Ashwin's Blog

Logging TCP state variables such as Congestion Window from user space

2012-02-14T19:41:00.000+05:30

If you are familiar with hijacking library calls using LD_PRELOAD then this should be very intuitive. The following code should help you monitor some of the tcp state variables. I am using the following code to log the evolution of the TCP congestion window during an scp session. Please have a look at tcp_info structure available at /usr/include/linux/tcp.h and the tcp_info structure in the kernel tree. I needed only the variable related to the congestion window and timers for my work. You can modify the periodic_alarm function to suit your need. This code works for scp, for other applications you might need to modify the socket descriptor used in the periodic alarm file. Happy Hacking!

 
#define _GNU_SOURCE  
#include <sys/syscall.h>  
#include <sys/types.h>  
#include <sys/socket.h>  
#include <stdio.h>  
#include <stdint.h>  
#include <dlfcn.h>  
#include <signal.h>  
#include <netinet/tcp.h>  
#include <sys/syscall.h>  

/*
 * THIS WORKS FOR SCP WHERE ONLY ONE CONNECTION IS USED
 */ 

int (*real_socket)(int domain, int type, int protocol) = NULL; 
int sockfd = 0;
struct sigaction sact;
long long start_time;

/*
 * Periodically dump the info from the socket.
 * Note this assumes that the tcp_info struct includes tcpi_total_retrans. 
 * Older versions do not support tcpi_total_retrans
 */
   
void periodic_alarm( int sig )
{
  
  struct tcp_info info;
  int infoLen = sizeof(info);
  struct timeval now;
  long long curr_time;
  
  gettimeofday(&now, NULL);
  curr_time = (now.tv_sec*1000)+(now.tv_usec/1000);  

  getsockopt(sockfd, SOL_TCP, TCP_INFO, (void *)&info, (socklen_t *)&infoLen);
  
  fprintf(stderr,"%llu %llu %u %u %u %u %u %u %u %u %u %u\n", curr_time,
   curr_time - start_time, info.tcpi_snd_cwnd, info.tcpi_snd_ssthresh,
   info.tcpi_unacked, info.tcpi_lost, info.tcpi_retrans, info.tcpi_total_retrans,
   info.tcpi_rtt, info.tcpi_rttvar, info.tcpi_rcv_rtt, info.tcpi_rto);  
}

int socket(int domain, int type, int protocol)
{
  int fd;
  struct timeval now;
  
  if (NULL == real_socket)
    {
      real_socket = dlsym(RTLD_NEXT, "socket");
    }
  fd = real_socket(domain, type, protocol);  
  /*
   * For scp the first socket is enough
   */
  if (SOCK_STREAM == type&SOCK_STREAM && 0 == sockfd)
    {
      gettimeofday(&now, NULL);
      start_time = (now.tv_sec*1000)+(now.tv_usec/1000); 
      // if (sact.sa_handler != periodic_alarm)
      sigemptyset(&sact.sa_mask);
      sact.sa_flags = 0;
      sact.sa_handler = periodic_alarm;
      sigaction(SIGALRM, &sact, NULL);
      ualarm(999000,10000);// Wait for 1 second then every 10 ms      
      sockfd = fd;
    }  
  return fd;
}

/*
Compile with the following command
gcc -shared -ldl -fPIC wrap_socket.c -o wrap_socket.so
Run scp as follows 
LD_PRELOAD=./wrap_socket.so scp fname username@machine:path 2>logs-1
*/

Some thoughts on the culture of arbitrariness

2011-09-30T17:47:00.034+05:30

Today during lunch, one of advisors asked me "How is it that India still remains to be poor?" I was full of answers, however to keep it short I said "it's complicated." However, one answer which is becoming more and more important is favoritism, nepotism, or as we call it in India "Do you know who my father is?" Well if you have a very powerful father the laws in India can be completely bent to ensure that you and your father still remain the king! P. Sainath calls it the culture of arbitrariness. Arbitrariness which includes waivers being given citing emotions and sentiments of the mass public, waivers that make absolutely no sense at all.

Lets have a look at one such waiver and let me begin by some simple questions. Now, do want the person who breaks the law to be punished or not? What if the person is really influential? Do you want him to pay the penalty for breaking the law? Now if I say that the person who is to pay the penalty is a politician then I guess all the members of "I am Anna Hazare" fan club would proudly say Yes!

Before looking at who the guilty is, lets evaluate the impact of the misdeed. For starters, lets account for the impact of a small loss say Rs 500,000. Say Rs 500,000 should have been collected by the government as taxes or a penalty or a fine. According to the pain staking research done by the intellectuals of the Government of India, Rs 32 is enough for a family for one day for all its daily expenses. On Rs 500,000 this family could have merrily lived for a little over 15,000 days which in years would be close to 40 years. Considering the life expectancy of poor people, this would be enough for one lifetime of one family. So, according to our wonderful Indian Government, one family could have survived for one lifetime if the government would have taken the Rs 500,000 which it should have. Another way of looking at Rs 500,000 is that with this amount the death of 15,000 Indian families (or 60,000 Indians considering a family size of 4) could have been delayed by one more day!

Now lets change the situation a little bit. Say if a really rich person is exempted from paying a tax which he/she should have paid? Wouldn't there have been a hue and cry? Now consider the amount of Rs 1.13 crores in taxes, i.e., Rs 11300000 (yes there are 5 zeros here!). This amount at Rs 32 a day, would have delayed the death of 353,125 Indian families or 1,412,500 million Indians by one more day. Another way to look at it is it would have been sufficient for 21 families for close to 45 years! Now if I say a politician, say for example Sharad Pawar got a tax waiver of this amount of Rs 1.13 crores for one of his agri-business then the whole country would have made a huge hue and cry. There would have been a trial by media and possibly some of his effigies might have been burnt by some patriotic soul.

I completely agree that there should be a huge hue and cry for this. But that is where the culture of arbitrariness kicks in. Wouldn't a politician suffered a trial by media if he seeked a waiver of taxes or penalty. My question is, now just because Sachin Tendulkar is in the guilty box, why isn't there a huge hue and cry? Why is it that Sachin Tendulkar is finding it difficult to pay a fine which he rightly should according to the law? I find it really amusing and disturbing that the very state government which could do nothing for their farmers who committed suicide, the very state government that has turned a blind eye to the hunger related deaths in Thane district (less than 200 km from their offices in Mantralaya), has gone out of the way to seek a waiver of Rs 475,000 for Sachin. Also I find it difficult to think that the central government waiving the Rs 1.13 crore in duty for the Ferrari of Sachin. Now this amount is a drop in the ocean considering that the IPL is exempted from most of the taxes and so is the BCCI. What worries me is the that the RTO officer who was responsible for this waiver of Rs 1.13 crore on Sachins Ferrari went on to create the now defunct Kochi IPL team.

It is this sad culture of arbitrariness which is becoming the root cause of some the worst problems plaguing India. Tax waivers being given to corporations, mining contracts being given to relatives of politicians, houses to be allocated for war heroes being diverted to political families. This issue of Rs 500,000 might seem small but on a larger scale just think about it. Imagine a tribal family living in a village with no electricity. How can you tell that family that the government is sorry that it cannot provide any medical aid to a sick child because it has no funds. How has the infant that is loosing its life while you are reading this article benefited from one of the beautiful batting innings of India's batting maestro -- isn't the infant paying the price of the sick waivers being given by the government!

Sources:
1. http://www.rediff.com/cricket/2003/aug/09sach.htm
2. http://www.rediff.com/cricket/report/maharashtra-govt-asks-bmc-to-waive-penalty-on-tendulkar-house/20110929.htm
3. http://articles.economictimes.indiatimes.com/2010-04-16/news/28419652_1_tax-waiver-shailendra-gaikwad-bike-scam

Saving your passwords file using gpg

2011-09-20T18:15:00.010+05:30

gpg provides a nice tool for encrypting and signing files. I am currently using gpg version 1.4.11 to save my passwords.It is available for most linux distros and is very easy to use.

For example if I have a plain text file with the names and passwords I used in various banks


--
bank: velma inc
login: scoobydoo
account: 112358
password: scoobysnacks

bank: haddock gmbh
login: snowy
account: 31415
password: tintin
--

I have this filed saved as finance-passwords. Then with gpg I encrypt it using the following command:

 > gpg  -c --force-mdc finance-password

This creates a file finance-password.gpg in the same folder. Note the --force-mdc which needs to be provided. --force-mdc is to use encryption with a modification detection code while -c is to encrypt with a symmetric cipher using a passphrase. Do a man gpg for further security stuff but for guys like me this is enough.

