Setting Up Samba In Ubuntu

By | January 31, 2010

What is Samba and when do you need it?
Samba is a set of tools to share files and printers. It implements the SMB network protocol, which is the heart of Windows networking. OS X also recognises Samba shares.

Samba can be used to:

* Act as a server for Windows (or Samba) clients: share folders and printers, including PDF pseudo-printers so all the computers in your network may write PDF files
* Act as a domain controller in a Windows network (authenticating users, etc.)
* Do some more complex things, such as using a Windows domain controller to authenticate the users of a Linux/UNIX machine

Samba is freely available under the GNU General Public License. More information about Samba can be found at http://www.samba.org.

What to install
The samba package is a meta-package intended to be installed on servers. Clients do not need this meta-package (you are acting as a client if you need to access files on another computer). For example, installing samba is not necessary if you only need your Ubuntu system to do any of the following:

* Access shared folders, drives and printers on a Windows computer (that is, act as a client with Windows servers). To do this, you only need the smbfs plugin. See MountWindowsSharesPermanently for more information.
* Have your Windows computer use (via a network) a printer that is attached to a Linux computer. CUPS can be configured to make the printer accessible to the network.
* Share directories between two Linux computers. You can use NFS or setup an SSH server on one computer and access it from other computers using an scp or sftp client, or Places -> Connect to Server… and choose “SSH” as the service type.

Nautilus Integration

If you want to be able to share folders with nautilus (the file browser), install the nautilus-share package (installed by default in Ubuntu 9.10 Desktop edition):

sudo apt-get install nautilus-share

Server

If you wish your computer to act as a Samba server (act as a file or printer server) then install the samba package (see InstallingSoftware for details):

sudo aptitude install samba

Client

The samba package is not needed on clients. Install smbfs instead (see InstallingSoftware for details):

sudo aptitude install smbfs

If you want to connect to a Samba server (Windows server or an Ubuntu server running Samba) you have two options, you can use the smbclient command or you can directly mount the samba file system via smbfs.

Command line

Ubuntu will connect to a Samba server out of the box via smbclient. This is a similar to a FTP connection. Once connected, you can use commands such as ls, cd , put, and get.

smbfs

This package allows clients to mount Samba file shares, allowing them to act as local disks. Most people will prefer this method.

Samba Client – Manual Configuration

This section covers how to manually configure and connect to a SMB file server from an Ubuntu client. smbclient is a command line tool similar to a ftp connection while smbfs allows you to mount a SMB file share. Once a SMB share is mounted it acts similar to a local hard drive (you can access the SMB share with your file browser (nautilus, konqueror, thunar, other).

Connecting to a Samba File Server from the command line

Connecting from the command line is similar to a ftp connection.

List public SMB shares with

smbclient -L //server -U user

Connect to a SMB share with

smbclient //server/share -U user

Enter you user password.

You can connect directly with

smbclient //server/share -U user%password

but your password will show on the screen (less secure).

Once connected you will get a prompt that looks like this :

smb: >

Type “help” , without quotes, at the prompt for a list of available commands.

Connecting using CIFS

CIFS is included in the smbfs package and is a replacement for smbfs (I know, the terminology here is a little confusing).

Reference : http://linux-cifs.samba.org/

As above, install by any method, smbfs.

Allow non-root users to mount SMB shares

By default only root may mount SMB shares on the command line. To allow non-root users to mount SMB shares you could set the SUID, but I advise you configure sudo. You should configure sudo with visudo

You may either allow the gruop “users” to mount SMB shares, or add a group, samba, and add users you wish to allow to mount SMB shares to the samba group.

sudo groupadd samba
sudo adduser user samba

Change “user” to the username you wish to add to the samba group.

sudo visudo

In the “group” section add your group you wish to allow to mount SMB shares

Add a line in the “group” section :

## Members of the admin group may gain root privileges
%admin ALL=(ALL) ALL
%samba ALL=(ALL) /bin/mount,/bin/umount,/sbin/mount.cifs,/sbin/umount.cifs

Change “%samba” to “%users” if you wish to allow members of the users group to mount SMB shares.

The following will mount the myshare folder on myserver to ~/mnt (it will be in your home directory):

mkdir ~/mnt
sudo mount -t cifs //myserver_ip_address/myshare ~/mnt -o username=samb_user,noexec

Note: “samba_user” = the user name on the samba server (may be different from your log-in name on the client).

