TT’s Jottings-Blog of VU2SWX

I took a session on recycling old PCs with LTSP at   barcamp kerala 7 last Sunday.  Even though I am associated  with the organizers of barcamp ever since its inception in Kerala, I could not attend any of the previous ones due to various reasons. So I was a bit skeptical about the kind of people I may meet. Also, this was the first public lecture I gave after assuming charges of Principal College of Engineering Attingal. I  conveniently hid this fact from the audience suspecting that my job profile might overshadow the geek in me.

I was picked up from home by Kenney Jacob at 5.30 am  and we stated our journey to Changannasery on a TATA VISTA . The car was fantastic with GPS can other gizmos . A few of Kenney’s colleagues were also present in the car. We reached the  venue around 8.45 to find that the  gates of the Krishtu Jayanti college were closed. Kenny made some frantic telephone calls and finally we were asked to enter the college via  the  gates of a Catholic church.

There were around  70 guys in the hall. There was some initial hiccups and the  sessions took some time to start . I missed introductory remark by Kevin as I went to the nearest tea shop for a quick dose of coffee. The next session from Prassed Pai on 3d graphics programming was good and reminded me of my PG classes at CUSAT where we did all the shading and drawing algorithms. I think most of the audience was clue less about the topic.
The next session    Building Complex Website the Drupal Way from  Fredrik Jonsson? was   enlightening.
The third  session on Media by Kenney Jacob initiated some interesting discussions among the audience. Some of the participants expressed the fears about corporate media  manipulating facts .
Next was a cake cutting session . Some one suggested Fredrik Jonsson’s name for the event and every one clapped  when he cut the big cake sponsored by   ayruz web holdings  . Later I had lunch at a local teashop .
I took the first session in the after noon. My Idea was to set up my laptop as ltsp server and net book as the client . Then project the client to  the  big screen and start the presentation on the client.
The Sharp projector  at the venue was behaving erratically. It showed only half of the screen. I had to change instantly to the white board and start writing.  I briefly explained the  LTSP  with a figure that I drew and later on moved the projector to my laptop. The presentation was shown after explaining things with a white board.  I think half of the audience got confused by then.
The next session from UST global was  quite boring. I think such PR crap should be avoided in barcamps. I missed the session by Binny VA as I went out for a tea again.

The last session on linux devices was good,  but Praseed Pai  seemed to be the only person understanding it.
Finally, Fr. Abraham Mulamootil made a surprise appearance. I think it is the first time a catholic priest is seen publicly in a bar(camp). Any way he seems to be the only geek in the church.
The entire event was wound up around 6pm.
The facilities at the venue were pathetic.  No one from the college turned up. There was no net connectivity.  The wifi link of the college was running but their firewall was preventing outgoing net  request. Hope the next barcamp at Thiruvalla will be better and more interesting.

vu2swx Computers, Gnu/Linux

As I travel frequently  in connection with my official and no-official engagement, my internet presence is disrupted. I have tons on mails and rss feed entries to be read after each journey. I was thinking of buying a netbook.
I recently bought a Toshiba NB200 netbook at a discount rate from my cousin. It came with 160 GB hard disk 1GB RAM, intel atom processor and Windows XP was pre-installed.
The first thing I did with the netbook was to remove windows. I installed ubuntu netbook remix 9.10, All the hardware except sound was instanly recognised by ubuntu. My next task was to  make it internet ready. I looked for various solutions like evdo from BSNL , netconnect from reliance etc. They all looked costly.
Finally I decided to go in for GPRS connection from BSNL. I  am already an unlucky owner of Nokia N72 , which is recognised only from windows. Fortunately the GPRS modem on N72 is accessible from linux . Here is what I did with my BSNL prepaid  phone connection to get it ready for my net book.