The encrypted file can be decrypted using the following command

 > gpg finance-password.gpg

This creates the file finance-password. During decryption I get the warning

gpg: WARNING: message was not integrity protected

if the --force-mdc option is not used during encryption.

First conquer the evil in you

2011-08-17T20:09:00.030+05:30

In the last few days, thanks to the zillions of news channels and news papers in India which have their content online, I have seen Indians getting emotionally charged like never before in the last couple of decades. Here is a list of questions I would like to ask each emotionally charged Indian. I pray that after reading these questions you are still charged up to address the issue of corruption that is raping my country and this beautiful earth.

1. Have you voted in the last general, assembly, and municipal election?
You can protest if you have taken part in the democratic process. If you have not performed your duties the question of your rights does not arise. Only those who have performed their duties should talk about rights.

2. Have you updated your ration card? Are you buying food from the allotted Ration shop? If no have you converted your card to a card that indicates you will not buy food from (public distribution system) PDS shops? (In Pune my family has a white ration card which is for people who want the card only for address proof and not for rations).
The questions ask you if are indirectly contributing to malpractices due to your ignorance (which is unpardonable given that you can at least read english) and lethargy. The above questions are related to hunger in the country which is by far the biggest proof of inequality, and the dirtiest consequence of any malpractice -- killing a person with hunger makes the killer a parasite which feeds on another living creature. The government uses PDS to ensure that the population gets the bare minimum supply of food. Sadly malpractices in PDS result in hunger related deaths. These malpractices coupled with inflation is making rotational hunger common in many areas. Rotational hunger is when a person eats one day so that he/she can work in the fields or the MNREGA; the next day another family member eats and goes to work -- the money that finally reaches the household after a days worth of manual labor (close to 12-15 hours) is enough to feed one person and if possible his/her children thanks to inflation. Your laziness and ignorance gives officials working in the PDS a chance to be manipulate the food supplies; this indirectly also affects inflation.

3. Have you filed your tax returns? Have you submitted false information to reduce your income taxe and/or other taxes? For example given false rent receipts to reduce your income tax.
People reading this blog post have access to the Internet; hence most probably have sufficient earnings to be taxed. Black money is the money that should have been taxed. This question asks if you have created some black money.

4. Have you bought a house? How much cash did you pay your builder to reduce the property tax?
Corruption and black money is not limited to the government sector. The private sector is a big source of black money. Once black money is created it begins to flow as bribes.

5. Have you paid a bribe because you thought paying money is preferable? For example paying Rs 100 is better than Rs 500 for a traffic rule violation or it is better to bribe rather than waste time waiting in a queue.
Giving a bribe is morally (if not legally) a crime of the same magnitude as that of taking a bribe. एक हाथ से ताली नहीं बजती -- it takes two to tango.

Anna Hazare is fasting against corruption. One of the objectives of a fast, according to Mahatma Gandhi, is self purification. Going on a fast does not mean that your sins are pardoned after the fast; a fast is supposed to awaken the very conscience that you have inherited thanks to the billions of years of the evolutionary process. This awakening shall guide you and help you guide the ones around you from committing the mistakes previously committed. Anna's fast and protest is against the evil of corruption. He can fight this battle because he has not let the evil conquer him. To become part of his battle you must first conquer the evil in you before you start your attack on the evil present around you.

Before you begin any battle please keep in mind this quote by Friedrich Nietzsche "Be careful when you fight the monsters, lest you become one."

Notes for the Evolution 101 course

2011-06-22T16:19:00.029+05:30

A few notes from the Evolution 101 course from UC Berkeley [1]. I am guilty of rampant plagiarism however, I had to do so because the words used in the Evolution 101 course are precise and unambiguous.

Evolution means that we're all distant cousins: humans and oak trees, hummingbirds and whales.
Scientists constantly reevaluate hypotheses and compare them to new evidence. As scientists gather even more data, they may revise these particular hypotheses, rearranging some of the branches on the tree. For example, evidence discovered in the last 50 years suggests that birds are dinosaurs, which required adjustment to several "vertebrate twigs."
We can reconstruct evolutionary relationships and represent them on a "family tree," called a phylogeny.
Because a phylogenetic tree is a hypothesis about evolutionary relationships, we want to use characters that are reliable indicators of common ancestry to build that tree. For example, birds and bats both have wings, while mice and crocodiles do not. Does that mean that birds and bats are more closely related to one another than to mice and crocodiles? No. When we examine bird wings and bat wings closely, we see that there are some major differences.
If you wanted to squeeze the 3.5 billion years of the history of life on Earth into a single minute, you would have to wait about 50 seconds for multi-cellular life to evolve, another four seconds for vertebrates to invade the land, and another four seconds for flowers to evolve — and only in the last 0.002 seconds would "modern" humans arise. Life began 3.8 billion years ago, and insects diversified 290 million years ago, but the human and chimpanzee lineages diverged only five million years ago.
Evolution is the process by which modern organisms have descended from ancient ancestors. Evolution only occurs when there is a change in gene frequency within a population over time
Humans did not evolve from chimpanzees. Humans and chimpanzees are evolutionary cousins and share a recent common ancestor that was neither chimpanzee nor human. Humans are not "higher" or "more evolved" than other living lineages. Since our lineages split, humans and chimpanzees have each evolved traits unique to their own lineages.
Mutation, Migration, Genetic drift, and Natural selection are the four processes that are the basic mechanism of evolutionary change
Biologists use the word fitness to describe how good a particular genotype is at leaving offspring in the next generation relative to how good other genotypes are at it. So if brown beetles consistently leave more offspring than green beetles because of their color, you'd say that the brown beetles had a higher fitness.
Natural selection is the simple result of variation, differential reproduction, and heredity — it is mindless and mechanistic. It has no goals; it's not striving to produce "progress" or a balanced ecosystem.
A species is often defined as a group of individuals that actually or potentially interbreed in nature. In this sense, a species is the biggest gene pool possible under natural conditions.
All available evidence supports the central conclusions of evolutionary theory, that life on Earth has evolved and that species share common ancestors. Biologists are not arguing about these conclusions. But they are trying to figure out how evolution happens, and that's not an easy job. It involves collecting data, proposing hypotheses, creating models, and evaluating other scientists' work.

Now for a list of misconceptions [2]:

Evolution is just a theory.
Evolution is like a climb up a ladder of progress; organisms are always getting better.
Evolution means that life changed by chance.
Natural selection gives organisms what they need.
Gaps in the fossil record disprove evolution.
Teachers should teach both sides (read evolution and creationism) and let students decide for themselves.

The reason for this blog posts are as follows

I am hearing "Evolution is just a theory" a lot these days.
To end some debates I used to say "Teachers should teach both sides". I should stop saying this [2].
I say used to say Humans evolved from Chimpanzees. This is also wrong [1].
I used to wonder if random mutation and natural selection has a long term goal that ensures resources are sustained. Apparently there is no long term goal, as the course says that natural selection is mindless and mechanistic. This is important as evolution neither guarantees nor does it work towards sustaining the available resources.

[1] http://evolution.berkeley.edu/evolibrary/article/evo_01
[2] http://evolution.berkeley.edu/evolibrary/misconceptions_faq.php

Learning to Sort

2011-04-09T13:34:00.011+05:30

Here is a collection of videos I found in the Internet for sorting algorithms. (Thanks to Antonio and Prem Piyush for their facebook posts).

1. Bubble Sort:

2. Insert Sort:

3. Select Sort:

4. Shell Sort:

And my favorite is to see how the various sorting algorithms sound like. This one is really nice as you get a feel of why time complexity matters a lot!

My favorite however is Heap Sort.

PhD and The Hair Cut

2011-03-02T21:07:00.007+05:30

Occasion: This week I shall be finishing 1 1/2 years of PhD. My rate of going for a hair cut has reduced so much that I fear that by the end of my PhD I might not need a hair-cut.

Matlab Code (sans Annotation):
x=0:0.01:3;
y=0:15*pi/300:15*pi;
plot(x, exp(-x)+0.05*sin(y), 'linewidth', 3);
set(gca, 'xlim', [0,3]);
set(gca, 'FontSize', 20);
ylabel('Need for Haircut', 'FontSize', 30);
xlabel('Time spent as PhD student (years)', 'FontSize', 30);

Trip with Friends

2011-02-01T23:48:00.008+05:30

My photographic skills as a sine wave from 0 to 4π.

