#!/usr/bin/env bash # Arvinder Singh Kang # askang@olemiss.edu # Version 0.1 - 2009-06-02 # ipaddress: This snippet returns the ipaddress of the current computer. Store in a directory which is in the PATH, and make it executable by running "chmod +x ipaddress". # Running command ipaddress should return ipaddresses of this machine.

ifconfig  | grep -E 'inet.[0-9]' | grep -v '127.0.0.1' | awk '{ print $2}'

However on booting a client from the NetBoot server, i got the following sign on ppc client machine

After reading some notes on NetBoot here, I found this reason:

The mach.macos.mkext file is a kernel extensions cache — a file containing all the important kernel extensions for basic network booting. Its fairly uncommon to run into problems in this stage of the Netboot process, however, there are a couple specific issues that can cause kernel panics at this point. Possible problems would be:

Not having a mach.macosx and mach.macosx.mkext file in your Netboot set

And when checked mach.macosx.mkext was actually missing from the nbi’s dmg file. So I generated one using following code

kextcache -a ppc -m /Library/NetBoot/NetBootSP0/DeployStudioRuntime-091207-145110.nbi/ppc/mach.macosx.mkext -N -L /Volumes/DeployStudioRuntime/System/Library/Extensions/

And my netboot imaging operation was back in business. Ahhh…. Freshly minted macs by the time I walk in tomorrow morning.

Update March 6, 2010 : As the unrooted phone does not allow change in the phone ROM, this would only run on rooted phone. Here are five reasons why you should root your phone. One way to do it, is listed on CyanogenMod wiki.

I use Google G1 running Android OS for my email. To enable Punjabi on android I used the following steps

1. Download a Unicode Punjabi font.
2. Copy this font to your sdcard and rename it exactly DroidSansFallback.ttf.

Now start Terminal Emulator and type exactly (watch the Case) the following commands, followed by enter.

su (then wait for the superuser screen and press yes)
mount -o rw,remount -t yaffs2 /dev/block/mtdblock3 /system
chmod 4755 /system/fonts/DroidSansFallback.ttf
dd if=/sdcard/DroidSansFallback.ttf of=/system/fonts/DroidSansFallback.ttf
reboot

Voila you should be able to read Hukamnama and emails written in Punjabi.

Thanks to Droidbot for the idea

While bringing up firewalls for my test server, I thought of doing a little check on my machine. The logs raised both my eyebrows. Dear Google told me, I was not the only one.

Leopard introduced application based firewall, while the old ipfw still exists with just one default rule (Accept everything from everything!)

65535 allow ip from any to any

So with Application firewall doing its best, lets add some ipfw rules. One way to do is making and adding new rules. However Newton said “Pigmaei gigantum humeris impositi plusquam ipsi gigantes vident(If I have seen a little further it is by standing on the shoulders of Giants.)”

So I downloaded the tested ipfw rule list from securosis.com to start with and tweaked to my taste, and imported the file into WaterRoof, an ipfw frontend.

To check your ipfw rules, use “sudo ipfw list“. When you’re satisfied with your rules, install them for future reboots with “Tools > Rules Configuration > Save to startup configuration” and “Tools > Startup Script > Install Startup Script”.

I also installed WireShark, originally known as Ethereal, but could not get it working. However a look at network log is much more satisfactory now than before.

Image: Cedalion standing on the shoulders of Orion from Blind Orion Searching for the Rising Sun by Nicolas Poussin, 1658. This image is in the public domain.

Once your OS is grown enough to play (I mean installed), you have to sit down with it and do the SECURITY TALK.

A little on the philosophical side of it, I think sense of security is just a fad and a perception. You are secure when you start feeling it, or we can keep on going paranoid tweaking it deeper and deeper, there will always exploits to to be known, more tools to be learnt, more WMDs to be discovered!

Always have a second plan- backup your data.

Lets get back to our Linux Box.

One of the requirements that our installs are going to have is a mail server. The linux box can email me complaining it has stomach ache, or any activity that goes on it.

TechRepublic has an old, yet not obsolete article for recipe indegrients of a mail server. We just need postfix.

After some reading about postfix, here is the route I took

$ sudo aptitude install postfix

Now head over to the postfix configuration documentation and tweak the settings. The only change I did was to make sure that my server is relaying mail originating only from local machine.

$ sudo vi /etc/postfix/main.cf
    mynetworks = 127.0.0.0/8

Save and exit. Now reload the changes.

$ postfix reload

Remember? We had put up a firewall on this box. However, nmap scan from another machine shows port 25 open (smtp being used by postfix.) Lets add some rules. User --dry-run to test command syntax.

sudo --dry-run ufw deny proto tcp from 0.0.0.0/0 to xx.xx.xx.xx port 25
sudo ufw deny proto tcp from 0.0.0.0/0 to xx.xx.xx.xx port 25

I think, I’m not as happy with ufw. Its good for starters, however it does not have advanced flexibility. I’m going to return to Shorewall within coming weeks.

