Belkin F5D8053 Support in Ubuntu – Drivers from Nowhere

New Hardware

I recently purchased a new wireless ADSL router, which came with a USB WiFi network adapter. Being a fairly new release of the hardware the kernel didn’t recognize it and I couldn’t use it.

However, after some research I found that it is in deed supported by the kernel – but just not recognized due to a change in the hardware ID reported by the device. The kernel module it should work with is the RT2870 driver.

If this is the case, it should be easy to fix.

Making it Work

If you have recently rebuilt your kernel you can skip section (A), and simply proceed with (B) and (C).

A. Preparing Build Environment

The steps for preparing the build environment is based on those needed for Ubuntu 10.04 (Lucid Lynx). If you have problems building the kernel after following these steps (especially for older versions of Ubuntu), see Kernel/Compile for instructions more tailored to your version of Ubuntu.

1. Prepare your environment for building

   sudo apt-get install fakeroot build-essential
   sudo apt-get install crash kexec-tools makedumpfile kernel-wedge
   sudo apt-get build-dep linux
   sudo apt-get install git-core libncurses5 libncurses5-dev libelf-dev 
   sudo apt-get install asciidoc binutils-dev

2. Create and change into a directory where you want to build the kernel
3. Then download the kernel source:

   sudo apt-get build-dep --no-install-recommends linux-image-$(uname -r)
   apt-get source linux-image-$(uname -r)

4. A new directory will be created containing the kernel source code. Everything else should happen from inside this directory

B. Modifying the Source

1. Run lsusb and look for your Belkin device. It should look something like this

   Bus 002 Device 010: ID 050d:815f Belkin Components

2. Note the hardware identifier, which in the above example is 050d:815f. Save this value for later.
3. Inside the kernel source, edit the file drivers/staging/rt2870/2870_main_dev.c
4. Search for the string Belkin. You should find a few lines looking like this:

     { USB_DEVICE(0x050D, 0x8053) }, /* Belkin */
     { USB_DEVICE(0x050D, 0x815C) }, /* Belkin */
     { USB_DEVICE(0x050D, 0x825a) }, /* Belkin */

5. Duplicate one of these lines and replace in the ID noted in (3) above. Split and adapt the format of the 2 parts on either sides of the colon to conform to the syntax used in the lines from (4). In my example the 050D:815F would end up with a line as follows:

     { USB_DEVICE(0x050D, 0x815F) }, /* Belkin */

6. Save the file and proceed to (C)

C. Rebuilding and Reinstalling the Kernel

1. Run the following command in the kernel source directory:

   AUTOBUILD=1 NOEXTRAS=1 fakeroot debian/rules binary-generic

2. This command will take a few minutes to complete. When it’s done you’ll find the kernel image .deb files one level up from the kernel source directory.
3. To update your kernel image, you can install these using dpkg. For example:

   sudo dpkg -i linux-image-2.6.32-21-generic_2.6.32-21.32_i386.deb

4. After installing, reboot your system and the device should be working.

Conclusion

Hardware manufacturers change the device IDs for various reasons, mainly when changes were made to the device that requires distinguishing it from previous releases (for example new functionality added to an existing model). A driver will always have a list of devices with which is it compatible. Sometimes the changes made by the manufacturer doesn’t really change the interface to the device, which means previous drivers would work perfectly fine had they known they are able to control the specified device.

The change above was exactly such a case where the driver is able to work with the device, but doesn’t know it supports this exact model. So all we did was to find the hardware ID actually reported by the device and add this to the list of IDs the driver will recognize and accept.

This is a great thing about Linux and the common Linux distributions. Almost all (if not all) packages you’ll find in your distribution are open source and make it possible to change whatever you need changing. Had this not been the case we would have needed to wait for whomever maintained the drivers to supply us with a version that would identify this device, where the existing drivers could have worked perfectly fine all along.

So in this case, it was like getting a driver for the device out of thin air.

Further, even if you spent time researching it and the change didn’t work, if you’re like me you’ll be just as excited as if it did work as now you can spent time figuring out why it didn’t work. This is actually the case with me, where the change didn’t make my device work. So I’m jumping straight in and fixing it. Will update when I get it working.

So Why Love Linux? Because by having the source code to your whole system available, you have complete freedom and control.

The Traveling Network Manager

Overview

Networks are such a big part of our lives these days that being at a place where there isn’t some form of a computer network, it feels like something’s off or missing, or like it wasn’t done well. You notice this especially when you travel around with a device capable of joining WiFi networks, like a smartphone, tablet or laptop. And even more so when you depend on these to get internet access.

Ubuntu, and I assume most modern desktop distributions, come with a utility called NetworkManager. It’s this utility’s job to join you to networks and manage these connections. It was designed to make best attempt to configure a network for you automatically with as little user interaction as possible. Even when using the GUI components, all input fields and configuration UIs were designed to make managing your networks as painless as possible, keeping in mind the average user’s abilities. All complicated setup options were completely removed, so you can’t configure things like multiple IP addresses, or select the WiFi channel, etc.