Honest and Stable Government: Is existence of India as a country a random miracle?

2011-01-24T21:26:00.035+05:30

In the last few weeks I read two interesting status messages on facebook.

You can bring the horse to the well, but you cannot force it to drink. But if you bring it 2, 3 times to the well and he still doesn't want to drink, then it is probably a donkey.
Une phrase qui tourne en ce moment..."un président qui s'enfuit, un premier ministre qui pleure à la télé, un blogueur qui sort de prison pour devenir secrétaire d'État, un juge exclu d'un plateau de télé, une manif de flic, un avocat qui fait la circulation, des patron qui se font licenciés par les employeurs...est ce qu'il y a un gros nuage de fumée de cannabis qui passe au dessus du pays???? (Last sentence asks if there is a dense cloud of cannabis passing over my country).

The first is in the context of Belgium and the second in the context of Tunisia. Both countries are currently in desperate need for a stable and honest government. In contrast, the Indian government is toiling hard to show that these two words, stable and honest, are logical complements of each other and do not complement each other. In India there exists a government, at least on paper; but it is doing everything apart from governing and is busy enacting the meaning of the word "sucks". It is using stability as an excuse for being completely dishonest and showing the world what it is to be absolutely corrupt and suck the nation dry. One thing that I like about this government is that it has shown that independence is an on going process and it is wrong to say India gained Independence in 1947. It always amazed me how a handful of Britishers (less than 100,000) colonize a country. In fact they could because there were agents like the ones we now have outside every government office; agents who are willing to sell everything. And when I mean everything, I mean each and everything that is on this Earth -- from humans as slaves (human trafficking of girls from the north-east for forceful polyandry to counter skewed sex ratios -- modern day draupadis in Punjab), to the land (we even have our military having dirtying their hands in Adarsh and the Sukhna land scam), and natural resources (how can we forget the iron-fisted Reddy brothers and coal mafia operating with the blessing of Soren). To be frank, I thank this government for showing everyone in the world that from a Birth certificate to the Death Certificate one might have to pay a bribe in India.

Satish Acharya's Cartoons

Further, this corruption is not limited to the public sector. With the Radia tapes Indians have shown the world that US style lobbying fortified with the powers and thinking of an Indian dalaal (agent) can be used by the private sector to sell to the country. With Manmohan Singh at the helm, there was a glimmer of hope. However with time it has become clear that this glimmer is basically the light being used by the UPA to misguide the Indians on the road to hell.

Well this road to hell was evident with the appointment of Bureaucrats. To begin, take MS Gill, the current sports minister who was in the past the Chief Election Commisioner. Now the very MS Gill is the member of the Congress. How can one believe that all his decisions taken as the CEC was not to please a a particular party. The same is true for Navin Chawla. Speaking of bureaucrats, this government has taken the country to new lows by the appointment of the Chief Vigilance Commissioner; the one responsible for blowing the lid of the scams. Can Manmohan Singh explain the motives behind his insistence on having a scam tainted bureaucrat to head the Central Vigilance Commission. To make matters worse, how can one expect a bureaucrat to investigate the $38 billion telecom scam that took place when he was the top ranked bureaucrat in the telecom ministry. Also given this mentality how can one expect this government to bring the $1.4 trillion dollars of unaccounted money back to India; money whose source includes hawala, drugs, arms trading, human trafficking, and I guess the deeds which even God doesn't know and might be ashamed to see.

At times it is hard to comprehend what India gained from Independence. Yes we have freedom of speech -- however this is abused big time by the Geelani family, Arundhati Roy, and recently Digvijay Singh to speak complete nonsense. We were supposed to have equality but we have a potential prime-minister, Rahul Gandhi, who visits a house because it is a Dalit's house and not because it is a house of a fellow human being let alone an Indian. To be frank the ruling class and the babus have shown that there exists no discipline in India and at the same time indiscipline is being used as a metric to show the power. Basically in the last 60 years we have overthrown the true leaders who fought for Independence and replaced them with the very bullies who sold the country to the Britishers; this time however they are selling it to themselves.

The only positive side is that India continues to give birth to the ones like Homi Bhabha, Abdul Kalam, and millions of selfless and true Karma-Yogis, whose names will never appear in any history book; these nameless individuals are responsible for the existence of this country as they are miraculously unaffected by the cloud of the cannabis smoked by the ruling class. I only hope that the existence of my country is not some random miracle.

Friends on Facebook

2011-01-09T21:47:00.011+05:30

Friends on Facebook

The R code used to generate the above plot. [This is my first plot using R.]
---
x=seq(0,5,0.01)
y=exp(-x)
#pdf("~/tmp/foo-R.pdf")
jpeg("~/tmp/foo-R.jpeg")
plot(x, y, xlab='Time spent on facebook (hours/day)', ylab='Fraction of "friends" you actually socialize with', type='line', lwd=3, cex.lab=1.5, cex.axis=1.5, xaxs='i', yaxs='i')
grid(10,10)
dev.off()
---

De-Pressing Press

2010-11-22T22:00:00.059+05:30

Once upon a time, not so long ago, folding a newspaper earned me a praise from my parents. It was during this golden era of color TVs when I first came across divine souls called newscasters. Baldevanda Sagara, with his famous starting line संस्कृत वार्ता .. प्रवाचीतः बलदेवानंद सागरः, Pradip Bhide of the evening news in Marathi, and the English news presenters of Doordarshan were my demi-gods. As I grew older, I witnessed an exponential growth in number of news channels. It was during this time that I actually experienced an even faster decline in the quality of news. I have seen the Times of India evolve into a soft porn magazine which sells sex in the name of art and erotica. Pune Times (previously known as Pune Plus) evolved to having two kinds of articles: how much did one have to expose just before sleeping with Mr/Mrs. X; and whose make up can scare you more than all the Ramsay movies put together.

Things were a bit different during the Kargil war though. It was during this war that I witnessed some really courageous reporting. I can still remember Barkha Dutt interviewing soldiers and seeing the courageous fuel tank drivers piercing the fire from other side. One of the interviews I cannot forget was that of the great Capt. Vikram Batra. Sadly over the years my respect for this reporter and her so called journalism has gone so low that I do not want to write her name in a sentence having the name of Vikram Batra. This decline in respect began a few years ago when I saw some of her debates. During each debate I was getting a feeling of some preconceived idea being forward. There were times when someone making a valid point was stopped by really stupid excuses such as, "I believe Mr. X has something to add to this; lets go to Mr. X". The level went really low during some of the interviews I saw of the CommonWealth Games. These have been criticized in my previous blog posts "Where are the reporters?" and "The Great Indian Tamasha: Common Wealth Games." Here are the two videos that really highlight the lack of any spine in her interviews.

Sadly she is not alone and is part of the mother of all reality shows called News channels. The flashing news in these channels literally flashes. Lighting flashes are less painful to the eye as the colors used by these channels compete with the creativity of Ekta Kapoor. One question to all news channel - Why are you bombarding us with inconsistent text and video? If there was some consistency then the brain would not have any problems getting the message. However, most of the text you show is completely out of context and many a times makes no sense at all. Due to this inconsistency I can either read or listen but never comprehend what you want to say. There was a time when news clips came without background scores. These news clips were neat and simple presentation of facts or events. Lately, rather than the voice of the presenter, I hear background scores trying the vibrate the very emotion chords that have been incapacitated by the works of Ekta Kapoor & Co. Such cheap tricks were once used by the Times of India when it started highlighting some words of a news article. Did the editors of the Times forget the purpose of something called a headline? Was the editing time so less that the editor just highlighted the words he/she read before publishing the crap.

For me the press died the day newspapers evolved from a समाचारपत्र or journal to a PR newsletter; the press died when it became a medium to brainwash the masses and stopped being a medium to inform events and facts; the press died when ratings took precedence over the very conscience that separates us from parasites. Just like we want Kalmadi to resign, it is high time that people like Barkha Dutt, Vir Sanghvi, and their partners quit. The impact of paid news is worse than every scandal that rocks the country as paid news can control and manipulate how people can perceive the scandal. There is an age old saying that being स्तिथ प्रज्ञ is a necessary condition for understanding the truth. I can only say that the press in its current form does not satisfy this condition.