The “noexec” option prevents executable scripts running from the SMB share.

You will be asked for BOTH your sudo and then your samba_user password.

To umount,

sudo umount ~/mnt

Automagically mount SMB shares

In order to have a share mounted automatically every time you reboot, you need to do the following:

With any editor, create a file containing your Windows/Samba user account details:

gksu gedit /etc/samba/user

KDE users must use kdesu rather than gksu and instead of Gedit they can use Kwrite as editor.

… it should contain two lines as follows:

username=samba_user
password=samba_user_password

Note: “samba_user” = the user name on the samba server (may be different from your log-in name on the client). “samba_user_password” is the password you assigned to the samba_user on the samba server.

Save the file and exit gedit.

Change the permissions on the file for security:

sudo chmod 0400 /etc/samba/user # permissions of 0400 = read only

Now create a directory where you want to mount your share (e.g. /media/samba_share):

sudo mkdir /media/samba_share

Now, using any editor, and add a line to /etc/fstab for your SMB share as follows:

sudo cp /etc/fstab /etc/fstab.bak
gksu gedit /etc/fstab

Add a line for your SMB share:

//myserver_ip_address/m
yshare /media/samba_share cifs credentials=/etc/samba/user,noexec 0 0

The share will mount automatically when you boot. The “noexec” option prevents executable scripts running from the SMB share.

To mount the share now, without rebooting,

sudo mount /media/samba_share

You can unmount the share with :

sudo umount /media/samba_share

If you wish to increase security at the expense of convenience, use this line in /etc/fstab

//myserver_ip_address/myshare /media/samba_share cifs noauto,credentials=/etc/samba/user,noexec 0 0

The noexec” option prevents executable scripts running from the SMB share.

Edit /etc/samba/user, remove the password (leave just the samba user).

Now the share will NOT automatically mount when you boot and you will be asked for your samba password.

Mount the share with :

sudo mount /media/samba_share

CIFS may cause a shutdown error.

CIFS VFS: Server not responding.

There is a fix in the troubleshooting section of this forum post.

Connecting using SMBFS (deprecated)

Note: This method still works, but as outlined under the “CIFS” section above is “deprecated” (no longer maintained and pending removal from the kernel).

Mounting a share on the local filesystem allows you to work around programs that do not yet use GnomeVFS to browse remote shares transparently. To mount a SMB share, first install smbfs:

sudo apt-get update
sudo apt-get install smbfs

To allow non root accounts to mount shares, change the permissions on the smbmnt program thus:

sudo chmod u+s /usr/bin/smbmnt /usr/bin/smbumount

Note: This may be a security risk as after setting the SUID bit anyone can mount a SMB share. I advise you configure sudo, as above.

The working line in /etc/sudoers is as follows (see CIFS section above):

%samba ALL=(ALL) /bin/mount,/bin/umount,/sbin/mount.cifs,/sbin/umount.cifs,/usr/bin/smbmount,/usr/bin/smbumount

This allows any user in the samba group to mount SMB shares (you will need to create a samba group and add users).

The following will mount the myshare folder on myserver to ~/mnt (it will be in your home directory):

mkdir ~/mnt
smbmount //myserver/myshare ~/mnt

To umount,

smbumount ~/mnt

In order to have a share mounted automatically every time you reboot, you need to do the following:

Open a shell as root

sudo -s

Create a file containing your Windows/Samba user account details:

vi /etc/samba/user

…it should contain two lines as follows:

username=george
password=secret

Change the permissions on the file for security:

chmod 0600 /etc/samba/user

Now create a directory where you want to mount your share (e.g. /mnt/data):

mkdir /mnt/data

Now edit the file system table (/etc/fstab) and add a line as follows:

//server/share /mnt/data smbfs credentials=/etc/samba/user,rw,uid=bob 0 0

…where ‘bob’ is the non-root user you log into ubuntu with, ‘server’ is the name or address of the Windows machine and ‘share’ is the name of the share.

To mount the share now, just use the following command as root. It will mount automatically on subsequent reboots.

mount /mnt/data

Ubuntu Client

On the Ubuntu client using the menu at the top, go to “Places” -> “Network”. You will see an icon “Windows network” and should be able to browse to your shared folder. You will be asked for a password, leave it blank. Click the “Connect button.

(no need for a password).

