smbmount</em> how to translate between the SMB filesystem and the Unix filesystem, which differ in their handling of ownership and permissions. The <em class="emphasis">uid</em> and <em class="emphasis">gid</em> options specify the owner and group to be assigned to all directories and files in the mounted share.</p> <p>The <em class="emphasis">fmask</em><a name="INDEX-55"/> and <em class="emphasis">dmask</em><a name="INDEX-56"/> options specify <a name="INDEX-57"/>bitmasks for permissions of files and directories, respectively. These bitmasks are logically ANDed with whatever permissions are granted by the server to create the effective permissions on the client Unix system. On the server side, the permissions granted depend on the server's operating system. For a Windows 95/98/Me server using share-mode security, the MS-DOS read-only attribute can be set on individual files and directories and combined with the Full Access or Read Only permissions on the share as a whole. In user-level security mode, Windows 95/98/Me can have ACL-like permissions applied to the entire share, as discussed in <a href="ch04.html">Chapter 4</a>. Windows NT/2000/XP support ACLs on individual files and directories, with Full Control, Change, or Read permissions that can be applied to the entire share. If the server is a Samba server, the permissions are whatever is defined by the Samba share and the local Unix system for the individual files and directories. In every case, the permissions applied to the share act to further limit access, beyond what is specified for the individual files and directories.</p> <a name="samba2-CHP-5-NOTE-124"/><blockquote class="note"><h4 class="objtitle">TIP</h4> <p>You might think that the <em class="emphasis">fmask</em> and <em class="emphasis">dmask</em> permission masks can be used only to reduce the effective permissions on files and directories, but this is not always the case. For example, suppose that a file is being shared by a Windows 95/98/Me server using share-mode security and that some number of users have been given the Full Access password for the share. If the share is mounted with <em class="emphasis">smbmount</em> using an <em class="emphasis">fmask</em> of 666, read/write permissions are granted on the Unix system not only for the owner, but for everyone else on the Unix system as well!</p> </blockquote> <p>After mounting the <em class="filename">\\maya\d</em> share to <em class="filename">/smb/e</em>, here is what the contents of <em class="filename">/smb/e</em> look like:</p> <blockquote><pre class="code">$ <tt class="userinput"><b>cd /smb/e ; ls -l</b></tt> total 47 drwxrwxr-x 1 jay jay 512 Jan 8 20:21 CD-images drwxrwxr-x 1 jay jay 512 Jan 6 21:50 lectures -rw-rw-r-- 1 jay jay 131 Dec 18 09:12 ms-ProfPol-wp.doc -rw-rw-r-- 1 jay jay 59 Dec 18 09:12 profile-map -rw-rw-r-- 1 jay jay 131 Jan 15 05:01 readme.txt drwxrwxr-x 1 jay jay 512 Feb 4 2002 RECYCLED -rw-rw-r-- 1 jay jay 33969 Dec 10 20:22 smbclient.doc -rw-rw-r-- 1 jay jay 7759 Dec 10 20:20 smbmount.doc -rw-rw-r-- 1 jay jay 1914 Dec 10 20:17 smbsh.txt drwxrwxr-x 1 jay jay 512 Jan 10 03:54 trans</pre></blockquote> <p>For the most part, the files and directories contained in the mounted smbfs filesystem will work just like any others, except for limitations imposed by the nature of SMB networking. For example, not even the superuser can perform the operation:</p> <blockquote><pre class="code"># <tt class="userinput"><b>chown root lectures</b></tt> chown: changing ownership of 'lectures': Operation not permitted</pre></blockquote> <p>because SMB shares do not intrinsically support the idea of ownership. Some odd behaviors can result from this. For example, the command:</p> <blockquote><pre class="code"># <tt class="userinput"><b>chmod 777 readme.txt</b></tt></pre></blockquote> <p>does not produce an error