Although linux machines hardly have the risk of being affected by viruses, still they can be threatened by trojans, worms by a vital part replaced by a rootkit.

chkrootkit is a tool to locally check for signs of a rootkit.

$ sudo aptitude install chkrootkit  
$ sudo chkrootkit

The run returned system not infected. Next lets install Rootkit Hunter. .Rootkit scanner is scanning tool to ensure you for about 99.9%* you’re clean of nasty tools. This tool scans for rootkits, backdoors and local exploits.

$ sudo aptitude install rkhunter
$ sudo rkhunter -c --skip-keypress

We came out clean.

Next I should look at AppArmour and GRSecurity. However there are other things crying for my attention. I’ll come back to them later.

The security paranoids can look at top 100 security tools.

Photo credits: GD Senior @ Flickr

I have used SVN in the past, however CVS is still the old faithful dog hosting Drupal repositories. I wanted to concentrate on using Git, while wanted easy way to update drupal installations.

After a number of blog reads, here is my workflow (atleast planned one…)

Lets start by freeing ourselves from typing in password each time and allowing only public-private key authorization.

Password free remote Login

Following is more or less a shameless rip from this article (Here for my own reference).

On my local machine, I already had generated ssh key-pair. However in the ~/.ssh/ folder I found id_dsa, id_dsa.pub pair along with id_rsa, id_rsa.pub pair. Hmmm! A little digging into the man pages revealed the difference between RSA and DSA.

$ man ssh-keygen

RSA uses 2048 for encryption by default and can vary, while DSA used exactly 1024.

Lets copy our public key to the server.

$ scp ~/.ssh/id_rsa.pub myusername@myserver:~/

On my remote server

$ mkdir ~/.ssh
$ cat id_rsa.pub >> ~/.ssh/authorized_keys
$ rm id_rsa.pub

Lets activate the key

$ sudo su -
# vi /etc/ssh/sshd_config

Edit the file ensure following options

RSAAuthentication yes
PubkeyAuthentication yes

Save and quit vim. Relaod the configuration.

$ sudo /etc/init.d/ssh reload

Now if we access the server from my client machine, it does not asks for a password.

Lets disable authentication by password, to shield brute-force attempts.

$ sudo vi /etc/ssh/sshd_config

Edit the file ensure following options

....
ChallengeResponseAuthentication no
PasswordAuthentication no
UsePAM no
...

and reload SSH configuration file:

$ sudo /etc/init.d/ssh reload

Thats it. A machine with a differnt private key would not be able to log in.

I also thought of making my official GnuPG/PGP Encryption key and putting it up on the website. But thats for another day.

**Back to our main topic – Git-svn workflow **

(Inspired by Version Control Blog, ToolmanTim and Aidanf).

On my local machine

$ mkdir -p ~/src
$ cd src
$ cvs -z9 -d:pserver:anonymous:anonymous@cvs.drupal.org:/cvs/drupal checkout -r DRUPAL-6 drupal
$ cd drupal
$ git init
$ git add .
$ git commit -m  "The inital commit of drupal6 core presently at version 6.10"

Now lets login to server, where we want to host the git repository for redundancy.

$ ssh myusername@myserver
$ mkdir -p ~/gitReps/drupal.git && cd  ~/gitReps/drupal.git
$ git --bare init
$ exit

Back on our client machine

$ git remote

Nothing returns. Good we are on right track.

$ cat .git/config

Returns

[core]
    repositoryformatversion = 0
    filemode = true
    bare = false
    logallrefupdates = true

Lets add remote repository.

git remote add myTux ssh://myusername@myserver/home/myusername/gitReps/drupal.git

Now above command will return

[core]
    repositoryformatversion = 0
    filemode = true
    bare = false
    logallrefupdates = true
[remote "myTux"]
    url = ssh://myusername@myserver/home/myusername/gitReps/drupal.git
    fetch = refs/heads/*:refs/remotes/myTux/*

Running git branch shows just one branch locally

* master

Lets push this to our remote server

$ git push myTux master
Counting objects: 703, done.
Compressing objects: 100% (636/636), done.
Writing objects: 100% (703/703), 1.13 MiB | 1600 KiB/s, done.
Total 703 (delta 29), reused 0 (delta 0)
To ssh://myusername@myserver/home/myusername/gitReps/drupal.git
 * [new branch]      master -> master

That is our first drupal repository. It would only carry drupal bare-bone code. Any update to drupal-core will be applied here as follows.

Clone the drupal on local machine and update from drupal using cvs. Then update the git and push the changes to remote server.

$ git clone ssh://myusername@myserver/home/myusername/gitReps/drupal.git
$ cd drupal.git
$ cvs update -r DRUPAL-6.11 -dP
$ git status
$ git add .
$ git commit -m "Drupal core updated to version 6.11"
$ git push myTux master

Now lets create two other seperate clone of this repository. drupal-and-modules.git would keep updates repository along with updated modules and themese. drupal-production.git would keep code ready to be deployed. (I was wondering if some workaround with using branches can solve it? Any suggestions?)