If you would like to mount your SMB share using your (server) hostname rather than the IP Address, edit /etc/hosts and add your samba server (syntax IP Address hostname).

192.168.1.100 hostname

Where “hostname” = the name of your samba server.

Windows Client

On Windows open “My Computer” and navigate to “My Network Places”. Navigate to your Ubuntu server and your share will be available without a password.

Alternate : From the menu at the top select “Tools” -> “Map Network Drive”. Select an available letter for your SMB share (Default is z: ). In the “Folder:” box enter samba_server_ipaddressshare. Tic (Select with the mouse) the option “Reconnect at login” if you want the share to be automatically mounted when you boot Windows. Click the “Finish” box. A dialog box will appear, enter your samba user name and password. Click “OK”.

If you would like to mount your SMB share using your (server) hostname rather than the IP Address, edit C:WINDOWSsystem32driversetchosts and add your samba server (syntax IP Address hostname).

192.168.1.100 hostname

Where “hostname” = the name of your samba server. Back to top
Samba Server Configuration – Graphical

Note: For Ubuntu 8.04 (Hardy) and later, shared folders are created directly from the folder. Browse to the location of the folder you would like to share, right-click the folder, and choose Sharing Options. Click the Share this folder.

This section should allow you to “quick start” SMB shares between Ubuntu and either Ubuntu or Windows servers. The gui method is easier to work with, because:

1. Shares are Public (browsable in Network Places)
2. A password is not set for shares (they can be mounted by anyone).

However, remember that this is less secure.

Be warned you are installing a service (server) and you may wish to install a Firewall management utility to help prevent undesired access. See also the manual configuration sections below to learn how to “hide” your shares from browsing and set a password for access.

Ubuntu Server

This section enables Ubuntu as a samba file server.

Sharing a Folder

To share a directory you must have permission to access the directory. Go to your home directory ( Places -> Home folder). Right click on the “Documents” directory and in the pop up menu select “Share Folder”.

If samba is not installed you will get a pop up menu “Sharing services are not installed”. Select “Install Windows networks support (SMB)” and deselect “Install Unix networks support (NFS)” -> then click “Install services”.

If you get an error message that the samba .deb could not be found, open a terminal and update apt-get.

sudo apt-get update

Try again and Ubuntu will download and install samba. Right click on the “Documents” directory and in the pop up menu select “Share Folder”. You will get a pop up menu “Share Folder”. Select “Windows networks (SMB)” in the pull down menu and give your share a name in the “Name” box. Unselect the “Read only” check box if you want read/write access to the share. Click the “Share” button.

Windows XP Server

This section enables Windows XP as a samba file server.

Sh
aring a Folder

1. On the Windows server, browse in explorer (“My Computer”) to the location of the folder you wish to share (C:Documents and Settings for example). Next right click on the folder to share and select “Sharing and Security…”. In the pop-up dialog box click the “Sharing” tab. Click the “Network Setup Wizard” to configure your network to allow shares. Work your way through the wizard. Note the default workgroup is MSHOME. You may change this value if you like but all your computers should be in the same workgroup. Eventually you will be given the option to “Turn on file and printer sharing”. This is the option you want, continue with the network wizard. You will have to restart your computer for the settings to take effect -> Restart Windows.

2. After rebooting, again open explorer (“My Computer”) and navigate to the folder you wish to share. Again right click on the folder and select “Sharing and Security…”. In the pop-up dialog box click the “Sharing” tab. In the “Network sharing and security” box, tic (select with the mouse) the “Share this folder on the network” box. Give the folder a share name. This will give read only access to Ubuntu computers via samba. To allow read/write access tic (select with the mouse) the “Allow network users to change my files” box. Click the “Apply” button and close the dialog box.

Samba Server Configuration – Manual

Configuration is performed by reading and editing /etc/samba/smb.conf, the configuration file for the samba server.

There are a few graphical tools available such as “kdenetwork-filesharing” and “Swat”.

A fairly comprehensive graphical Samba configuration tool is available for KDE, by installing the “kdenetwork-filesharing” package. Once install, you can find it by launching the KDE Control Center. (Alt-F2 and then type kcontrol). Browse to Internet & Network > Samba. It is fairly easy to use.

A less friendly but also graphical tool is Swat, a web-based interface.

The following tips show how to do some basic things without installing additional software, using the command line. It is not difficult, just be careful with typos.