An Obama Diwali

2010-11-16T22:30:00.030+05:30

Diwali is the time of the year when shopkeepers make the most of the temptation to spend. Well the biggest shopkeeper just visited India and returned as a demi-god thanks to the "Athithi Devo Bhava" philosophy. Indians expected this visitor to be a Nobel Atithi - he however turned out to be a very shrewd businessman in a Nobel Athithi's clothing.

Barak Obama came, saw, and conquered (just fell short of plundering). He just showed what a bunch of spineless leaders we really have. It is pretty clear that his visit was not mutually satisfying. America's gain dwarfs even the illusion of gain which India was shown. He left with jobs for America and yes mesmerized the press with perfect diplomatic sentences such as, "That is why I can say today — in the years ahead, I look forward to a reformed UN Security Council that includes India as a permanent member." One question to Mr. Obama - just how many years did you say? On Headley, USA just showed that India has the duty of being resilient but not the right to have a concern let alone voice the concern. I just wonder what would have been the reaction of the US if India hid the information of a double agent who was plotting against the US.

India is not a friend of the US; it is just a market or should I say dumping ground. Have we forgotten the Congress grass that plagues almost every district of the country. Why is India pushing for untested and potential dangerous agri-tech from the US (Article by TJS George on this issue)? Why are they not safe for use in the US but safe for India? If we are really a developed nation, then why these double standards? For the last two decades China is a manufacturing hub for America, and India's vast population its market. If Obama was really concerned of Indo-US business trade, he would not have skipped Bangalore or have a phobia of being Bangalored. He did not come to improve trade, he just came to sell stuff. His magical spell worked so well that the Indian press completely forgot that India has (at least on paper) a President and it is not Barak Obama.

One thing that hurt me (personally) the most was his statement, "Strong, peaceful Pakistan is in India's interest." Can he make such statements in China about the dams they are building or the troop movements they are capable of? Then why should India care what he says? To be frank, for the last 60 years Indians would have been much more happier if they had a strong and stable Pakistan, rather than a one being run by the sympathizers of Taliban. One can draw a simple analogy from cricket. Indian cricketers would love to face the bowling a person like Wasim Akram who truly loves Pakistan than the playing with guys like Sohail Tanvir who make public statements full of hate such as "Hinduon ki zahaniyat hi aisi hai". Any sane International Cricket team would prefer to face the Pakistan that won the world cup rather than a team full of match fixers and their sympathizers. Similarly, India would have loved to have a stable Pakistan as its neighbor rather than one run by the Taliban and its sympathizers. Saldy, India and Pakistan has to suffer the legacy of Zia-ul-Haq and the mess US created while fighting a proxy war against the ailing Soviets. Another question:

To conclude, Obama is a capable of doing great things. However he received far more attention than he deserved, and India got far less compared to what it truly deserves. I only hope and pray for a better leader to lead India who knows who is an Athithi and who is a shopkeeper...

Buddhi and the Coalition Dharma

2010-11-12T18:20:00.049+05:30

बुद्धि (Buddhi) and धर्मा (Dharma) are two Sanskrit words that do not have an equivalent in English or any Latin based language. Their meaning is supposed to be imbibed in the very essence that makes us Indians. When our Buddhi tells us that something is not right, it is our Dharma to take appropriate action. Each Dharma comes with actions to be performed and right now we are witnessing the actions of a new Dharma. It goes by the name Coalition Dharma. So what exactly is Coalition Dharma. Here is what I have seen in the last few years...

Let us first have a look at the party which projects itself as the one that has the copyright on the Bhagvad Geeta. Does anyone remember a person called Shibu Soren. Four years ago, the BJP was trying its best to skin this guy alive. A couple of years later they decide to dress him with an armor called Chief Minister. Then one fine day they decide to strip him naked and don the armor themselves. I guess life of Schrodingers Cat is more predictable than the future of Jharkhand.
Does any one remember the circumstances when a party called the Nationalist Congress Party was created? On May 20, 1999, Sharad Pawar and three of his friends were expelled for revolting against Sonia Gandhi. According to its website, the NCP claims to be "a true inheritor of the rich and glorious political legacy handed to the Indian National Congress (INC) by early stalwarts like ...(infinite list of every person whose name can be found in 3rd standard history textbook)". Sadly in their zeal for nationalism they forgot the name of the congress founder Alan Hume. Well I am not sure if any Nationalism still exists in this party, as they are busy plundering Maharashtra for close to a decade now with the Congress Party.
My knowledge of Communism is limited however even a little Buddhi can tell that one Communist pointing guns at the other seems to be wrong. Further, they claim to be secular and yet have an on and off relationship with the Indian Union Muslim League. How according to any communist ideology a political party that has the name of a religion be secular?
Satish Acharya
About the Congress. They are the ones who taught India its current version of Coalition Dharma. They started by giving us Deve Gowda as the PM. Now as their power has increased their Dharma has evolved to new heights. To become part of their Dharma one has to worship their three demi-gods: Jawaharlal Nehru, Indira Gandhi, and Rajiv Gandhi. A footnote read while being introduced to their Dharma is the that one has secretly worship Sonia. Once this is done you become part of their Dharma which is part of the grand Coalition Dharma.

Satish Acharya

One of the best cartoons talking about the insanity called Coalition Dharma is the above cartoon by Satish Acharya. Such promiscuous behavior just shows the lack of any Buddhi in the Coalition Dharma. It just highlights the true essence of this Dharma which has its root in corruption. A good proof of the corruption being the only motivating factor in politics is the following video.

This video from Pakistan sheds light on the mentality of all the politicians in the sub-continent. The politician being questioned says "We have a right on being corrupt. A party can be less corrupt only if it is not in power." This is true and is inline with an age old saying, "power corrupts; and absolute power corrupts absolutely". Coalition Dharma leads the politicians to absolute power and we are now facing what is absolute corruption. Sadly, the insensitivity towards stopping this absolute corruption is now making the Buddhi present in the Indians obsolete; and we all know that a country can exists only if there is some Buddhi in its citizens.

To conclude, like the current version of Coalition politics, this article is a jugaad of weird stuff that comes to the mind. I couldn't help it. All what I see in the current version of coalition politics was a big time jugaad to ensure a better loot. Have a nice look at Jayalalitha's offer to UPA II, the operation Kamala and Jharkhand alliance of the BJP with Soren, Mamta and DMK calling the shots in UPA II. Coalition is fine, but good coalitions are becoming as rare as good politicians. This feeling of spiraling down in a bottom less pit is making me really sick and hence this sick blog post.

Moving from Sophia Antipolis to Nice

2010-11-07T23:32:00.035+05:30

This week I moved from Sophia Antipolis to Nice. The reason was I needed a change; a change from my monotonous schedule. I was getting used to being in Sophia Antipolis and I was worried that I am being addicted to the relaxed life in Sophia Antipolis.

Staying in Sophia Antipolis was literally and figuratively a breath of fresh air. My studio was really nice and close to INRIA. Being close to INRIA was a big plus point as I was not worried about missing the buses while coming to work. However the lack of buses on weekends was one my reasons for moving out. I was also worried that I was making my studio a cocoon and it was time that I came out from my cocoon. The more I delayed it, the more difficult it would have been to get out of it. These feelings are similar to the ones I heard about the X+1 syndrome. I had delayed my move by about 1 year and I realized I was slowly becoming a slave to procrastination.

Sophia Antipolis was really relaxing and it had life in the form of birds, foxes (I saw a baby fox on my way back in 2009 winter) and wild boars (which I did not see during my stay). Nice on the other hand is a micro version Mumbai. A city close to the sea and people crowding the bus stops from 7 in the morning; peak hour traffic from 6 in the evening and night-life till 5 in the morning. I had visited Nice many times and I fell in love with the sea the first time I saw it while my plane landed at Nice. I had always love the sea, thanks to listening to my mothers childhood memories of Kundapur and having the swamps between Diva junction and Thane as an indication of being close to my uncle's home in Mulund.

My first weekend at Nice was the Diwali night and I cannot forget it as Hu Jintao decided to spend his Diwali in Nice. The 2 hours it took me to reach Nice from Sophia Antipolis reminded me of the the 3 hours it used to take me from ITPL to Vijayanagara when the BBMP decided to experiment with the Magic Box at the Cauvery Junction. Thanks to Hu Jintao, there were police everywhere in Nice and yes they appeared stressed and frustrated. I had seen similar faces during the bandobasts I used to see in Delhi and Pune.

