Sushant Projects: March 2015

Friday, 27 March 2015

Saturday, 21 March 2015

Stage 4: Connecting nodes with GVPN

This is stage 4:

Till now, we successfully connected 2 endpoints (Alice and Bob) over the internet using IPOP and SVPN controller.

But there are some disadvantages of SVPN, for example:

What if there many many participants, it will be inpractical for each node to add every other node as friend on the XMPP server.

Also, SVPN cannot be used directly for something like LAN gaming, this is because it employs network translation(to maintain friend relationships). This means for Bob Alice's IP is different from Alice's self IP. Or in other words the VPN is very personal and IP mapping is different for every person.

To avoid this we are gonna use GroupVPN.

All to All connectivity in GroupVPN

Step 1: Creating configuration file

This will be somewhat similar to config file from SVPN. But We are going to use ONLY ONE XMPP ID. This will solve our first problem (adding each node as friend).

For this task you can go through stage 2 and create a new XMPP jabber ID specifically for this purpose, or we can use Alice's JID.

I created a new XMPP JID called 'group_sushant@xmpp.jp'

Next create a config.json file in IPOP directory with the following contents for each of the participating nodes:
For Node 1

{
    "xmpp_username": "group_sushant@xmpp.jp",
    "xmpp_password": "****",
    "xmpp_host": "xmpp.jp",
    "ip4": "192.168.5.1",
    "ip4_mask": 24,
    "stat_report": true,
    "tincan_logging": 0,
    "controller_logging": "DEBUG"
}

For Node 2, same config file but {"ip4":"192.168.5.2"}
For Node 3, same config file but {"ip4":"192.168.5.3"}
and so on...

Remember, XMPP ID and Password should stay the same across all nodes.

Step 2 : Running IPoP

Run this on all the participating nodes
sudo sh -c './ipop-tincan-x86_64 1> out.log 2> err.log &'
Note: use "ipop-tincan-x86" in place of "ipop-tincan-x86_64" for 32-bit Ubuntu machine.
then
./gvpn_controller.py -c config.json &> log.txt &

Step 3: Check if connected

Run on any of the node to see the status of the network.
echo -e '\x02\x01{"m":"get_state"}' | netcat -q 1 -u 127.0.0.1 5800

If any of the nodes did not start GVPN controller than those nodes won't be visible.
But if they start, then their nodes are visible but 'Offline'

To bring them online, or to complete the connection run
$ ping 192.168.5.2 <ip of that node>
(wait for some time, when reply comes you can stop pinging with ctr+C)

Now run 'echo -e '\x02\x01{"m":"get_state"}' | netcat -q 1 -u 127.0.0.1 5800' again.
If you are getting something like this

then congratulations you have successfully created a GroupVPN.

You can see in the image that your IP is 192.168.5.2, and your peers IP is 192.168.5.1,( which in the case of SVPN , your IP was always 172.31.0.100)

Step 4: How to avoid pinging step

IPOP doesn't establish links right away, it checks whether that link is required (or someone is trying to communicate through that link). That's why when we ping, a link is established , and the node appears online.
This is very important in case of grid computers or clusters, where if a node is not required , the system should avoid the complexity of considering that node everytime.

But for applications LAN gaming we don't expect many nodes, therefore we can instruct IPOP to form the links right away, without us having to ping each link everytime.

To do this, its very simple just include the following in the configuration file:

{"on-demand_connection" : false,}

To stop the vpn run:

pkill ipop-tincan-x86_64

ps aux | grep gvpn_controller.py

kill <pid-of-gvpn-controller.py>

Friday, 20 March 2015

Stage 3: Remote access with SSH

Welcome to stage 3 :
Hi all, till now we have successfully established a VPN using IPoP.
Lets setup SSH so that Bob can remotely access Alice's computer!

Step 1 :Install SSH server

For those who don't know SSH (Secure Shell Script) allows you to access a system running a SSH server over a network. Say if Bob wants to remotely use Alice's computer, then Alice should start a SSH server. Alice will install ssh server by

$sudo apt-get install openssh-server

and check if it is running (this should result in a process id)

$pgrep sshd

Step 2: Bob logs in on Alice's computer

From stage 3, we know that for Bob, Alice's IP is 172.31.0.101
Bob log's in by using following command
$ssh 172.31.0.101
and enter Alice's password.

The result is Bob has successfully logged in Alice's computer over the internet.

To exit back to local session run

exit

Transferring Files

Bob can download files present on SSH server(Alice) to his local system by doing
$scp user@172.31.0.101:/path/to/localfile /path/to/Destinationfile

Stage 2: Connecting Bob And Carol with SVPN

This is stage 3 :
Previously..(with '24' soundtrack)
-IPoP was Installed
-Alice and Bob registered on XMPP server
-Alice and Bob are friends.

Social VPN

Alice friends with Bob and Carol, but Bob and Carol are not friends.

In this tutorial I am going to connect Alice and Bob through IPoP's SocialVPN controller. SocialVPN helps in creation of virtual private networks connecting an Internet users to their friend’s devices. It derives friend relationship from XMPP servers( That is why we added Alice and Bob as friends in the previous stage). Each user is in control of who their VPN connects to(for example Alice is friends with Bob and Carol, but Bob and Carol are not friends, in that case there will not be a VPN link between Bob and Carol).