First open a terminal: Applications > System Tools > Terminal and open the file smb.conf

sudo nano -w /etc/samba/smb.conf

How to Save: To save in nano use “CTRL-O”, then “CTRL-X”.

Tip: Replacing nano with gedit gives you a nice graphical editor.

The file *smb.conf* is divided in several sections:

Global Settings
Debugging/Accounting
Authentication
Printing
File sharing
Misc
Share Definitions

Comments may start with either a # or a ;

Global Settings

Let’s start with Global Settings. Here you will see several lines, which you can also see in the graphical networktool like workgroup and wins server. If you changed everything to your liking already then you can skip this section, if not change to what you need. If you do not know what items mean, leave them be and read the relevant part in the real Samba-howto instead of randomly changing them. It will save you trouble-shooting later.

File Sharing (Basics)

The important part for us is File sharing. Samba shares are named in brackets, [ ], and configured by adding options in the lines that follow. Most options are boolean (yes / no).

We need to change:

[homes]
comment = Home Directories
browseable = no

# By default, the home directories are exported read-only. Change next
# parameter to ‘yes’ if you want to be able to write to them.
writable = no

This describes your /home folder. Usually you want to share this folder in a home-environment, because these are the files you want to share. To do so, make the following changes:

[homes]
comment = Home Directories
browseable = yes

# By default, the home directories are exported read-only. Change next
# parameter to ‘yes’ if you want to be able to write to them.
writable = yes

This finishes sharing your /home folder. The last thing we need to do is fixing a user.

Add users who can access your shares with the ‘smbpasswd’ command.

sudo smbpasswd -a username

New SMB password:
Retype new SMB password:
Added user username.

NOTE: the username used here should be a real user setup on your PC/Server. Reload Samba for every change to users/passwords or ‘smb.conf’

sudo /etc/init.d/samba reload

That’s the basis of Samba file-sharing. Please leave your comments about what else is needed here.

* Can/should the SMB password be different from the user’s system password? MartinSpacek – 2007-11-19

File Sharing (Advanced)

We started with the base of Samba file-sharing. The above-mentioned items should be enough to get you started. Next we will add details that you might or might not need.

If you have more than one network card

If you have more than one network card (or interface) then you have to define where you want Samba to run. In smb.conf under the [global] section, add:

interfaces = 127.0.0.1, 192.168.0.31/24
bind interfaces only = yes

The first address (127.0.0.1), is a loopback network connection (it’s your own machine). The second address (192.168.0.31), is the address of the card you want Samba to run on, the second number (24) is the subnet default for a CLASS-C network. It may vary depending on your network.

With “bind interfaces only” you limit which interfaces on a machine will serve SMB requests.

You can limit which IP address can connect to your Samba server adding these lines:

hosts allow = 127.0.0.1, 192.168.0.31, 192.168.0.32
hosts deny = 0.0.0.0/0

The loopback address must be present in the first line. The second line deny access from all IP address not in the first line.

Private and public shares in same config

First you’ll want to set this up in the [global] section of your smb.conf

[global]
security = user
encrypt passwords = true
map to guest = bad user
guest account = nobody

security = user restricts logins to users on your server. encrypt passwords = true is necessary for most modern versions of Windows to login to your shares. map to guest = bad user will map login attempts with bad user names to the guest account you specify with guest account = nobody. That is, if you attempt to login to the share with a user name not set up with smbpasswd the you will be logged in as the user nobody.

Next the private share

[private]
comment = Private Share
path = /path/to/share/point
browseable = no
read only = no

If browsable is set to no the share will not show up on graphical browsers such a “My Network Places” on Windows or Places -> Network on Ubuntu.

path is the path to the directory that you want to share out. browseable = no will have the share not show up when users browse the network. read only = no will let you, as an authenticated user, write to the share.

Finally, the public share

[public]
comment = Public Share
path = /path/to/share/point
read only = no
guest only = yes
guest ok = yes

Again, path is the path to the di
rectory that you want to share out. read only = no will allow users to write to this share. guest only = yes and guest ok = yes will allow guest logins and also force users to login as guests. The user you specified with guest account in the [global] section must have write permissions on /path/to/share/point in order to write files to the share.

