Compiling and installing Samba on a Unix host

Samba FAQ
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# Chapter 2. Compiling and installing Samba on a Unix host

# 2.1. I can't see the Samba server in any browse lists!

See Browsing.html in the docs directory of the samba source for more information on browsing.

If your GUI client does not permit you to select non-browsable servers, you may need to do so on the command line. For example, under Lan Manager you might connect to the above service as disk drive M: thusly:

       net use M: \\mary\fred

The details of how to do this and the specific syntax varies from client to client - check your client's documentation.

# 2.2. Some files that I KNOW are on the server doesn't show up when I view the files from my client!

See the next question.

# 2.3. Some files on the server show up with really wierd filenames when I view the files from my client!

If you check what files are not showing up, you will note that they are files which contain upper case letters or which are otherwise not DOS-compatible (ie, they are not legal DOS filenames for some reason).

The Samba server can be configured either to ignore such files completely, or to present them to the client in "mangled" form. If you are not seeing the files at all, the Samba server has most likely been configured to ignore them. Consult the man page smb.conf(5) for details of how to change this - the parameter you need to set is "mangled names = yes".

# 2.4. My client reports "cannot locate specified computer" or similar

This indicates one of three things: You supplied an incorrect server name, the underlying TCP/IP layer is not working correctly, or the name you specified cannot be resolved.

After carefully checking that the name you typed is the name you should have typed, try doing things like pinging a host or telnetting to somewhere on your network to see if TCP/IP is functioning OK. If it is, the problem is most likely name resolution.

If your client has a facility to do so, hardcode a mapping between the hosts IP and the name you want to use. For example, with Lan Manager or Windows for Workgroups you would put a suitable entry in the file LMHOSTS. If this works, the problem is in the communication between your client and the netbios name server. If it does not work, then there is something fundamental wrong with your naming and the solution is beyond the scope of this document.

If you do not have any server on your subnet supplying netbios name resolution, hardcoded mappings are your only option. If you DO have a netbios name server running (such as the Samba suite's nmbd program), the problem probably lies in the way it is set up. Refer to Section Two of this FAQ for more ideas.

By the way, remember to REMOVE the hardcoded mapping before further tests :-)

# 2.5. My client reports "cannot locate specified share name" or similar

This message indicates that your client CAN locate the specified server, which is a good start, but that it cannot find a service of the name you gave.

The first step is to check the exact name of the service you are trying to connect to (consult your system administrator). Assuming it exists and you specified it correctly (read your client's docs on how to specify a service name correctly), read on:

Many clients cannot accept or use service names longer than eight characters.
Many clients cannot accept or use service names containing spaces.
Some servers (not Samba though) are case sensitive with service names.
Some clients force service names into upper case.

# 2.6. Printing doesn't work

Make sure that the specified print command for the service you are connecting to is correct and that it has a fully-qualified path (eg., use "/usr/bin/lpr" rather than just "lpr").

Make sure that the spool directory specified for the service is writable by the user connected to the service. In particular the user "nobody" often has problems with printing, even if it worked with an earlier version of Samba. Try creating another guest user other than "nobody".

Make sure that the user specified in the service is permitted to use the printer.

Check the debug log produced by smbd. Search for the printer name and see if the log turns up any clues. Note that error messages to do with a service ipc$ are meaningless - they relate to the way the client attempts to retrieve status information when using the LANMAN1 protocol.

If using WfWg then you need to set the default protocol to TCP/IP, not Netbeui. This is a WfWg bug.

If using the Lanman1 protocol (the default) then try switching to coreplus. Also not that print status error messages don't mean printing won't work. The print status is received by a different mechanism.

# 2.7. My client reports "This server is not configured to list shared resources"

Your guest account is probably invalid for some reason. Samba uses the guest account for browsing in smbd. Check that your guest account is valid.

See also 'guest account' in smb.conf man page.

# 2.8. Log message "you appear to have a trapdoor uid system"

This can have several causes. It might be because you are using a uid or gid of 65535 or -1. This is a VERY bad idea, and is a big security hole. Check carefully in your /etc/passwd file and make sure that no user has uid 65535 or -1. Especially check the "nobody" user, as many broken systems are shipped with nobody setup with a uid of 65535.