message, although nothing has been changed. The file <em class="filename">readme.txt</em> still has permissions set to 664:</p> <blockquote><pre class="code"># <tt class="userinput"><b>ls -l readme.txt</b></tt> -rw-rw-r-- 1 jay jay 131 Jan 15 05:01 readme.txt</pre></blockquote> <p>Aside from little things such as these, the mounted smbfs filesystem can be used in conjunction with virtually any application, and you might be pleasantly surprised at how nicely it integrates with your Linux-based computing environment. You can even create symbolic links in the Unix filesystem, pointing to files and directories inside SMB shares. However, unless the server is a Samba server that supports Unix CIFS extensions, you will not be able to create a symbolic link inside the mounted smbfs filesystem.</p> </div> <div class="sect2"><a name="samba2-CHP-5-SECT-4.2"/> <h3 class="head2">Mounting smbfs Filesystems Automatically</h3> <p><a name="INDEX-58"/>As with other types of filesystems, an smbfs filesystem can be mounted automatically during system bootup by creating an entry for it in <em class="filename">/etc/fstab</em>. The format for the entry is as follows:</p> <blockquote><pre class="code"><em class="replaceable">Share-UNC mount-point</em> smbfs <em class="replaceable">options</em> 0 0</pre></blockquote> <p>Replace <em class="replaceable">Share-UNC</em> with the UNC of the share (using the forward slash format), and replace <em class="replaceable">mount-point</em> with the name of the directory in the Linux filesystem on which the share will be mounted. In place of <em class="replaceable">options</em>, simply use the string that you used with the <em class="emphasis">-o</em> flag in the <em class="emphasis">smbmount</em> command.</p> <p>Once you have found the arguments to use with the <em class="emphasis">smbmount</em> command to mount the share the way you like it, it is a very simple matter to create the entry for <em class="filename">/etc/fstab</em>. The <em class="emphasis">smbmount</em> command we used to mount the share <em class="filename">\\maya\e</em> on <em class="filename">/smb/e</em> would translate to this <em class="filename">/etc/fstab</em> entry:</p> <blockquote><pre class="code">//maya/e /smb/e smbfs credentials=/home/jay/.smbpw,uid=jay,gid=jay,fmask=664,dmask=775 0 0 <i class="lineannotation">(Please note that this should all go on one line.)</i></pre></blockquote> <a name="samba2-CHP-5-NOTE-125"/><blockquote class="note"><h4 class="objtitle">WARNING</h4> <p>If you make a mistake in modifying <em class="filename">/etc/fstab</em><a name="INDEX-59"/><a name="INDEX-60"/>, your system might not reboot properly, and you might be forced to boot into single-user mode to fix the problem. Before you edit <em class="filename">/etc/fstab</em>, be sure to make a backup copy of it, and be prepared to recover your system if anything goes wrong.</p> </blockquote> <p>Once the entry has been added, the system will automatically mount the share when booting. Or, the system administrator can manually mount or unmount the share with commands such as these:</p> <blockquote><pre class="code"># <tt class="userinput"><b>mount /smb/e</b></tt> # <tt class="userinput"><b>umount /smb/e</b></tt></pre></blockquote> <a name="samba2-CHP-5-NOTE-126"/><blockquote class="note"><h4 class="objtitle">TIP</h4> <p>It is possible to use <em class="emphasis">mount</em> and <em class="emphasis">umount</em> by giving them the UNC for the share using forward slashes, as in our <em class="filename">/etc/fstab</em> entry. However, be careful about this. A share might be listed more than once in <em class="filename">/etc/fstab</em> so that it can be mounted at more than one place in the Linux filesystem. If you use the UNC to specify the share you wish to mount or unmount, you might cause it to be mounted or unmounted at another mount point from the one you intended.