Note: When Windows attempts to access a SMB share it will use the current Windows user name and password. The map to guest = bad user trick above allows access to the public share only if you give Samba an incorrect user name. If you give it a valid user name, but a bad password, the login will fail and Windows will give you a password prompt when you try to access the share. If you have the same user name for your Windows machine and your Ubuntu machine, you could be unwittingly giving the Samba server a valid user name, but invalid password. To resolve this you will either have to change the Windows user name, or to remove that user name from the Samba password file with sudo smbpasswd -x [username].

Note: The above uses security = user. To access the private shares you will have to make sure the user exists in smbpasswd. These users must also already exist as normal users on your machine. You add users to smbpasswd simply by running sudo smbpasswd -a [username] and giving a password.

Setting permissions

To set permissions of newly created documents / files edit /etc/samba/smb.conf and in the [global] section add :

create mask = 0644
directory mask = 0755

Sharing CUPS Printers

Graphical Configuration

Setup Ubuntu Print Server

1. In your menu go to System -> Administration -> Printing
2. Under “Local Printers” on the left, select the printer you wish to share. Select the “Policies” tab on the right and make sure the “Shared” box is selected.

Ubuntu Client

1. Again go to System -> Administration -> Printing
2. Click “New Printer” in the upper right. In the next menu select “Windows Printer via SAMBA”. Now enter your Ubuntu Samba Print Server (set up as above) IP address in the box on the left titled “smb://”. Click the “Browse” button.
3. Select the printer in the “SMB Browser” window (Click on the little arrows). Once you have selected your printer, check the “Authentication required” and enter your samba user name and password. Then click the “Verify” button. You should see confirmation that the share is available.
4. Click the “Forward” button and install the drivers for your printer as you would for any other printer.

Windows Client

1. Go to Control Panel -> Printers
2. Click “Add a printer” on the upper left. The printer wizard will start -> click forward. Select Network Printer and click “Next”. Select “Browse for a printer” (Top button) and click “Next”. In the next window, navigate to your Ubuntu Samba Print Server and click “Next”. Continue with the printer and driver installation.

Manual Server Configuration

If You would like to share Your printers make the following changes to Samba:

If not already done create the Samba-user You want the share to be used by.

In smb.conf uncomment and change the lines ending up with the following configuration:

########## Printing ##########

# If you want to automatically load your printer list rather
# than setting them up individually then you’ll need this
load printers = yes

# [...] // Some BSD printing stuff, do not edit if You do not need to

# CUPS printing. See also the cupsaddsmb(8) manpage in the
# cupsys-client package.
printing = cups
printcap name = cups

and in the Share Definitions section append and/or modify the [printers] part ending up like this:

# ======================= Share Definitions =======================
# [...] // File and Folder sharing, do not edit if You do not need to

[printers]
comment = All Printers
browseable = no
path = /tmp
printable = yes
public = yes
writable = no
create mode = 0700
printcap name = /etc/printcap
print command = /usr/bin/lpr -P%p -r %s
printing = cups

Some explanation what is done:

the [printers] part defines the default-behavior for all the printers that are mentioned in “printcap name”. A sort of template how to create shares for these printers. This template is applied if “load printers” is set to true. For more detailed explanation refer to the Samba documentation.

And do not forget to reload Samba:

sudo /etc/init.d/samba reload

Securing Samba

This section was started to give some general advise on security considerations and is not an exhaustive review of samba security.

/etc/samba/smb.conf

* Networking Section – use “hosts allow” and “hosts deny”

# hosts allow = 127.0.0.1 192.168.1.0/24
hostal allow = 127.0.0.1 192.168.1.1 192.168.1.2
hosts deny = 0.0.0.0/0

* hosts deny 0.0.0.0/0 = all others.

* Shares
o When defining a share, consider the following options :
1. browseable = no ~ Shares will not show up when browsing your network.
2. users = user1 user2 ~ List of users able to access the share

When setting up a Samba share, you can limit the users who have access to your share

[private]
comment = Private Share
path = /path/to/share/point
browseable = no
read only = no
valid users = user1 user2 user3

Now only samba users user1, user2, and user3 will have access to the share “private”.

Firewall

Configure your firewall (iptables) to limit access to your server. Samba uses ports

* UDP ports 137 and 138
* TCP ports 139 and 445

Edit Smb.conf

sudo nano -w /etc/samba/smb.conf

Reload Samba

sudo /etc/init.d/samba reload

In smb.conf in section [general] add this command to share folder wth another operating system :

usershare owner only = false

source : ubuntu.com

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