To conclude, I guess the jitters of doing something different, something new, and the hope of having a nice time in Nice have resulted in this post. I just hope and pray that I perform better when I am living in Nice.

Stages of grief

2010-09-08T22:36:00.021+05:30

This is my log on the stages of grief I went through yesterday. I normally tend to see the page on stages of grief when I am really upset. Externally I try to remain calm, but at times it is hard to hide all emotions. Normally each one of us tends to pass through these phases beginning with

1: Denial.

I received a call from my sister at about 6 in the morning giving me the saddest news I heard this year. At first I thought I was strong but at night I realized it was basically denial. I was resisting the feeling of sadness by mentally saying everything is fine, I have to be strong, I have to continue as if everything is normal and I should go ahead with my University registration (I had taken an appointment the previous day for paying the fees). I couldn't concentrate much but once I paid my fees I ran for the French lessons at INRIA. The teacher had arrived and the lesson was over like a dream. I couldn't remember much but I realize I answered most of the questions. It was fine till the end of the lesson when I decided to go for the blood donation at INRIA. The form needed to be filled in French and I asked them if I could take my friends help but they said no. I got upset, and I brought my friend and requested them but they said no! This triggered my next stage

2: Anger.

I closed my office door and I was upset. It was a combination of anger, helplessness, and irritation to the drizzle outside. I went to the library and issued a book and I got upset because the first few pages were coming out when the librarian gave me the book. I brought to her notice but she said it was fine. I didn't know how to react but starting mumbling when I got out of the library. I felt like pulling my hair while reading the book as I could not concentrate. This is when one of my lab-mate saw me; I guess she realized something was wrong and she asked if I was okay. I said yes and decided to browse some photos I had taken last week.

3: Bargaining.

Browsing the photos I wished if my parents could be with me. I wished they could travel with me. I felt home sick and felt like being with my uncle, my cousins, and my friends. I wished I could have stayed a few more days in Bangalore during my last trip! The very thought of visits to Bangalore not being the same triggered by my next stage.

4: Depression.

I felt helpless and wanted to be alone. I couldn't read the book I had taken and the photos takes seemed awful. The colors in the photos because of the rains frustrated me. I took some hot water but even that felt odd. I wanted to take sugar, but couldn't. I felt hungry as I had not taken lunch. However, the very sight of food reminded me of the words "Hotte Paksha" (Group of Food Lovers). The echoes in my mind and the silence that followed was deafening. Even my lab-mates were quiet in their respective rooms. At times every second felt like a day and at times minutes felt like a second. I just couldn't concentrate on anything and I felt like doing nothing. Everything felt useless, and I felt helpless. I then called by mother.

5: Acceptance.

I called up my mother and talked to her for about 20 minutes. The word "Hotte Paksha" came many times but then I started thinking about cousins. I chatted with a friend of mine at India. My hands were loosing sync with my brain and I do not remember what I typed. But then, after some time, I could get hold of my thoughts before they were typed. I then had the courage to talk somewhat patiently with my father who was the most affected by this. I couldn't talk with my cousins and I didn't have the courage, I talked to them in a few days. I chatted with my cousin in US, and talking with him changed everything. He appeared calm as ever. He had been through what my cousins were undergoing. I then realized I had to move on, we all have to move on. Such things happen and are not in our control. It was not like the feeling I had in the morning; this time I was not trying to run away. I was getting a hint of how heavy it is on the heart to actually move on. I still feel helpless but then I know I am helpless to these kind of things. I cannot change what has happened, but I still have some control over what happens next....

Where are the reporters?

2010-08-13T17:55:00.049+05:30

One of the best essays questioning the credibility of reporters is the one titled Reporters and Parrots by Peter Norvig. In this essay he highlights the most important thing that all reporters must to do, which is to think. Sadly thinking is the only thing that most reporters do not do, they are masters of everything else.

Running the Moss Tool on News Articles

If you look at most of the news articles, you see that the content is the same. I guess this is pretty evident on the success of google news which can easily identify the primary story of a news article and show you tons of other sites showing similar stuff. If a CS professor were to run moss he would have rejected most of the news articles for lack of authentic content.

As the reporters do not think, the presentation of the content also has to be similar. One of the best spoofs that presents the template of any news item was given by Newswipe. You just need to add the content what a PR firm gives you and voila you have a news item that can be bombarded on humanity for the next 24 hours!

How hard is thinking?

The eagerness to show that they were the first ones to have their hands on a particular content shows how less the reporters think. I wonder how many of the news channels have a copy of wikileaks content? How many know that the content is 3.8 GB of war logs? How many Indian reporters actually read even one log of the 35 logs mentioning the ISI? Do they know how many articles mention India? It takes a wget, tar, and a grep command to get all the information you need. But I wonder how many reporters actually did this before jumping in the bandwagon of being the first to point fingers at the ISI. Sadly this takes effort of one night to do. It is not the same as getting a copy of the speech written by a bureaucrat and read out by creatures who have reversed the process of evolution to transform from a human being to an inanimate rubber stamp.

The lack of thinking also shows how deep the marketing and PR firms have penetrated the fortress of journalism. The reporters are just vomiting the content fed by the PR firms. In my previous post of Common Wealth Games I gave an example of the following two interview clips. The reporter in question is one of the few reporters for whom I have (or had) a lot of respect. The preparation for the interview was minimal and she was satisfied by answers for which even a 6 year old kid would find flaws. Her expressions and her nods show her willingness to not think. Also have a look at what is being flashed in bold. In this case it is pretty evident that they are flashing what Kalmadi Inc want to be shown, i.e., "Perception of India is very good abroad" and "All we have done is transparent". The mascot in the background shows how much pain Kalmadi Inc have gone through to ensure a perfect setting for a nice 10 minute ad to show everything is fine and pure as the river Yamuna flowing from Delhi to Noida.

As Peter Norvig mentions, good reporters are extremely important. They are so important that one of the first things done by the great freedom fighters was to setup a press; the Kesari and the Harijan newspapers are the best example of this. Sadly given the current state of reporters and journalism, it will take a miracle to save journalism from reporters who have sold her to the pimps in the PR firms.

Testing math

2010-08-11T23:46:00.007+05:30

$x^2+C$

Wow this works!!!..

$e^{x} \frac{sin(x)}{x} = x $

NOw for more equations and

$2x^{2} + \int_{x=1}^{\infty}$

The Great Indian Tamasha: Common Wealth Games

2010-08-10T20:35:00.031+05:30

Some time last week I burst out laughing after lunch while reading an article. I guess it was the this one, the one with pots worth 43 lakhs. When I told my bemused labmate that the scarry laugh was regarding the corruption at the Common wealth games, he looked even more confused and gave me the most common italian hand gesture.

Publicity यह क्या है?

During this gesture I realized the amount of the so called crappy publicity this games gives. This is not the Olympics, this is not even the Asian Games; this is some event where countries once under the military presence of a common country come together. I guess it is like Iraq and Afghanistan hosting an event titled Bush tried to screw me games. Just like no other country will watch those games, these games wont be watched by anyone else. Apart from the cricket playing nations I guess no other country will ever know what happens in the first two weeks of October in Delhi. And to publicize India to these countries you don't need these games you have the bigger and sleazier tamasha called IPL.

Well having games is good. Calling it pride of the nation is good. However, giving it a blank cheque is bad. Disgracing yourself to the extent where your behavior is no different from a parasite surviving on shit is bad. There were corruptions in South Africa, there were corruptions in China as well, however the guys there were not absolutely corrupt; making money was not their primary objective, they were actually keen in hosting the respective events. In case of the common wealth games, I guess as the name suggests, most of the deals followed the golden moto of Indian civil services "सब का पैसा हो अपना". While making a tantrum over the games, the opposition is just saying "और मेरे लिए? ५% से कम नहीं लूँगा."

The Tamasha by Indian Media

The media is even funnier. The funniest video I saw was this one by Barkha Dutt; the very Barkha Dutt that once went to Kargil.