On the server

$ git clone drupal.git drupal-and-modules.git

On client machine

$ git clone ssh://myusername@myserver/home/myusername/gitReps/drupal-and-modules.git
$ mkdir sites/all/modules
$ cvs -z6 -d:pserver:anonymous:anonymous@cvs.drupal.org:/cvs/drupal-contrib checkout -d sites/all/modules/cck -r DRUPAL-6--2-1 contributions/modules/cck
$ git add .
$ git commit -m "Imported cck 6-2.1 imported"

Now lets push this changed drupal to drupal-and-modules.git on remote server.

$ git remote
origin
$ git branch
* master
$ git push origin master
Counting objects: 343, done.
Compressing objects: 100% (306/306), done.
Writing objects: 100% (336/336), 375.90 KiB, done.
Total 336 (delta 37), reused 0 (delta 0)
To ssh://myusername@myserver/home/myusername/gitReps/drupal-and-modules.git
   046640c..dc5c0c3  master -> master

This updates the drupal-and-modules.git.

When drupal.git is updated, drupal-and-modules.git can be updated simply by using command

git pull

Similarly we can maintain a third repository with all the localization and ready for production.

The implementation worked fine and the workflow should work in theory. However I’m pretty sure, it will be polished as I use git more and start using rebasing and stashing.

mpg123 is a real time MPEG 1.0/2.0/2.5 audio player for layers 1,2 and 3.

I was playing with Ruby scripts and needed a command line mp3 player which was not a resource hog.

Steps I took for my OS X (Should work on Linux/Unix box):

Download the latest version from the website.

Untar the archive

tar -xvf mpg123-1.4.3.tar

Compile and install the player

./configure --prefix=/usr/local/mpg123
make
make install

Add the path to .bash_profile

echo 'export PATH=/usr/local/mpg123/bin:$PATH' >> ~/.bash_profile

Load the new path

source ~/.bash_profile

Enjoy playing music from command-line!

 mpg123 ~/Music/Bagho_Bagh_Gippy_Grewal.mp3

Love this phone(or more appropriately “used to love”), because it used to do task “rarest in its times”.

I could use any public WiFi hotspots (My Office and my home included) and route my calls through the internet, and costing me guess what – $0 (To be precise I paid $10 for TMobile@Home service.) So I could talk non-stop to all the hot chicks!! Lol!

However since yesterday it started to show signs of aging.

Long story short, I was searching for a synchronizer using bluetooth. Nokia only makes PC Suite. I have a Mac. And Mac has iSync which is not compatible with Nokia 6086.

Two Google searches later, here is the solution that worked for me. Here is what I did.

Edit the following file using any editor of your choice. I use Textmate (therefore mate), you can use Vi, Emac, nano, or “I’m still a fan of Charles Babbage” editor:

sudo mate /Applications/iSync.app/Contents/PlugIns/ApplePhoneConduit.syncdevice/Contents/PlugIns/PhoneModelsSync.phoneplugin/Contents/Resources/MetaClasses.plist

Add the following code right after 6021 entry.

<key>com.nokia.6086</key>
<dict>
        <key>Identification</key>
        <dict>
                <key>com.apple.cgmi+cgmm</key>
                <string>Nokia+Nokia 6086</string>
                <key>com.apple.gmi+gmm</key>
                <string>Nokia+Nokia 6086</string>
        </dict>
        <key>InheritsFrom</key>
        <array>
                <string>family.com.nokia.series40.bus.bt</string>
        </array>
        <key>Services</key>
        <array>
                <dict>
                        <key>ServiceName</key>
                        <string>com.apple.model</string>
                        <key>ServiceProperties</key>
                        <dict>
                                <key>ModelIcon</key>
                                <string>NOK6086.tiff</string>
                                <key>ModelName</key>
                                <string>6086</string>
                        </dict>
                </dict>
                <dict>
                        <key>ServiceName</key>
                        <string>com.apple.synchro</string>
                        <key>ServiceProperties</key>
                        <dict>
                                <key>MaxEMailLength</key>
                                <integer>126</integer>
                                <key>MaxNotesLength</key>
                                <integer>126</integer>
                                <key>MaxURLLength</key>
                                <integer>126</integer>
                        </dict>
                </dict>
        </array>
</dict>

Download this file and copy it into the following location using cp command.

sudo cp NOK6086.tiff    /Applications/iSync.app/Contents/PlugIns/ApplePhoneConduit.syncdevice/Contents/PlugIns/PhoneModelsSync.phoneplugin/Contents/Resources/

Now bite your nails twice, touch the sacred Aluminum and pray to the chairman God.

WooHoo!! We are ready to synchronize our address book.

Once imported into Address Book, I created an archive of address book with date.

And then I gulped down a glass of milk and resumed watching the movie Amu…….