</p> </blockquote> </div> <div class="sect2"><a name="samba2-CHP-5-SECT-4.3"/> <h3 class="head2">Common smbmount Options</h3> <p><a href="ch05.html#samba2-CHP-5-TABLE-1">Table 5-1</a> lists <em class="replaceable">key</em><tt class="literal">=</tt><em class="replaceable">value</em> pairs that can be used with the <em class="emphasis">-o</em> option of <em class="emphasis">smbmount</em> or in the options field of the <em class="filename">/etc/fstab</em> entry for the smbfs filesystem. See the <em class="emphasis">smbmount</em> manual page for a complete list of options.</p> <a name="samba2-CHP-5-TABLE-1"/><h4 class="head4">Table 5-1. smbmount options</h4><table border="1"> <tr> <th> <p>Key</p> </th> <th> <p>Value</p> </th> <th> <p>Function</p> </th> </tr> <tr> <td> <p><tt class="literal">username</tt></p> </td> <td> <p>string</p> </td> <td> <p>Provides the username, and optionally the password and workgroup, for authentication.</p> </td> </tr> <tr> <td> <p><tt class="literal">password</tt></p> </td> <td> <p>string</p> </td> <td> <p>Provides the share or domain password, if it hasn't been supplied by another means.</p> </td> </tr> <tr> <td> <p><tt class="literal">credentials</tt></p> </td> <td> <p>string</p> </td> <td> <p>Name of file containing the username and password.</p> </td> </tr> <tr> <td> <p><tt class="literal">uid</tt></p> </td> <td> <p>string or numeric</p> </td> <td> <p>User ID to apply to all files and directories of the mounted share.</p> </td> </tr> <tr> <td> <p><tt class="literal">gid</tt></p> </td> <td> <p>string or numeric</p> </td> <td> <p>Group ID to apply to all files and directories of the mounted share.</p> </td> </tr> <tr> <td> <p><tt class="literal">fmask</tt></p> </td> <td> <p>numeric</p> </td> <td> <p>Permissions to apply to files. Default is based on current umask.</p> </td> </tr> <tr> <td> <p><tt class="literal">dmask</tt></p> </td> <td> <p>numeric</p> </td> <td> <p>Permissions to apply to directories. Default is based on current umask.</p> </td> </tr> <tr> <td> <p><tt class="literal">debug</tt></p> </td> <td> <p>numeric</p> </td> <td> <p>Debug level.</p> </td> </tr> <tr> <td> <p><tt class="literal">workgroup</tt></p> </td> <td> <p>string</p> </td> <td> <p>Name of workgroup of remote server.</p> </td> </tr> <tr> <td> <p><tt class="literal">guest</tt></p> </td> <td> <p>(none)</p> </td> <td> <p>Suppresses password prompt.</p> </td> </tr> <tr> <td> <p><tt class="literal">ro</tt></p> </td> <td> <p>(none)</p> </td> <td> <p>Mount read-only.</p> </td> </tr> <tr> <td> <p><tt class="literal">rw</tt></p> </td> <td> <p>(none)</p> </td> <td> <p>Mount read/write. This is the default.</p> </td> </tr> <tr> <td> <p><tt class="literal">ttl</tt></p> </td> <td> <p>numeric</p> </td> <td> <p>Amount of time to cache the contents of directories. Defaults to 1000 ms <a name="INDEX-62"/>.</p> </td> </tr> </table> </div> </div> <div class="sect1"><a name="samba2-CHP-5-SECT-5"/> <h2 class="head1">smbsh</h2> <p>The <em class="emphasis">smbsh</em><a name="INDEX-63"/> program is part of the Samba suite and works on some, but not all, Unix variants.<a name="FNPTR-3"/><a href="#FOOTNOTE-3">[3]</a> Effectively, it adds a wrapper around the user's command shell, enabling it and common Unix utilities to work on files and directories in SMB shares, in addition to files and directories in the local Unix filesystem. From the user's perspective, the effect is that of a simulated mount of the SMB shares onto the Unix filesystem.</p> <p><em class="emphasis">smbsh</em> works by running the shell and programs run from it in an environment in which calls to the standard C library are redirected to the <em class="emphasis">smbwrapper</em><a name="INDEX-64"/> library, which has support for operating on SMB shares. This redirection can work only if the program being run is dynamically linked. Fortunately, modern Unix versions ship with most common utilities linked dynamically rather than statically.