1. Look at the message being displayed. It is like an ad for Kalmadi Inc. How can you say image of India is good. It is like saying that every cow in a country is white when you come across one white cow.
2. Where are the minutes of the meeting with the London police which tells in the last minute that unless you add these security issues we will not let the event go smoothly?
3. How did he get a forged letter from the High Commission? Who is responsible for this forgery? Just think, if one government organization receives a forged letter from another government organization then who can ensure the documents in hand are the original ones? What is the result of the inquiry? International relations are at stake when forgery happens at an Indian embassy.

1. The newsreporter does not even know what prices she is talking about? Just by saying these air conditioners are bigger the matter is closed. What about air conditioners in the airport? What is the price difference in this case? No questions.
2. Nations pride using German treadmills? When everything in the planet is made in China we rent a treadmill for 3 to 4 times the price it can be bought and bring a German technician with it. Isn't there a single Indian from 1 billion people who knows the internals of a treadmill? Now how could Barkha Dutt be satisfied with this crap.

Did they learn any lessons from the Common Wealth Youth Games in Pune?

The even funnier thing is the complete lack of coordination. It was pretty much evident during the Commonwealth youth games in Pune. One fine day they lay concrete. The next day the decide they have to digg the concrete as they did not lay pipes for the telephone cables.

In the above picture you can see faint orange lines behind the trees. It is clearly visible above the "et" of the get set go slogan. These orange lines are the pipes with fiber optic cables of ISPs. These are just hanging and have been hanging till the time I left Pune last September (almost 1 year after the Common wealth youth games).

Lessons in pride.

Our dear Delhi CM Dixit recently said she was worried when she visited China before the games. Ok despite we all know that China was prepared about a year before the event let us assume what she says is true. So what if China was not prepared? It doesnt mean you should imitate China. It is like you are openly saying India follows China. How patriotic is her statement now? It is like saying Zardari is in UK when his country is reeling under floods so Manmohan Singh can go on a 50 day silence when Manipur and Nagaland are blocked.

To be frank the games are showing what we truly are:
1. A nation where there is no leader and anyone can do whatever he wants. So long as you have money you will get away with it. There is no one to take complete responsibility of anything but everyone wants to take credit of even the smallest achievement.
2. If there is anything from which a commission/bribe can be taken, it will be taken in India. I guess it is time we have "ऊपर का पैसा 101" courses in all colleges, why restrict such lesson to the IAS cream.
3. १०० मै से ९० बेईमान फिर भी मेरा भारत महान.

Well we have the Independence day this week so, despite the fact that our military generals make money of the rations of troops being stoned, despite the fact that from birth certificate to death certificate we come across दलाल's, we have to be proud. Proud not because of the 90 corrupt but because the 10 who are not corrupt are absolute gems. I salute to those 10 gems who despite being surrounded by these 90 parasites shine brighter than any star in this universe.

Mahabharata and Indian Politicians

2010-08-05T18:31:00.041+05:30

I would like to begin by saying, "We read our history and mythology as stories. Rather than learning from them, we forget them like the dreams that awaken us to the very reality that we have created."

Last Sunday I came across the Mahabharata episodes on Youtube. Thanks to Rajashri, the production house that is famous for selling marriage videos as 3 hours movies, the entire B.R. Chopra master piece is available online. There is an age old saying that if there is anything possible in this world, it can be correlated to the events of the Mahabharata. I guess this is one of the reasons why even the great Oppenheimer quoted the Gita after the Trinity test. However, reading the news articles after seeing the Mahabharata I could see the Mahabharata in modern day politicians. I guess each one of us has such moments but I thought of writing my thoughts.

One of the biggest problems in current day Indian politics is that there is no leader and no successor. Sadly, this problem also has its roots mentioned in the Mahabarata. Before Shantanu's marriage to Satyavati the king had to choose from amongst his subjects the one who is most suitable to replace him. The successor to the throne was not necessarily the son of the king. Sadly blinded by his love for Satyavati he agreed to having Satyavati's children as his successor. This is as far as I remember the first occurrence of a child born to a king being nominated as the successor. Call it dynasty politics but this has stuck with India as has now become an Indian culture in politics. I guess Bharata would be glad that it is never referred to as भारतीय संस्कृति. Each of the current leaders and political parties sadly do not have a leader and a true successor.

Dr. Manmohan Singh:
To be frank, I would be wrong if I said he is not worthy of being a leader. In fact, he is the most qualified person and the best person currently alive to lead and run the country. Sadly he is neither running nor is he leading the country. I know silence is golden but at times words need to come out. Think of Arjuna sitting on the battle field and Krishna not speaking. Think of Oppenheimer having second thoughts on testing the bomb. Now think of the children in Kashmir, the soldiers in Kashmir, the tribals in Maoist belts, and all the people being affected by the zillions of problems in India. Words help, and words from a leader have the best healing power. Obama is the best example of this. Sadly what we hear from Manmohan Singh is silence and at times words written by bureaucrats. I am not sure what is compelling him to behave like a Dritarashtra. Why is he blind to these problems? Why is he letting Mamata burn the trains? It is like he has been made a PM because he is the most helpless creature amongst the ministers and the most easily manipulated. How could a great man like him let others treat him like this?

Pratibha Patil:
She is by far the best example of how some women are treated in the country. She is nothing more than a pawn. Replace her with a skimpily clad newsreader put on news channels to improve TRP ratings and the situation in the country would not change. She is to the idea of female liberation what the skimpily clad newsreader is to authenticity of the news. She is like the Dushala, who is the least mentioned person amongst her brothers and has the least say in what her brothers are up to. Even if we assume she is innocent, if a sister cant control her brothers who are close to her, how can she be fit lead the country? Sadly rather than being a great female leader such as Razia Sultana, Ahilyabai Holkar, Rani Chenamma, and Rani Laxmibai, this leader of the armed forces is the best symbol to advertise India as a soft state.

Lal Krishna Advani:
One of the biggest mistake this person made in his life is not groom leaders to replace him. We have potential leaders like Arun Jaitely, Sushma Swaraj, Nitin Gadkari, Jaswant Singh, and many more. However, not one of them stands out and appeals as a true leader; not one is capable of leading the others I mentioned. A good opposition is essential for democracy, else democracy becomes monarchy waiting for a tyrant to be born. I guess it is a problem of plenty but sadly not one of them is a true leader like Vajpayee who could stand out from the crowd. Further, there is a problem of dynasty politics entering this party as well. The biggest mistake that Indira Gandhi made was there was no one groomed to replace her; yes Narasimha Rao became a PM but the Congress became a shade of its past after his term ended. Now Vajpayee had Advani to follow, but no one after that. The 2009 results for BJP would remind any one the time of Congress under a guy called Kesari.

Now I have mentioned only the BJP and the Congress as the rest of the parties are no longer worthy of being mentioned. CPI I do not wish to mention. Consider what the communist party did to China from 1980 to 2010 and then look at what a communist party did to Bengal in the same time period. Bengal is the state of the greatest thinkers, the greatest artists. Creativity is in the heart of Bengal, hard work is in the heart of Bengal, yet sadly in this very state we have the Communists fighting with Maoists; each trying to redefine social justice and claiming to be on the true side of Dharma.

We the people are the ones who are responsible for this mess. The process of finding a leader and selecting a leader is in our hands and yet we prefer to stay in our houses enjoying the cool air of the fans and AC's rather than pressing a big button. I guess we act like Deedee from Dexters Lab asking the rhetorical question, What does this button do?. Jayprakash Narayan was useless without the crowds that came to listen to him. Abdul Kalam, one of the true presidents since independence, became a demi-god because of the support and faith he enjoyed. Yet despite the power we have we prefer to act helpless. There are many things that can be done. One just needs to listen to ones heart to compile a list of such things. One just needs to perform an action rather than sitting and waiting for some one else to do the right thing.

Network Address Translation (NAT)

2010-08-05T15:18:00.018+05:30

Why do we need NAT?

Well before I start explaining NAT, I guess it is important to know why NAT is necessary. The machines on the Internet use a 32 bit address (IP address) to uniquely identify each other. A machine can communicate with another machine in the Internet so long as it knows its 32 bit IP address. 32 bits implies there can be about 4 billion IP address. This number is far less than the population of this planet, and far smaller than the number of machines that want to access the Internet. A hacky solution to this small address space is to let multiple machines use the same IP address. NAT boxes enable you to let a large number of machines in your home/office/college access the Internet with a small number of (usually one) IP address. A machine behind the NAT box can be in one the LANs (top portion) of the figure given below.

What is a Global IP and what is a Local IP?