It might also mean that your OS has a trapdoor uid/gid system :-)

This means that once a process changes effective uid from root to another user it can't go back to root. Unfortunately Samba relies on being able to change effective uid from root to non-root and back again to implement its security policy. If your OS has a trapdoor uid system this won't work, and several things in Samba may break. Less things will break if you use user or server level security instead of the default share level security, but you may still strike problems.

The problems don't give rise to any security holes, so don't panic, but it does mean some of Samba's capabilities will be unavailable. In particular you will not be able to connect to the Samba server as two different uids at once. This may happen if you try to print as a "guest" while accessing a share as a normal user. It may also affect your ability to list the available shares as this is normally done as the guest user.

Complain to your OS vendor and ask them to fix their system.

Note: the reason why 65535 is a VERY bad choice of uid and gid is that it casts to -1 as a uid, and the setreuid() system call ignores (with no error) uid changes to -1. This means any daemon attempting to run as uid 65535 will actually run as root. This is not good!

# 2.9. Why are my file's timestamps off by an hour, or by a few hours?

This is from Paul Eggert eggert@twinsun.com.

Most likely it's a problem with your time zone settings.

Internally, Samba maintains time in traditional Unix format, namely, the number of seconds since 1970-01-01 00:00:00 Universal Time (or ``GMT''), not counting leap seconds.

On the server side, Samba uses the Unix TZ variable to convert internal timestamps to and from local time. So on the server side, there are two things to get right.

The Unix system clock must have the correct Universal time. Use the shell command "sh -c 'TZ=UTC0 date'" to check this.
The TZ environment variable must be set on the server before Samba is invoked. The details of this depend on the server OS, but typically you must edit a file whose name is /etc/TIMEZONE or /etc/default/init, or run the command `zic -l'.

TZ must have the correct value.

If possible, use geographical time zone settings (e.g. TZ='America/Los_Angeles' or perhaps TZ=':US/Pacific'). These are supported by most popular Unix OSes, are easier to get right, and are more accurate for historical timestamps. If your operating system has out-of-date tables, you should be able to update them from the public domain time zone tables at ftp://elsie.nci.nih.gov/pub/.

If your system does not support geographical timezone settings, you must use a Posix-style TZ strings, e.g. TZ='PST8PDT,M4.1.0/2,M10.5.0/2' for US Pacific time. Posix TZ strings can take the following form (with optional items in brackets):

    	StdOffset[Dst[Offset],Date/Time,Date/Time]

where:

`Std' is the standard time designation (e.g. `PST').
`Offset' is the number of hours behind UTC (e.g. `8'). Prepend a `-' if you are ahead of UTC, and append `:30' if you are at a half-hour offset. Omit all the remaining items if you do not use daylight-saving time.
`Dst' is the daylight-saving time designation (e.g. `PDT').
The optional second `Offset' is the number of hours that daylight-saving time is behind UTC. The default is 1 hour ahead of standard time.
`Date/Time,Date/Time' specify when daylight-saving time starts and ends. The format for a date is `Mm.n.d', which specifies the dth day (0 is Sunday) of the nth week of the mth month, where week 5 means the last such day in the month. The format for a time is [h]h[:mm[:ss]], using a 24-hour clock.

Other Posix string formats are allowed but you don't want to know about them.

On the client side, you must make sure that your client's clock and time zone is also set appropriately. [[I don't know how to do this.]] Samba traditionally has had many problems dealing with time zones, due to the bizarre ways that Microsoft network protocols handle time zones.

# 2.10. How do I set the printer driver name correctly?

Question: " On NT, I opened "Printer Manager" and "Connect to Printer". Enter ["\\ptdi270\ps1"] in the box of printer. I got the following error message "

         You do not have sufficient access to your machine
         to connect to the selected printer, since a driver
         needs to be installed locally.

Answer:

In the more recent versions of Samba you can now set the "printer driver" in smb.conf. This tells the client what driver to use. For example:

         printer driver = HP LaserJet 4L

With this, NT knows to use the right driver. You have to get this string exactly right.

To find the exact string to use, you need to get to the dialog box in your client where you select which printer driver to install. The correct strings for all the different printers are shown in a listbox in that dialog box.

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