</p> <a name="samba2-CHP-5-NOTE-127"/><blockquote class="note"><h4 class="objtitle">TIP</h4> <p>To determine whether a program is dynamically or statically linked, try using the <em class="emphasis">file</em> command.</p> </blockquote> <p>To use <em class="emphasis">smbsh</em>, your Samba installation must be configured using the configure option <tt class="literal">--with-smbwrapper</tt>.</p> <p>If you have a number of Unix systems with the same host operating system and architecture and don't want to bother with a full Samba installation, you can simply move the following files to the other systems:</p> <blockquote><pre class="code">/usr/local/samba/bin/smbsh /usr/local/samba/bin/smbwrapper.so /usr/local/samba/lib/smb.conf</pre></blockquote> <p>Make sure that <em class="filename">/usr/local/samba/bin</em> is in your shell's search path. The <em class="filename">smb.conf</em><a name="INDEX-65"/><a name="INDEX-66"/> file is needed only for <em class="emphasis">smbsh</em> to determine the workgroup or domain and does not need to be as elaborate as your Samba server's configuration file.</p> <div class="sect2"><a name="samba2-CHP-5-SECT-5.1"/> <h3 class="head2">An Interactive Session with smbsh</h3> <p><a name="INDEX-67"/>To start <em class="emphasis">smbsh</em>, simply type in the <em class="emphasis">smbsh</em> command at the shell prompt. You will be prompted for a username and password with which to authenticate on the SMB network:</p> <blockquote><pre class="code">$ <tt class="userinput"><b>smbsh</b></tt> Username: davecb Password: smbsh$</pre></blockquote> <p>While working within the <em class="emphasis">smbsh</em> shell, you have a virtual <em class="filename">/smb</em> directory. This does not actually exist in the Unix filesystem and is supported within <em class="emphasis">smbsh</em> only to help organize the SMB shares in a structure familiar to Unix users. You can list the contents of the <em class="filename">/smb</em> virtual directory and get a list of workgroups in the local network, which are also presented as virtual directories:</p> <blockquote><pre class="code">smbsh$ <tt class="userinput"><b>cd /smb ; ls</b></tt> ZOOL PLANK BACIL</pre></blockquote> <p>You can change your working directory to one of the workgroup virtual directories, and listing one of them will show the computers in the workgroup:</p> <blockquote><pre class="code">smbsh$ <tt class="userinput"><b>cd ZOOL ; ls</b></tt> ANTILLES DODO MILO SEAL ARGON HANGGLIDE OSTRICH SPARTA BALLET INFUSION PLAQUE THEBES CHABLIS JAZ PRAETORIAN TJ COBRA KIKO RAYOPCI TRANCE COUGUR MACHINE-HEADPCI RUMYA VIPERPCI CRUSTY MATHUMA SCOT</pre></blockquote> <p>Likewise, you can change your current directory to, and list the contents of, a computer virtual directory, and then you can see a listing of shares offered by that computer:</p> <blockquote><pre class="code">smbsh$ <tt class="userinput"><b>cd scot ; ls</b></tt> ADMIN$ davecb nc np2s pl ace dhcp-mrk03 np nps xp cl ep np2 opcom</pre></blockquote> <p>This is the lowest level of <em class="emphasis">smbsh</em>'s virtual directory system. Once you <em class="emphasis">cd</em> into a share, you are within the SMB share on the remote computer:</p> <blockquote><pre class="code">smbsh$ <tt class="userinput"><b>cd davecb ; ls</b></tt> Mail mkanalysis_dirs.idx SUNWexplo nfs.ps Sent nsmail allsun.html projects.txt bin sumtimex</pre></blockquote> <p>Once in a remote share, most of the Unix shell utilities will work, and you can operate on files and directories much as you would on any Unix system. You can even create symbolic links in the Unix filesystem pointing to files and directories in the SMB share. However, attempts to create symbolic links in the SMB share will fail unless the share is being served by Samba with support for Unix CIFS extensions.