1) Enable GPRS on the phone

The GPRS can be enabled on BSNL connections by sending an SMS to  53733 with the following  word.  GPRSPRE. (I use a prepaid connection). They charge heavily    for GPRS usage 10 paise per KB.  However, they have some schemes which provide unlimited Internet access.
If you are a sporadic traveller, unlimited gprs access  for one day can be availed at Rs.20. For ardent travellers, an unlimited connection for one month can be subscribed at Rs 230. For availing the special schemes, you have to send sms to 53733 with the word GPRS20 (or GPRS230). You need a minimum balance of Rs 75 in your prepaid account for availing GPRS20. Once you send the sms,BSNL will ask you to confirm the scheme by sending another sms with GPRS20Y to 53733. (Sometimes it takes an hour or so  to get back the sms asking for confirmation. Being an Indian, you have to be patient.)

2) Configuring the Modem.

This was rather easy as my N72 GPRS modem was recognised as soon as I plugged the data cable.
I verified its presence  by looking at dmesg output on a terminal.

I installed wvdial from the ubuntu repository .

$ sudo apt-get install wvdial

Next, I ran the following command.

$ sudo wvdialconf

It created a minimal configuration file for wvdial  /etc/wvdial.conf.

/etc/wvdial.conf was then edited as shown below.

[Dialer Defaults]
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Init3 = AT+CGDCONT=1,”IP”,”GPRSSOUTH.CELLONE.IN”,”",0,0
Modem Type = USB Modem
Modem = /dev/ttyACM0
Baud = 115200
Dial Command = ATD
Phone = *99***1#
Username =9194461xxxxx
Password =9194461xxxxx
New PPPD = yes
Stupid Mode =yes

Use your phone number as username and password. I entered the phone number including the country code as shown above. Also look at the Init3 entry. If you are in south India, you can use the above line. For other regions look at this page.

Now you can access internet by dialling out using wvdial.

$ sudo wvdial

The internet speed is reasonable.

I am posting this from Venad Express on my way back from Model Engineering college where I delivered a lecture  on free software. The netbook was really handy for the presentation too.

vu2swx Computers, Uncategorized

I  was away  from home for a week and returned back yesterday evening.  As I had a weeks emails pending, the first thing I did after reaching home was to  access gmail. To my horror,  google was telling me that I am providing a wrong password. Then, I tried to log in to my blog. I found out that my blog has been defaced. I was getting the following screens, Some Arabic bymn was played in the background.

This page will give you some more information on how a hacked page look like.    I contacted my web hosting provider  and got the password for the site reset and the site was  back with in my control.

However  gmail id  was my lifeline and I had to recover it at any cost. I tried to  recover my password from the gmail login page as below.

The next page had these options.

I selected my account has  been compromised  which gave me the following link.

The account recovery page is here. Have a look at it.  Your scucess in retrieving the  account lies in accurate answers in this page. I filled out the following sections.

Fortunately, I remembered who invited me to gmail.( I  had a gmail account at a time when gmail invites were sold on ebay).   Also, I use filters and labels heavily for handling mail.   There was some fuzziness with dates , still I could approximate it.   I have a couple of blogs linked to the account and an orkut profile. I knew only the url of my blog on blogspot.  I  was very skeptical whether I will get it back. I submitted and waited  any response form google.  About an hour later I recievd the following mail from google.

I reset the password and  retrived my account.  The attaker had tried to capture some of my other  on line assets from the gmail id. Some of  the automated responses had his IP address logged( or it might be a proxy). I traced the attacking  IP  to Saudi Arabia.

Why I lost my account ?

There  may be several reasons. Here are some of my assumptions .

a) I had a weak password. ( 6 letters and that too based on a dictionary word)

b) I had enabled POP3 access for my gmail account, even though I was not using it. There are plenty of scripts like this available on the Internet  for  brute force  attack on gmail accounts via POP3.

c) I had used my account from a friends place last week  on a windows XP machine. May be that machine has a key logger installed and the attacker might have obtained the password via IRC  from there.  I cheeked my home machines  for  any possible root kits,  but I could not find any.   My windows machines do not have internet access.

d) Some one might have stolen the password from one of the machines that I use at college. ( As we are having vacation now , I  can safely rule out this possibility)

What  information one must keep about  google accounts.