In the context of NAT we come across the terms Global IP and local IP address. The IP address your NAT box uses to communicate with your ISP other machines (including other NAT boxes) in the Internet is the global IP address. The IP address of the machines present in the LANs behind the NAT boxes (above NAT box in the figure) is the local IP address. The local IP addresses are typically 10.x.x.x or 192.168.x.x.

How do machines in the LAN access the Internet?

NAT stands for Network Address Translation. So as the name suggests, to the outside world all the machines behind the NAT box are seen as one machine accessing the Internet. Say, machine A with IP address 10.2.3.4 wants to access google.com which has an ip address A.B.C.D and the global IP address you have is I.P.A.D. The NAT box replaces 10.2.3.4 with I.P.A.D. and sends to the packet google. The response from google is forwarded by the NAT box to you. Now if two machines M1 and M2 from the LAN access google, the NAT box needs to ensure that response from google to M1 is forwarded to M1 and not M2 and vice-versa. There are various ways in which NAT boxes do this. The main idea is that the packets between a machine in the LAN and a remote server should not be lost and garbled.

How can machines in the Internet connect to machines behind NAT?

A simple answer to this question is NO. Say a machine A.B.C.D in the internet wants to connect to M1 (10.2.3.4). Now note that 10.x.x.x and 192.168.x.x addresses are reserved for machines behind the NAT. So if you have a NAT box in your house/office, you can assign 10.2.3.4 to a machine behind your NAT box. Similarly, your neighbour can buy a NAT box and assign 10.2.3.4 to his machine. So when A.B.C.D wants to connected to 10.2.3.4, how can a router in the Internet tell that it needs to connect to your machine M1 and not your neighbors machine.

What is port forwarding?

One way a remote machine with address A.B.C.D can to your machine 10.2.3.4 is by connecting to you NAT box. The source address of the connection request is A.B.C.D and the destination address is I.P.A.D (the global address of your NAT box). The NAT box can then be configured to forward requests on a particular port to 10.2.3.4. Say you want to run an HTTP server on M1 (10.2.3.4) behind the NAT box. The NAT box can be configured to forward connection requests on port 80 to 10.2.3.4. This is one way in which a remote IP in the Internet can connect to machines behind the NAT box.

NOTES
The contents of this post are simplified to a large extent and some technical content needs to be taken with a pinch of salt.

Articles to Read:
[1] http://www.ietf.org/rfc/rfc1631.txt

[2] http://www.howstuffworks.com/nat.htm

[3] http://en.wikipedia.org/wiki/Network_address_translation

An Automatic Paper Submission Engine for Improved Acceptance Ratio

2010-07-24T23:39:00.029+05:30

Abstract

In this paper we present an automatic paper submission engine that aims at improving the acceptance ratio of any conference. We create a random title picked out from words chosen from the titles present in the proceedings of popular conferences such as SIGCOMM, SIGMETRICS, SOSP, NSDI, and Infocom. We then pick random sentences from the abstracts of these papers and create an abstract of at most 5 sentences. We then extend this algorithm for section names, section content, and even create an appendix with incomprehensible equations; we also add an acknowledgment to acknowledge all the machines used to generate the paper. We believe that this technique when integrated with any conference managing software can do wonders to improve the acceptance ratio of any conferences, especially those that no one has heard of.

Introduction

We keep the rest of the content hidden from the reader due to shortage of space :).

The infinite monkey theorem

Acknowledgment

The 5 sentence abstract given above was generated by a monkey randomly clicking on the keyboard [1].

References
[1] Monkey1, The infinite monkey theorem, in the proceedings of First International Conference for Intelligent Monkeys.

Scheduling Jobs without Cron: Using at or batch command

2010-04-21T19:32:00.007+05:30

Cron is one of the most widely used job schedulers in the *nix systems such as Linux. However one needs to add jobs in the crontab file to schedule the jobs and this is not possible (typically) for users without super user privileges and not having privileges of being added in cron.allow. For such users job scheduling is possible with the help of the batch/at command or (batch command). An example for using the at command to schedule the execution of the file present at /tmp/test.sh is as follows:

For example I am using program that touches a file in a given directory. So I create the /tmp/test.sh file by executing the following commands
#> echo "touch /tmp/abc.text" > /tmp/test.sh
#> chmod +x /tmp/test.sh

To use at, first make sure that the atd deamon is running, which is the daemon that is responsible for scheduling the jobs.

#> ps -ef | grep atd

Now schedule the job test.sh at say 03:00 tomorrow

#> at -f /tmp/test.sh 03:00 tomorrow

The output will be something like

job 1 at 2009-11-05 03:00

The process will execute /tmp/test.sh at the given time. Do a 'man at' for a glimpse of the complex time specifications such as tomorrow, or +3 days, which are possible with the at command. Some of the examples are as follows:

#> at -f /tmp/test.sh 03:00
#> at -f /tmp/test.sh 4pm + 3 days
#> at -f /tmp/test.sh 12:00 july 15

The list of jobs can be viewed using the atq command

#> atq
6 2009-11-05 02:00 a username
5 2009-11-06 04:00 a username

Removing the 5th job from the above queue is simple. Execute

#> atrm 5

#> atq
6 2009-11-05 03:00 a username

Hope this is useful as I was not able to find a simple tutorial for the 'at' command. I guess its difficult to google search 'at' :).

The IPL experience

2010-04-21T19:27:00.002+05:30

Watch IPL live on youtube.com/ipl was the paint on the Vayu Vajra bus that brought me from the heart of Bangalore to the flashy Bengaluru International Airport during my recent India visit. Seeing the ad made me happy as I could watch these matches in France. To be frank the last few weekends have been fun as I prefer to watch the matches held on weekends. But given the events of the last few days I might just skip the matches.

The overall experience of viewing matches on youtube was good, however there were a few things that irritated me during these matches. The most irritating was the blimp and the commentary, *** has been at the forefront of technology. Are the commentator and the marketing firm of *** serious. They could have picked another better tag line related to the pace foundation or the bat wielded by Sachin, the Alchemist, for the last couple of decades. The funniest thing was, irrespective of the match, irrespective of the venue, and irrespective of the cameraman, the video clip used by the commentators was always the same. How perfect can a cameraman be, and how perfectly similar can the weather conditions be? in short how can the cameramen at different venues get the same view? I believe there is no blimp and this story in a way confirmed the absence of the blimp.

The second thing was the constant blabbering of *** Kamaal, *** moment of success, *** timeout and all the crap we are bombarded with. Now the saddest thing was that even in the awards ceremony I heard Kumble say, "It is nice to win a *** Kamaal even at this age". Because of my respect towards to the greats such as Sachin, Dada, Dravid, and Kumble, I am censoring my words matching *F*; but at times I cannot control it. Luckily youtube has fewer but highly irritating ads; irritating because the volume suddenly shoots up virtually tearing the eardrums. The most irritating is the one in which a biker jumping from one ship to another to reach an island full of bimbos playing the holy and peace loving game of beach volleyball.

But this IPL gave me a proud moment as the Pune team was bought for about $370 million. Yes $370 million. Now the funny thing is, while mentioning the amount, a good number of the English dailies preferred to use $ and millions as the currency compared to Rs and most importantly the colonial standard of Crores in their website. I know RBI is yet to decide on the symbol of Rupees but why $, why not £, ¥, or €. Also $370 million for Pune? Seriously? Why? Why not $1 billion? How did they come to this magical figure for a city which is famous for its Sawai Gandharva (सवाई गंधर्व) and Natak (नाटक -plays) and NatyaSangeets (नाट्यसंगीत - operas) and most of all the Puneri Patya(पुणेरी पाट्या).

Speaking of Patya, the press has been very busy with the P's lately. Apart from the pictures of Shoiab Malik who refused to use skype and get married to a girl based on his trust on BSNL, the most important news flashed on google news was the true P in IPL. Here are a few P's that I came across.