</p> </div> </div> <div class="sect1"><a name="samba2-CHP-5-SECT-6"/> <h2 class="head1">smbutil and mount_smbfs</h2> <p>The <em class="emphasis">smbutil</em> and <em class="emphasis">mount_smbfs</em> programs provide SMB client functionality for FreeBSD, Darwin, and Mac OS X. Neither of the programs is part of the Samba distribution; however, we are including them to give you a little additional support in case you have BSD-related Unix systems on your network.</p> <div class="sect2"><a name="samba2-CHP-5-SECT-6.1"/> <h3 class="head2">smbutil</h3> <p>The <em class="emphasis">smbutil</em><a name="INDEX-68"/> program provides functionality similar to some of the Samba suite's command-line utilities. It can be used to list the shares available on an SMB server or perform NetBIOS name lookups.</p> <p>The first argument given to <em class="emphasis">smbutil</em> is one of a number of subcommands and is usually followed by arguments specific to the subcommand. For example, to list the resources offered by a server, use the <em class="emphasis">view</em> subcommand, and enter your server password when prompted:</p> <blockquote><pre class="code">% <tt class="userinput"><b>smbutil view //vamana</b></tt> Password: Share Type Comment ------------------------------------------------------------- public disk SS2500 printer Stylus Scan 2500 IPC$ pipe IPC Service (Samba 2.2.5) ADMIN$ disk IPC Service (Samba 2.2.5) leonvs disk User Home Directories 5 shares listed from 5 available</pre></blockquote> <p>If you wish to connect to the server with a username that differs from that on your client, you can specify it on the command line by preceding the name of the server with the username and using an at sign (<tt class="literal">@</tt>) as a separator:</p> <blockquote><pre class="code">% <tt class="userinput"><b>smbutil view //leonvs@vamana</b></tt></pre></blockquote> <p>You can also include the password after the username, using a colon (:) as a separator, to avoid being prompted for it:</p> <blockquote><pre class="code">% <tt class="userinput"><b>smbutil view //leonvs:leonspassword@vamana</b></tt></pre></blockquote> <p>Typing your password in the open like this is strongly discouraged. It's a little better if you use an encrypted password, which you can generate using <em class="emphasis">smbutil</em>'s <em class="emphasis">crypt</em> subcommand:</p> <blockquote><pre class="code">% <tt class="userinput"><b>smbutil crypt leonspassword</b></tt> $$1625a5723293f0710e5faffcfc6</pre></blockquote> <p>This can then be used in place of a clear-text password. However, the encryption is not particularly strong and will foil only the most casual inspection. As noted earlier, the only reasonably secure method of providing a password is to be prompted for it.</p> <p>While starting up, <em class="emphasis">smbutil</em> reads the file <em class="filename">.nsmbrc</em><a name="INDEX-69"/> in the user's home directory. Also, the file <em class="filename">/usr/local/etc/nsmb.conf</em><a name="INDEX-70"/><a name="INDEX-71"/> is read, and directives in that file override those in users' <em class="filename">~/.nsmbrc</em> files. This is to allow administrators to apply mandatory settings to all users. Directives can be placed in this file using the section and parameter format similar to that of the Samba configuration file. A list of common configuration parameters is given in <a href="ch05.html#samba2-CHP-5-TABLE-2">Table 5-2</a>.