Kodi and SMBv1 – how to jump into the 21st century

Kodi logo

What is it?

The Server Message Block (SMB) protocol is a network file sharing protocol that allows applications on a computer to read and write to files and to request services from server programs in a computer network. The SMB protocol can be used on top of its TCP/IP protocol or other network protocols. Using the SMB protocol, an application or the user can access files or other resources at a remote server. This allows applications to read, create, and update files on the remote server. It can also communicate with any server program that is set up to receive an SMB client request.

What versions are out there?

The original SMB1 protocol is nearly 30 years old, and like much of the software made in the 80’s, it was designed for a world that no longer exists.

The SMBv2 protocol was introduced in Windows Vista and Windows Server 2008. The SMBv3 protocol was introduced in Windows 8 and Windows Server 2012.

WannaCry

Almost everyone has heard of WannaCry in the recent weeks, an exploit that propagates EternalBlue, made by the NSA and lost by the NSA, an exploit of Windows’ Server Message Block (SMB) protocol.

WannaCry is made less harmful by patching Microsoft’s Operating Systems, disabling SMBv1 and blocking all versions of SMB at the network boundary by blocking TCP port 445 with related protocols on UDP ports 137-138 and TCP port 139, for all boundary devices.

 

How to enable or disable SMB protocols on the Windows SMB server

If you are running Windows Server you can use the Set-SMBServerConfiguration Windows PowerShell cmdlet. The cmdlet enables you to enable or disable the SMBv1, SMBv2, and SMBv3 protocols on the server component. You do not have to restart the computer after you run the Set-SMBServerConfiguration cmdlet.

To obtain the current state of the SMB server protocol configuration, run the following cmdlet:

Get-SmbServerConfiguration | Select EnableSMB1Protocol, EnableSMB2Protocol

To disable SMBv1 on the SMB server, run the following cmdlet:

Set-SmbServerConfiguration -EnableSMB1Protocol $false
Notes
  • You must run these commands at an elevated command prompt.
  • You do not have to restart the computer after you make these changes.

 

To enable or disable SMB protocols on an SMB Server that is running a Windows Desktop OS use Windows PowerShell or Registry Editor.

To disable SMBv1 on the SMB server-side, run the following cmdlet:

Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters" SMB1 -Type DWORD -Value 0 -Force
Notes
  • You must run these commands at an elevated command prompt.
  • You must restart the computer after you make these changes.

 

How to enable or disable SMB protocols on the Windows SMB client

Note

You might think a Windows Server has nothing to do with the client side of SMB but it uses the client to connect to other servers. So if you want to completely disable SMBv1 you also need to do the following on the Server OS.

To disable SMBv1 on the SMB client, run the following commands:

sc.exe config lanmanworkstation depend= bowser/mrxsmb20/nsi 
sc.exe config mrxsmb10 start= disabled
Notes
  • You must run these commands at an elevated command prompt.
  • You must restart the computer after you make these changes.

 

How to gracefully remove SMBv1 in Windows 8.1, Windows 10, Windows 2012 R2, and Windows Server 2016

If you are sure you do not need SMBv1 and will never need it you can also remove it from the OS.

If you are using Windows Server run the following cmdlet:

Remove-WindowsFeature FS-SMB1

If you are using a Windows Client IS run the following cmdlet:

Disable-WindowsOptionalFeature -Online -FeatureName smb1protocol
Note
  • You must run these commands at an elevated command prompt.

 

 

When does Kodi come into play?

You might have read this so far and asked yourself what has this to do with Kodi? Well after I disabled SMBv1 on my free Microsoft Hyper-V Server 2016 (Blog Post coming soon) I noticed my OSMC Kodi client couldn’t access the libraries anymore.

That’s weird, OSMC is running a fairly new Linux kernel and is normally shipped with up to date packages. Samba 3.6 was the first version that made SMBv2 possible. Released at the end of 2011 this should have worked.

After a lot of time on the Kodi and OSMC forum it turns out that Kodi has some sort of its own smb configuration.

While normal Linux systems have the configuration file located in the /etc/samba/smb.conf file, it turns out that Kodi uses it own configuration file.

While bumping the system wide smb.conf file for Samba up to SMB2 or higher I was still unable to connect my Pi with OSMC to my Ubuntu Server running SMB3.

Using smbstatus you can get a report on current Samba connections

$ sudo smbstatus -b

The almost hidden .smb/smb.conf

Kodi has very poorly documented its own smb.conf file in the ~/.kodi/.smb/smb.conf location. This is the file that Kodi uses for its Samba configuration.

I started adding the option client min protocol = SMB2 to bypass SMB1. After this I still couldn’t make a connection with my files. Some people stated client max protocol = SMB3 should go along with the min setting. I also added client NTLMv2 auth = yes since this kinda is the default settings since Windows Server 2008.

After this I was able to connect with my Windows Server 2016 but still not with my Ubuntu Server. I downgraded the server protocol to SMB2 with server min protocol = SMB2 and things started to work.