1) If some one invited to a gmail account ,  keep the email.  It can save you a lot of trouble.  It will give you some idea about the date of creation  of your account.

2)  If you use labeling and filters , remember the labels.  You can give easy to remember names  and  context relevant labels to your mail.

3)  Even if you are not blogging , create a blog on blogspot . The URL of the blog can be an important information.

4)  Email addresses are not by hearted as phone numbers.  So export the your gmail contact list to a file and keep it. The account recovery page asks for   up to five frequently contacted email ids. ( Click on contacts on the left side of any gmail page and select export to save the contacts.)

5) Set up a secondary email id  and give it a different password.  ( You can use Settings->Accounts->google account settings-change security question for this.)

6) Set up a  security question.  It can save you a lot of trouble.

7) If you use orkut, keep the URL of your orkut profile.

You can obtain it from your orkut home page as shown in the figure below.

9) Disable POP3 and IMAP if you are not using them.

10 Use a Strong password. This is the most important step.  In the change password page, make sure that your password is strong as shown in the picture  below.

vu2swx Computers, Electronics bader2010

Installing LTSP and enabling thin clients to boot from your ubuntu 9.04 machine is very  easy.

I did the following steps.

a) Install ubuntu 9.04   ( aka Jaunty) desktop   with a static IP.    (  A static IP is needed as your ubuntu box is going to act as a server. My IP is 192.168.0.1). Set up Internet access on this machine. You need to download a lot of packages  from the net to complete the installation.

b)  Install  the packages  ltsp-server-standalone and openssh-server

# apt-get install ltsp-server-standalone
# apt-get install openssh-server

c)  Build the LTSP client environment.

#ltsp-build-client

This  command will download all the necessary packages from Internet and build  your environment.

Have a look at /opt/ltsp/i386. This directory will  now contain the chroot environment for the thin clients.  If you want to tweak any settings  you cna do it here.

d) Edit the  /etc/ltsp/dhcpd.conf to suit your network setting. This file  will serve  the ip range  192.168.0.20 192.168.0.250 by default. If your network uses this range you can leave it  as it is. (The default file worked for me as my server IP is 192.168.0.1)

e) Run the following commands.

#ltsp-update-sshkeys

#ltsp-update-image

The first  command above will export the ssh keys of the server  to the ltsp client environment. The  ltsp-update-image command will rebuild a squashfs image from the ltsp chroot environment and place it under /opt/ltsp/images directory.  This image will be exported to the thin client as root file system by the NBD daemon on the server.

Your LTSP server is ready.  Try booting form a client via pxe or etherboot. You can also try to boot the thin client in qemulator.
There is a sample script for this in /usr/share/doc/ltsp-server/examples/ named qemu-ltsp.

Note:    If you change any thing under /opt/ltsp/i386 , you must rebuild the image for the change to be reflected on the client. Also, if you change the IP address of the server you must do an ltsp-update-sshkeys followed by  ltsp-update-image.

vu2swx Computers, Gnu/Linux, Living in India, Uncategorized jaunty, ltsp, ubuntu

Today  I was  playing with ubuntu 9.04 .  I tried to install  wwwoffle the  off-line  proxy server.  At the end of installation it failed with a  ” Sub process /usr/bin/dpkg failed ” message.  There was some thing wrong.    Fixing the system required removal of the package. I tried the following in succession in vain.

# apt-get remove wwwoffle

#dpkg -P wwwoffle

#dpkg –force-all  -r wwwoffle

I was stuck.  I did a manual removal of the deb package like this.

a) List out all the file of the deb package.

# dpkg -L wwwoffle

b) Removed all the files from the above list by hand.  If you are smart enough you can write a script for that.

c) Remove the package using apt

#apt-get remove wwwoffle

vu2swx Computers, Gnu/Linux jaunty, ubuntu