</p> <p>For example, to keep your password in your <em class="filename">~/.nsmbrc</em> file, you can create an entry in the file such as the following:</p> <blockquote><pre class="code">[VAMANA:LEONVS] password=$$1625a5723293f0710e5faffcfc6</pre></blockquote> <p>The section heading in brackets specifies the SMB server's NetBIOS name and the username to which the subsequent parameter settings apply. (The hostname and username should be supplied in uppercase characters.) Section headings can also consist of just a hostname or can contain a share name as a third element for specifying parameters applicable to a single share. Finally, if a <tt class="literal">[default]</tt> section is present, the settings in it apply to all connections.</p> <p>The following example <em class="filename">.nsmbrc</em> shows some of the other parameters you might use:</p> <blockquote><pre class="code">[default] username=leonvs # NetBIOS name server nbns=192.168.1.3 [VAMANA] # server IP address addr=192.168.1.6 workgroup=TEST [VAMANA:LEONVS] password=$$1625a5723293f0710e5faffcfc6</pre></blockquote> <p>Another thing you can do with <em class="emphasis">smbutil</em> is <a name="INDEX-72"/><a name="INDEX-73"/><a name="INDEX-74"/>translate between IP addresses or DNS names and <a name="INDEX-75"/>NetBIOS names. For example, the <em class="emphasis">status</em> subcommand takes an IP address or DNS hostname as an argument and returns the corresponding SMB server's NetBIOS name and workgroup:</p> <blockquote><pre class="code">% <tt class="userinput"><b>smbutil status 192.168.1.6</b></tt> Workgroup: TEST Server: VAMANA</pre></blockquote> <p>The <em class="emphasis">lookup</em> subcommand returns the IP address associated with a given NetBIOS hostname. A NetBIOS name server can be optionally specified with the <em class="emphasis">-w</em> argument:</p> <blockquote><pre class="code">% <tt class="userinput"><b>smbutil lookup -w 192.168.1.3 VAMANA</b></tt> Got response from 192.168.1.3 IP address of VAMANA: 192.168.1.6</pre></blockquote> </div> <div class="sect2"><a name="samba2-CHP-5-SECT-6.2"/> <h3 class="head2">mount_smbfs</h3> <p>The <em class="emphasis">mount_smbfs</em><a name="INDEX-76"/> program performs essentially the same function as <em class="emphasis">smbmount</em> on Linux. It mounts an SMB share on a directory in the local filesystem. The SMB share can then be accessed just like any other directory, subject to some behavioral differences noted earlier in <a href="ch05.html#samba2-CHP-5-SECT-4.1">Section 5.4.1</a>.</p> <p>The command synopsis for <em class="emphasis">mount_smbfs</em> is:</p> <blockquote><pre class="code">mount_smbfs <em class="replaceable">[options]</em> <em class="replaceable">Share-UNC</em> <em class="replaceable">mount-point</em></pre></blockquote> <p>where <em class="replaceable">Share-UNC</em> is of the form:</p> <blockquote><pre class="code">//[<em class="replaceable">workgroup</em>;][<em class="replaceable">username</em>[:<em class="replaceable">password</em>]@]<em class="replaceable">server</em>[/<em class="replaceable">share</em>]</pre></blockquote> <p>For example:</p> <blockquote><pre class="code"># <tt class="userinput"><b>mount_smbfs '//TEST;leonvs:$$1625a5723293f0710e5faffcfc6@vamana/leonvs' /</b></tt> \<tt class="userinput"><b>Volumes/leonvs</b></tt></pre></blockquote> <p>The ownership and permissions of the mount point determine the default ownership and permissions for files and directories in the mounted share. These can be modified with command-line arguments, like this:</p> <blockquote><pre class="code"># <tt class="userinput"><b>mount_smbfs -u leonvs -g admin -f 0750 -d 0755 //leonvs@vamana/leonvs </b></tt> \<tt class="userinput"><b>/Volumes/leonvs</b></tt></pre></blockquote> <p>In this example, the files and directories in the mounted share will be owned by the user leonvs and the group admin, with files and directories having permissions 750 and 755, respectively. (As usual, the permissions are specified in the octal format used by the Unix <em class="emphasis">chmod</em> command.)