Paisa or should I say Penny: I guess this needs no introduction. Given the amount of money exchanging hands and most of all the amount spent on motivating Harsha Bhogle to grow, weave, or transplant hair like our ageing film stars.
Politics. Well this blog by Prem Panicker details on all the stories ranging from Dial M for Modi/Mauritius/Money, the perils of a news daily which act like a parrot and not a reporter, and the hair pin bends in the life of Shukla, the potbellied face of Indian journalism. Some newspapers articles are also well written which give a better insight on these issues; the articles I liked are available [here] and [here]. All of this makes me glad that Shashi Tharoor was not selected as UN Security General; just imagine the disgrace - if he was the Security General he would have acted like the pet dog of US for a few meaty bones.
Privileged. One most important point is the split IPL is creating. Most of the teams are based out of towns that have a bigger English speaking base; for example, Bangalore, Mumbai, Pune, and so on. These are representative of the states which are doing well. We do not have a team from the North-East which has produced great footballers like Bhutia but cricket seems to have not reached there. I guess the primary purpose of a cricket board and to sustain a league is to spread cricket to these areas and motivate new talent by giving them steady incomes. Imagine the development IPL can bring to a state of Bihar. Even Jharkhand, the state of our cricket Captain, Dhoni, does not have a team. I guess no one bid for Tatanagar or Jamshedpur and yet we have to bear ads like this.

On the lighter note, it is ads like these had made the past IPL experience really funny while the excessive ads in the current version have made the viewing experience pathetic. The sixes have become *** maximums, the catches *** Kamaal, and wickets *** moment of success. What is remaining is having an ad for single, dot ball, no ball, wide, and third umpire calls for run-outs. In any case I guess it is a matter of time when all of this IPL business converges to something comprehensible and sustainable.

Sania's Swayamvar (सानिया का स्वयं‍वर)

2010-04-18T20:09:00.032+05:30

This week the tennis star and the poster girl of many Indians decided to get married. Yet, compared to the fake marriages one is being bombarded on reality shows, her marriage or should I say Swayamvara (स्वयं‍वर) was more entertaining than all soap operas put together. In fact, her marriage was more controversial than her short skirts and the fatwas that tried to lengthen them. More-soever, the time she managed to stay in the limelight was definitely much more longer than the time she currently spends on the tennis court.

What worries me most is that this is a celebrity marriage, whose average length can be computed before a complete scan of the page three of any newspaper. And speaking of loyalty this marriage has its foundation in dis-loyalty as both the bride and the groom were respectively engaged and married to someone when they started seeing each other. In fact based on Shoaib's statements, he was seeing two girls; one supposedly fat and the other whom he called thin, beautiful, and the younger sister of the former; is he trying to say he was involved with two sisters...yuck! Based on these incomprehensible statements the funnier thoughts that came to my mind were based on Shoaib Maliks behavior. How stupid can a guy actually be if he thought his first wife was the elder sister of the bride he married over telephone. Then he backtracks and says he is divorcing her because she was fat. Now, couldn't he just fly to India or have the marriage held in a neutral venue like the US or UK; but no he wanted to set an example of being desperate by marrying a supposedly hot girl over phone (Didn't he hear of Skye, it free you dumb ***). Based on all these desperate behaviors of both the bride and the groom, it will take divine intervention to ensure a happy married life for the couple. However, for the sake of peace between them and the countries I have to wish them a happy married life.

Now coming back to Shoaib and the Siddiqui family; I cannot help speculate that all is not well in cricket. Siddiqui being an Indian and based in Saudi was able to get his chubby little girl move around easily in Dubai and according to Shoaib masquerade another girl as his daughter. He also hosted parties for the Pakistan team in India. All of this along with the Dubai connection has got to appear hazy to anyone who has his eyes open. This Dubai connection makes me really scared thanks to videos of Anu Malik and Kumar Sanu singing praises of Dawood; link between Miandad and Dawood; the statements of Hansie Cronje; and all dirty things about Sharjah as a venue for Indo-Pak matches thanks to our honorable MP Azhar and his accomplice Jadeja. Thanks to all these hazy deals, one cannot consider Shoaib to be as Pak (pure and holy) as his chocolaty looks. In fact I find it difficult to believe his innocence given the amount of money, speculated to be Rs 15 crores, he gave of to break his past marriage.

Given all these complexities, the head of PCB would be a fool to have, either a stupid guy who marries of a phone or a potential match fixer given the money exchanging hands, in a team supposed to represent a country; but then the PCB has turned a blind eye to the Miandad controversies. Also I am really scarred as the couple are extremely media savvy. God forbid, but if anything goes wrong in this marriage, then there is a high likelyhood that both of them, and all their stupid fans and the media, will blow the their personal issues out of proportion to create tension between the countries. In fact I would like to stop here rather than increase the incoherence of this post. Since Shoaib likes technology in the crude form, I would like to send a telegram code 25 and 17 for the couple. And for the sake of peace I am hoping to send code 30 in the following years to come.[Here are the telegram codes: Best wishes on your wedding anniversary - 30, May Heaven’s choicest blessings be showered on the young couple - 25, Wish you a happy and prosperous wedded life - 17].

JDIR Experiences

2010-03-29T21:18:00.014+05:30

I was attending JDIR from March 24, to March 26. This was the first time I was presenting a paper at such an event and I was not sure on how to go about it. Most of the presentations were in French and I was afraid of being the odd man out. My presentation was on Friday, March 26, and my advisor, Arnaud, and my lab mate, Stevens, had given me nice feedback about my presentation on Thursday. I missed the excursion to MarineLand on Thursday as I was busy modifying the presentation.

My initial presentation was in Beamer, however, based on the comments given by my advisor I was tempted to use PowerPoint. Sadly due to my inexperience on Windows and Office, I just couldn't get the effects I needed; hence I stuck to Beamer. I was done with the modification in the night at around 11. The presentation was in morning at 9 in INRIA and I woke up early at about 5:30 to rehearse. It was around 7 when I started rehearsing, and for some stupid reason I decided to practice on Windows. The machine booted and I finished my presentation in about 15 minutes. I had skipped the text I was to speak at the outlines; this was a mistake and my advisors email sent to me during the presentation was a confirmation of this. But as the presentation was over my eyes fell on the clock on the bottom right of the screen; it was showing 8:30. My heart lost a beat. My office mate, Roberto, had warned me that daylight saving time kicks in this weekend. I had read that it doesn't happen at the middle of the week but I thought my computer cannot be wrong as it normally syncs the clock with the timeservers. In the hurry I even forgot to check the current time on worldtimeserver.com.

I packed my bags, took the pen drive which had the copy of the presentation, and ran. Murphy's soul was playing a joke with me as it was pouring like it does in Mumbai while I was rushing to INRIA. My phone, which was manually set and doesn't understand day light saving, was showing 8:45 when I reached the INRIA gates. I swiped and my card gave an error. I was petrified; my card stopped working on the day of the presentation, 15 minutes before the event; I thought I was screwed big time. The guard, with his big white beard which will remind anyone of the foreigners representing the East India Company, came out with a frustrated look; it was quite natural as no one would want to begin their day with some problem. He showed me the time; it was 7:45 and he said my card would be activated only at 8. The guards office had been shifted to another conference room that day and he was kind to offer me a seat near his table.

I reached my office at 8 and left for the conference hall at 8:30. My slides were copied on the notebook connected to the projector and I confirmed that the latest version was copied. The presentation went fine and during the course of the presentation I realized I was talking in my normal pace (which is very very fast) . I slowed down and decided to concentrate on the pronunciation of the words. Overall the presentation went fine, however, for reasons unknown, while answering the questions I realized my pace had returned. My advisor was present for the presentation and it was nice as my mailbox had all his feedbacks and the time at which each of the feedback was sent. Stevens, my lab mate, also had a presentation that day and his presentation was amazing; he won one dolphin as an award for his presentation.

However, the JDIR had stored the a surprise for the end. After the event was over, I was approached by a guy who had asked questions about the error bars used in the plots and the TCP implementation for which the experiments were conducted. I was impressed as most of the other crowd just wanted me to finish (I guess my accent and pace had a lot to do with this); but this guy was unfazed. He was a French national and when we met me, he asked from where I was. My reply was India, but he was not convinced and asked, which part of India. On receiving Mumbai for an answer, he asked if I was a student of IIT Mumbai. I said that I was a masters student at IIT Delhi. His face lightened and he said that even he was a masters student at IIT Delhi. I was shocked. Here in INRIA Sophia Antipolis, I am meeting a French guy who said he was a masters student at IIT Delhi. He was an exchange student from EPFL and spent 1 year of his masters in the Maths Dept at IIT Delhi; he was currently a part time student at Eurecom and was working in Orange Labs. I felt really glad as I had met a French national who was in India for his masters.

Overall JDIR was really an amazing experience for me and I am hoping to publish another paper in JDIR.