Getting Started with Samba!

I’m writing this post with the idea of how I first learned about samba, and I intend to write this post as a reference for me or for someone to read it and understand the key concepts. This is not going to be a details step by step technical walkthrough, rather a post that’ll work to help better understand the key concepts.

But before we can delve into Samba and how it works, it’s important to understand

The most shortest history of Windows Networking wrt this post

Samba Mamba!

The daemons of the Samba Mamba

• NMBD Provides NetBIOS Name Resolution ( WINS ) and network browsing services

• SMBD The main SAMBA hot-shot daemon provides
  • file sharing
  • printer sharing
  • authentication services using the SMB protocol

• winbindd This is not a proper service on the windows side, but it’s a service on the linux side that provides a sort of bridge from Linux to Active Directory

• Samba This is a new daemon(not at the point of writing this post but relatively), simply called ‘Samba’ in Samba 4 that allows samba to assume KerberOS roles and act as an Active Directory Domain Services DC

Samba command line tools 101

• smbclient Connect to a file share, list contents, this is very much like a command line FTP client

• smbpasswd This manages samba’s local store of user accounts and passwords, so this is very important for stand-alone servers.

• testparm Checks the syntax of the configuraton file smb.conf

• wbinfo This utility is used to query the winbindd daemon. This is a diagnostic tool.

• smbmount A ‘client’ side program that mounts an SMB file system onto a mount point in the linux FileSystem. useful for when Linux is acting as a client, to mount the shared drive.

• smbstatus A program that reports the current network connections to the shares on a Samba server

• net A tool for administration of remote SMB/CIFS servers intended to resemble windows “NET” applications

A harmless file to know about

/etc/smb.conf

• This file is read by the smaba daemons and some comand line tools and is the MAIN configuration file for Samba

• It’s written using the old Windows ‘.ini’ format

• This is the configuration syntax type ; -> ; Sections contain name = value

• There’s a web based tool called SWAT ; Samba Web Administration Tool ( no longer suported for Samba4 )

Installing Samba sample

Some distrubitions contain client side samba packages like winbind, samba common , samba client etc.

To see rpm -qa | grep samba

Server components have to be installed

yum -y instlal samba samba-docs

^ This might not install Samba 4 but Samba 3 depending on the target system

• The Samba-doc packages has pretty nice PDF documents! look at those using rpm -ql samba-doc | less this will show you the contents of the package, including the PDF files

Creating and viewind a Samba file share! (finally…)

• in /etc/samba , the file smb.conf contains a lot of comments which can be useful to understand stuff!

• The [global] section of the file contains things that’ll affect the server as a whole!

Let’s set it like this

[global]
  netbios name = MAMBA-SERVER
  security = user # this means that authentication will happen based on credentials that are locally stored on the server itself.
  name resolve order = wins bcast # this might not be absoulte necessary, but again this keeps with traditions
  # if this is given like this, then we have explicitly removed DNS


[docs] # This is the name of the share
  comment = documentation # maybe this is called comment
  path = /usr/share/doc
  read only = yes
  # or it can be called writable = no with the same effect

The traditional NFS UNIX file sharing is different, in NFS the name which the clients see is exactly the path in the server but in Samba we can choose a different name, like the share name is ‘docs’ but the path is different.

• To test the syntax use testparam and simply run simply run testparam and it’ll read /etc/samba/smb.conf

• testparam in it’s output might add a new line like this in the global section idmap config * : backend = tdb this has got to do with how the user names and passwords will be saved on the server

• service smb start

• service nmb start

• lsof -i | grep '[sn]mbd' to see that the services are listening on TCP and UDP ports!

• if the firewall is enabled, disable it.

• We can use the program findsmb to find samba shares on the network, basically machines on the network that might correspond to SMB probes on the network.

• since in this example we used the line in smb.conf to contain only locally saved credentials, we have to make a password for a user in samba.
  That user must already exist as a user in the Unix OS itself

Try running smbpasswd -a vader then enter the SMB password for user vader to set the password for vader

• To view the shares, use the smbclient program as smbclient -L MAMBA-SERVER -U vader the -L is list on the net-bios server name with the user vader. Then enter vader’s password to see the share!

We see the docs share which defined and also a share called IPC which is Inter Process Communication and is something Samba uses internally , also we see the server name and the workgroups

• Finally, to connect to the server smbclient //MAMBA-SERVER/docs -U vader

will enter the smb: > command share prompt

This is similar to the FTP shell, so you can get and put files and also quit

• To see the samba status of what’s using what, use smbstatus to see the pid’s, service files etc.

• To connect / view the share on a windows on the same network,

  The MAMBA-SERVER is listed in the Network! We can see the docs machine and also have access to this share! You’ll most likely have to enter the credentials for the SMB share i.e those for Vader)

There’s also a web administration tool called SWAT Samba web Administration Tool, but it’s not supported in Samba 4, so I didn’t learn much about it which is why I can’t write about it. But you might come across something like this on legacy or older systems