</p> <p>The <em class="emphasis">mount_smbfs</em><a name="INDEX-77"/><a name="INDEX-78"/> command also makes use of settings in <em class="filename">/usr/local/etc/nsmb.conf</em> and <em class="filename">~/.nsmbrc</em>, as described earlier. A list of common configuration parameters and command-line options is provided in <a href="ch05.html#samba2-CHP-5-TABLE-2">Table 5-2</a>.</p> <a name="samba2-CHP-5-TABLE-2"/><h4 class="head4">Table 5-2. Common smbutil and mount_smbfs options</h4><table border="1"> <tr> <th> <p>Command-line option</p> </th> <th> <p>Configuration file parameter</p> </th> <th> <p>Description</p> </th> </tr> <tr> <td> <p><tt class="literal">-I</tt> <em class="replaceable">hostname</em></p> </td> <td> <p><tt class="literal">addr</tt></p> </td> <td> <p>Avoid NetBIOS name resolution and connect to the server using the specified DNS hostname or IP address.</p> </td> </tr> <tr> <td> <p>-N</p> </td> <td> <p><em class="emphasis">none</em></p> </td> <td> <p>Do not prompt for a password.</p> </td> </tr> <tr> <td> <p>-R <em class="replaceable">count</em></p> </td> <td> <p><tt class="literal">retry_count</tt></p> </td> <td> <p>Number of times to retry connection before giving up.</p> </td> </tr> <tr> <td> <p>-T <em class="replaceable">seconds</em></p> </td> <td> <p><tt class="literal">timeout</tt></p> </td> <td> <p>Timeout, in seconds, per connection request.</p> </td> </tr> <tr> <td> <p>-U <em class="replaceable">username</em></p> </td> <td> <p><tt class="literal">username</tt></p> </td> <td> <p>Username to use for authentication. Defaults to Unix username.</p> </td> </tr> <tr> <td> <p>-W <em class="replaceable">workgroup</em></p> </td> <td> <p><tt class="literal">workgroup</tt></p> </td> <td> <p>Name of workgroup of remote server.</p> </td> </tr> <tr> <td> <p>-d <em class="replaceable">mode</em></p> </td> <td> <p><em class="emphasis">none</em></p> </td> <td> <p>Permissions to apply to directories in the mounted share. Defaults to the same as the file permissions, plus an execute (search) bit whenever the read bit is set.</p> </td> </tr> <tr> <td> <p>-f <em class="replaceable">mode</em></p> </td> <td> <p><em class="filename">none</em></p> </td> <td> <p>Permissions to apply to files in the mounted share. Defaults to the same as the permissions set on the directory used as the mount point.</p> </td> </tr> <tr> <td> <p>-g <em class="replaceable">group</em></p> </td> <td> <p><em class="emphasis">none</em></p> </td> <td> <p>Name or numeric GID to apply to all files and directories in the mounted share. Defaults to the group of the directory used as the mount point.</p> </td> </tr> <tr> <td> <p>-n <em class="replaceable">long</em></p> </td> <td> <p><em class="emphasis">none</em></p> </td> <td> <p>Disable support for long filenames. Restrict filenames to 8.3 naming standard.</p> </td> </tr> <tr> <td> <p>-u <em class="replaceable">username</em></p> </td> <td> <p><em class="emphasis">none</em></p> </td> <td> <p>Username or numeric UID to apply as the owner of all files and directories in the mounted share. Defaults to the owner of the directory used as the mount point.</p> </td> </tr> <tr> <td> <p>-w <em class="replaceable">hostname</em></p> </td> <td> <p><tt class="literal">nbns</tt></p> </td> <td> <p>Hostname or IP address of the NetBIOS name server.</p> </td> </tr> <tr> <td> <p><em class="emphasis">none</em></p> </td> <td> <p><tt class="literal">password</tt></p> </td> <td> <p>Password to use for authentication.</p> </td> </tr> </table> </div> <div class="sect2"><a name="samba2-CHP-5-SECT-6.3"/> <h3 class="head2">Mac OS X</h3> <p><a name="INDEX-79"/>In addition to <em class="emphasis">smbutil</em> and <em class="emphasis">mount_smbfs</em>, OS X includes a graphical interface to the functionality they provide. To use this interface, open the Go menu and select the Connect to Server . . . menu item. Instead of using a UNC, specify the share in the form of a Uniform Resource Identifier (URI) with a prefix of <tt class="literal">smb://</tt> entered in the Address field, as shown in <a href="ch05.html#samba2-CHP-5-FIG-5">Figure 5-5</a>.