NetworkManager is mostly used through an icon in the system tray. Clicking this icon brings up a list of all available networks. If you select a network, NetworkManager will attempt to connect to the network and configure for your device via DHCP. If it needs any more information from you (like for a WiFi pass phrase or SIM card pin code), it will prompt you. If this connection becomes available in the future it will then automatically try and connect to it. For WiFi connections it’s the user’s job to select the first connection from the menu. For ethernet networks NetworkManager will automatically connect the first time.

These automatic actions NetworkManager takes are to make things more comfortable for the end user. The more advanced user can always go and disable or fine tune these as needed. For example to disable automatically connecting to a certain network, or setting a static IP address on a connection.

Roaming Profiles

If you travel around a lot you end up with many different network “profiles”. Each location where you join a network will have it’s own setup. If all these locations have DHCP you rarely need to perform any manual configuration to join the network. You do get the odd location, though, where you need some specific configuration like a static IP address. NetworkManager makes this and roaming very easy and natural to implement, and seamlessly manages this “profile” for you.

You would do this by first joining the network. Once connected, and whether or not your were given an IP address, you would open the NetworkManager connections dialog and locate the connection for the network you just joined. From here you would edit it and set your static IP address (or some other configuration option) and save the connection.

By doing this you effectively created your roaming profile for this network. None of your other connections will be affected, so whenever you join any of your other networks, they will still be working as they did previously, and the new network will have it’s own specific configuration.

This was never really intended to be a roaming profile manager, so other options related to roaming (like proxy servers) will not be configured automatically. I’m sure with a few scripts and a bit of hacking you should be able to automate setting up these configurations depending on the network you’re joining.

Conclusion

NetworkManager is maybe not the advanced user’s favorite tool. But if you don’t need any of these advanced features I would certainly recommend it.

So Why Love Linux? Because NetworkManager does a brilliant job of making networking comfortable in a very natural way.

Playing Ping Pong with ARP

ARP

Let me start of by giving a very rough explanation of how devices communicate on ethernet and WiFi networks. Each network device has a unique hardware address called a MAC address. These are assigned by manufacturers and don’t change for the life of the device. Many manufacturers even place the address on a sticker on the chip. It is possible to change the address with software, though the idea is that the address remain static so the device can communicate on a physical network.

So what happens when you want to connect to a machine on your local network? Assume your IP is IP-A and your destination is IP-B. Your computer will first do what is called an “ARP who-has” broadcast, asking everyone on the network to identify themselves if they are the owner of IP-B. The owner of IP-B will then respond to you saying, “I am IP B, and I’m at this MAC address”. After this response both machines know at which physical address each other is, and are able to send and receive data to and from each other.

Now, the protocol for discovering the MACs as I described above is called ARP, the Address Resolution Protocol. You can get a listing of the known MAC addresses of devices you’ve been communicating with on your LAN by running the following command:
arp -an

Ping

So, everyone probably knows the ping command. It’s a command that sends a packet to another machine requesting a response packet. It’s often used to test if a machine is up, whether an IP is in use, to measure latency or packet loss, and so on. It’s very simple to use. You simply run ping <ip address> and on Linux it will then continuously send ping or echo requests and display any responses. When you abort the command with Ctrl+C you will also get a summary of the session, which includes the numbers of packets sent, the packet loss percentage, the elapsed time and some other metrics.

Though because of security concerns many people disable ping and it’s not always possible to use it for a quick test to see if a host is up and behind a certain IP address. Sometimes I just need a temporary IP on a specific subnet, and ping alone isn’t enough to quickly determine if an IP is currently claimed.

This is where arping comes in. arping is a very handy utility that does basically the same as ping, except with arp who-has packets. When you run it against a given IP address, it will send arp who-has packets onto the network, and print the responses received.

Here is some example output of arping:
[quintin@printfw ~]$ sudo arping 10.0.1.99
ARPING 10.0.1.99 from 10.0.1.253 eth0
Unicast reply from 10.0.1.99 [7B:F1:A8:11:84:C9] 0.906ms
Unicast reply from 10.0.1.99 [7B:F1:A8:11:84:C9] 0.668ms
Sent 2 probes (1 broadcast(s))
Received 2 response(s)

What’s the Point

This is useful in many cases.

1. Ping is not always available, as some system firewalls actively block it, even to other hosts on it’s LAN. In there cases you can still do a hosts-up test.
2. You can do it to quickly discover the MAC address behind a given IP.
3. If you have an IP conflict you can get the MAC addresses of all the hosts claiming the given IP address.
4. It’s a quick way to see if a host is completely crashed. If it doesn’t respond to ARP it’s very dead.
5. You can ping hosts even if you’re not on the same subnet.

I’m sure one can find many more uses of arping. I think it’s a very useful utility.

Windows Firewall Oddities

On a side note I thought might be interesting. I have noticed some people with the AVG Anti-Virus package’s firewall to not respond to ARP requests all the time. I haven’t investigated it further, though it seems like it will prevent sending responses in certain scenarios. This is definitely a feature that I would prefer didn’t exist, though am sure there are benefits to it, like being in complete stealth on a LAN. When I find out more about this, I’ll update this page.

Conclusion

So Why Love Linux? Because it comes preinstalled with and has available to it tons of ultra useful utilities and programs.