qMp (Quick Mesh Project) - Packages

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h1. Virtualbox

It is possible to emulate qMp with Virtual Box.

First of all open your virtualbox (VB) and create a new machine (type linux 2.6).

If you are using the VB wizard, do not select any storage device, we will do it latter.

h3. Storage

To make the things easy it is better to use IDE instead of SATA. 

Create a new IDE disk and browse between your foldersand select the qMp vdi image file.

The vdi file can be obtained here: http://fw.qmp.cat/testing with the name VBox-qMp_testing-factory-XXXXX.bin

It should be renamed to something such as VBox-qMp1.vdi

h3. Network Configuration

First of all we create a virtual tun/tap device in the host machine.

<pre>ip tuntap add mode tap dev vbox 

ip link set vbox up

ip addr add 172.30.22.10/24 dev vbox

</pre>

In VB machine configuration at least one network interface must be added.

It should be configured as bridged interface to our new "vbox" network device.

The driver "PCnet-PCI II" works fine.

h3. Serial

A serial port is needed because OpenWRT expects it. So it should be added in the VB machine configuration.

It is possible to use it to connect with the qMp node from the host machine (useful for debug), but it is NOT NEEDED.

To do so you should configure the VB serial as host pipe.

Check the option "create pipe" and add the path "/tmp/vboxS0".

Then in the host machine execute:

<pre>socat UNIX-CONNECT:/tmp/vboxS0 TCP-LISTEN:7777 &

netcat localhost 7777

</pre>

And you will get serial!

h3. Start VM

At this point you can start your virtual machine with qMp, open a browser and go to http://172.30.22.1

If after the first reboot (automatic reboot) it does not boot (stays in "GRUB LOADING") reboot manually the VM.

h3. Clone

Ok, but just one node is quite boring so let's go to create more of them. Just switch-off the virtual machine, right click and Clone it.

Select the option "regenerate MAC addresses", boot the new  machine and then execute:

<pre>rm /qmp_configured

/etc/init.d/qmp_autoconf start

</pre>

Then both nodes should see each other!

h1. QEMU

It is possible to use the same VirtualBox VDI image file. So again, you can get it from http://fw.qmp.cat

Copy it to somewhere and change the name to, for instance "qMp1.vdi".

Then just start QEMU:

<pre>sudo qemu -net nic,model=pcnet -m 64 -hda qMp1.vdi</pre>

You can add "-nographic" option and "-daemonize".

h3. Serial

Get serial is very easy, just add this option to QEMU

<pre>-serial pty</pre>

The qmeu will show you the pty device attached to the serial port of the virtual machine, then just use it:

<pre>screen /dev/pts/3</pre>

Amazing!

h3. Network

There are several ways to get the network working, I use the combo bridge+tap.

In the host machine we will have a bridge named "qemu" and the network interface of the virtual machine

will be a tap device attached to such bridge.

The next options must be added to the qemu exec command line

<pre>-net tap,ifname=qmp1</pre>

And these two scripts are needed:

*/etc/qemu-ifup*

<pre>

#!/bin/sh

if ! brctl show | grep qemu; then

	brctl addbr qemu

	ip link set qemu up

fi

echo "Executing /etc/qemu-ifup"

echo "Bringing up $1 for bridged mode..."

sudo /sbin/ip link set $1 up promisc on

echo "Adding $1 to br0..."

sudo brctl addif qemu $1

sleep 2

</pre>

*/etc/qemu-ifdown*

<pre>

#!/bin/sh 

echo "Executing /etc/qemu-ifdown"

sudo /sbin/ip link set $1 down

sudo /usr/sbin/brctl delif qemu $1

sudo /sbin/ip link delete dev $1

</pre>

And make them executable

<pre>chmod +x /etc/qemu-*</pre>

To reach the node it is needed to add an IP to the host machine bridge:

<pre>ip addr add 172.30.22.10/24 dev qemu</pre>

h3. Multiple nodes

Each virtual machine needs its own disk file, so copy the VirtualBox vdi image to, for instance "qMpv2.vdi".

You should use a new one, do not copy the image from another existing machine!

To skip the problem of duplicate MAC addresses, the option "macaddr" should be added to the previous net option.

<pre>-net tap,ifname=qmp1,macaddr=$(/etc/qemu-mac)</pre>

And another script is needed (make it executable too!)

*/etc/qemu-mac*

<pre>

#!/bin/sh

# generate a random mac address for the qemu nic

printf 'CA:FE:BA:BE:%02X:%02X\n' $((RANDOM%256)) $((RANDOM%256))

</pre>

I use this little script to launch all the virtual machines from a directory:

<pre>

#!/bin/sh

VMDIR="${1:-.}"

for IMG in $VMDIR/*.vdi

  do

	echo "Starting image $IMG"

	sudo qemu -net nic,model=pcnet,macaddr=$(/etc/qemu-mac) \

	-net tap,ifname=qmp$(($RANDOM%30)) -m 64 -hda $IMG -nographic -serial pty -daemonize

  done

</pre>

Example of execution:

<pre>

p4u@eni4c:~/virtual $ ls

qMp1.vdi  qMp2.vdi  qmpvirt.sh

p4u@eni4c:~/virtual $ sh qmpvirt.sh 

Starting image ./qMp1.vdi

Executing /etc/qemu-ifup

Bringing up qmp4306 for bridged mode...

Adding qmp13 to br0...

char device redirected to /dev/pts/5

Starting image ./qMp2.vdi

Executing /etc/qemu-ifup

Bringing up qmp21308 for bridged mode...

Adding qmp21 to br0...

char device redirected to /dev/pts/7

</pre>

A more advanced version of this scripts is attached as file to this article.