</p> <div class="figure"><a name="samba2-CHP-5-FIG-5"/><img src="figs/sam2_0505.gif"/></div><h4 class="head4">Figure 5-5. OS X Connect to Server dialog</h4> <p>You can specify a server, share, workgroup, username, and password (optionally encrypted with <em class="emphasis">smbutil crypt</em>) in the URI, in the same format as the UNC argument to <em class="emphasis">mount_smbfs</em>. If you don't specify a share name in the URI, you will be shown a window that lets you choose from a list of shares available to mount. See <a href="ch05.html#samba2-CHP-5-FIG-6">Figure 5-6</a>.</p> <div class="figure"><a name="samba2-CHP-5-FIG-6"/><img src="figs/sam2_0506.gif"/></div><h4 class="head4">Figure 5-6. Selecting a share to mount</h4> <p>Only guest-accessible shares will show up in the list until you've authenticated. After pressing the Authenticate button, you'll be prompted for a workgroup, username, and password, as shown in <a href="ch05.html#samba2-CHP-5-FIG-7">Figure 5-7</a>. You'll also see this dialog if you provide a share name in the URI, but not a username and password.<a name="FNPTR-4"/><a href="#FOOTNOTE-4">[4]</a></p> <div class="figure"><a name="samba2-CHP-5-FIG-7"/><img src="figs/sam2_0507.gif"/></div><h4 class="head4">Figure 5-7. Client authentication</h4> <p>As usual for Mac OS X, shares are mounted under <em class="filename">/Volumes</em>, but show up in the root of the Finder hierarchy.</p> <p>If you have a WINS server on your network, you can provide the server's IP address in the Directory Access application, or by using the <tt class="literal">wins</tt> <tt class="literal">server</tt> parameter in <em class="filename">/etc/smb.conf</em>.</p> <p>If you don't know the name of a server to which you wish to connect, you can look for it in the browse list, using the graphical frontend to the <em class="emphasis">nmblookup</em> command provided with Samba. Click the downward-pointing arrow in the Connect to Server . . . dialog box to show a hierarchical, column-based view of available workgroups and servers, similar to that shown in <a href="ch05.html#samba2-CHP-5-FIG-8">Figure 5-8</a>. If your client is also acting as an SMB file server, it won't show up in its own browse list.<a name="INDEX-80"/></p> <div class="figure"><a name="samba2-CHP-5-FIG-8"/><a name="INDEX-81"/><img src="figs/sam2_0508.gif"/></div><h4 class="head4">Figure 5-8. Browsing the network</h4> </div> </div> <hr/><h4 class="head4">Footnotes</h4><blockquote><a name="FOOTNOTE-1"/> <p><a href="#FNPTR-1">[1]</a> An alternative to extracting the tar archive directly to the SMB share is to use the Unix system's <em class="emphasis">tar</em> command to extract it to a directory on the Unix server, then copy the desired file(s) to a shared directory. This allows a greater amount of control over the restoration process, as when correcting for an accidental file deletion or reverting a set of files to a previous condition.</p> <a name="FOOTNOTE-2"/> <p><a href="#FNPTR-2">[2]</a> Samba Versions 2.2.4 and later have support for Unix CIFS extensions developed by Hewlett-Packard, which add full support for Unix ownership, group, and permissions in smbfs filesystems when shared between two Samba systems. You will also need a recent version of smbfs in your Linux kernel.</p> <a name="FOOTNOTE-3"/> <p><a href="#FNPTR-3">[3]</a> At the time of this writing, <em class="emphasis">smbsh</em> does not work on HP/UX or Linux. However, Linux support might return in the future.</p> <a name="FOOTNOTE-4"/> <p><a href="#FNPTR-4">[4]</a> If you've previously stored your authentication information in a Keychain, you will instead be prompted for your Keychain password.</p> </blockquote><hr/><h4 class="head4"><a href="toc.html">TOC</a></h4></body></html>