$ sudo smbstatus -b

Samba version 4.3.11-Ubuntu
PID Username Group Machine Protocol Version
------------------------------------------------------------------------------
1741 nobody nogroup 172.16.1.195 (ipv4:172.16.1.195:50393) Unknown (0x0311)
1758 nobody nogroup 172.16.1.187 (ipv4:172.16.1.187:47632) SMB3_00
1758 -1 -1 172.16.1.187 (ipv4:172.16.1.187:47632) SMB3_00

Nice to see the client is connecting with SMB3 while it wouldn’t connect while the server was on SMB3 level… interoperability… jeej! 😉

So after some time I ended with the following configuration file for my Linux computers:

smb.conf

[global]
 client min protocol = SMB2
 client max protocol = SMB3_11
 client NTLMv2 auth = yes
 server min protocol = SMB2

 

After-effects

Disabling SMBv1 in Kodi breaks the SMB browsing function. You will not be able to use the SMB browser to navigate through your network and shares. If you want to connect to a new source you will have to type smb://MyServer/MyShare/

Android Phones/Tables/Players will not be able to make use of the more secure servers. While the same mechanism is still there the Samba client shipped with Kodi is not able to connect to SMB2/3 shares. According a developer from Kodi their Samba version for Android is not compatible with it.

Android/data/org.xbmc.kodi/files/.smb/smb.conf

A bit snooping arround github shows they are probably using Samba 3.0 with a lot of patches. The good news is that three weeks ago they started some work with Samba 4.1.

Until that work is complete a workaround for Kodi on Android might be switching to NFS or going truly hardcore with mounting cifs on the Android system.

Windows Server 2016 docs are now on docs.microsoft.com

Windows Server logo

Microsoft announced the availability of the IT pro technical documentation for Windows Server 2016 and Windows 10 and Windows 10 Mobile on docs.microsoft.com.

docs.microsoft.com?

Docs is a crisp new design that should work better on your phone, tablet, and PC. You’ll see new ways to engage with Microsoft and contribute to the larger IT pro community on docs.

Performance Tuning Guidelines for Windows Server 2016

When you run a server system in your organization, you might have business needs not met using default server settings. For example, you might need the lowest possible energy consumption, or the lowest possible latency, or the maximum possible throughput on your server. This guide provides a set of guidelines that you can use to tune the server settings in Windows Server 2016 and obtain incremental performance or energy efficiency gains, especially when the nature of the workload varies little over time.

It is important that your tuning changes consider the hardware, the workload, the power budgets, and the performance goals of your server. This guide describes each setting and its potential effect to help you make an informed decision about its relevance to your system, workload, performance, and energy usage goals.

Warning

Registry settings and tuning parameters changed significantly 
between versions of Windows Server. Be sure to use the latest 
tuning guidelines to avoid unexpected results.

You can download the official document here.

Windows 10, Hyper-V and Wireless – Yes, Hyper-V also can do NAT

Set up a NAT network

Windows 10 Hyper-V allows native network address translation (NAT) for a virtual network.

This guide will walk you through:

  • creating a NAT network
  • connecting an existing virtual machine to your new network
  • confirming that the virtual machine is connected correctly

Requirements:

  • Windows 10 Anniversary Update or later
  • Hyper-V is enabled
Note: Currently, you to create one NAT network per host.

Continue reading Windows 10, Hyper-V and Wireless – Yes, Hyper-V also can do NAT

Giving a Workgroup Server an FQDN

You might need to be able to securely, remotely manage a set of Windows Servers that are not domain joined. One problem that you may hit while remotely managing this is that the server does not believe that it has a valid FQDN.

For example

  • Set the name of a computer to “Server1”
  • Create a DNS entry that said that “Server1.mydomain.local” resolved to that computer
  • You can then correctly ping the computer at that address

But when you trie to use tools like PowerShell Remoting or Remote Desktop – they would complain that “Server1.mydomain.local” did not believe it was “Server1.mydomain.local”.

Thankfully, this is relatively easy to fix.

If you open PowerShell and run the following two commands:

Set-ItemProperty "HKLM:\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\" -Name Domain -Value "mydomain.local"
Set-ItemProperty "HKLM:\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\" -Name "NV Domain" -Value "mydomain.local"

After this your workgroup server will correctly identify itself with a valid FQDN.

How to avoid storage network overload with Storage QoS

Every systems administrator who manages I/O intensive workloads is acutely aware of the problems that happen when storage controllers become overloadedapplications come to a screeching halt.

This is especially problematic for database administrators managing busy transactional workloads across multiple virtual machines. When storage devices come under load, you need to be able to utilize every available IOPS to maximize performance.

Windows Server 2016 with Storage Quality of Service (QoS) offers greater control over how you reserve IOPS for each virtual machine, enabling you to make more efficient use of storage bandwidth across virtual machines. Admins can set not only the maximum IOPs limit for each VM, but in a feature unique to Windows Server 2016, they can also set the minimum IOPs that should be allocated for each VM. This level of fine-tuned control means IT can optimize the performance of all available storage resources. Take a look at this brief demo:

Storage QoS offers two important advantages: 1) it helps you to get more bang for your storage buck by better utilizing the storage you already own, and 2) it makes storage performance more reliable, even for workloads with uneven traffic across virtual machines.

windows-server