Writing a Skeleton Linux Security Module

I recently had to write a Linux Security Module (LSM) for one of my research projects and I was surprised to find that there are few tutorials out there and most of them don’t work because of the discrepencies in kernel versions. They’re talking about 2.000.x kernel versions! The only good tutorial I came across was the one on Linux Journal but it assumed some background knowledge (which I didn’t have). So, I had to struggle for a day to figure out how to go about writing the LSM. Hence, this tutorial.

Now, this isn’t strictly a newbie tutorial. It isn’t even a tutorial per se. It’s more like a guideline that will tell you where to look to find what you need. The reason is that if I write something specific, it’ll go out-of-date in a giffy. So, I’ll tell you the process of how I figured out the steps and you can (probably) reproduce them even if the specifics have changed. This might not be the best way to do it but it certainly gets you going. I had to take quite a few detours to get to these steps; so they might save you some time. Ok, let’s go.

Create Ubuntu Live USB in Windows

If you’ve ever had trouble installing Ubuntu because you couldn’t use a CD (because of a bad CD, a thoroughly malicious drive or, as in my case, a small-form CD stuck in your slot-load mechanism), you might want to read this. This mini-tutorial (slash how-to) is going to show you a clean and concise, no-BS mechanism for installing Ubuntu 8.04 Hardy Heron without the need for a CD or a working Linux installation. I didn’t discover this method. Just came across it somewhere and can’t find the link in Google. So, here it goes. (I’m assuming your USB is F: drive)

1. Get syslinux (this will allow you to make your USB active and install a bootloader on it — I used version 3.81).
2. Format your (700M+) USB drive with a FAT32 filesystem.
3. Extract syslinux, go to the win32 folder in the extracted files and execute (from ‘cmd’): syslinux.exe -ma f:  … ‘m’ installs the bootloader and ‘a’ makes it active.
4. Get Ubuntu 8.04 iso image and use an un-archiver to extract it. Winrar works for me.
5. Copy all extracted files to f:
6. Copy f:/isolinux/* to f:/*
7. Rename isolinux.cfg to syslinux.cfg
8. Reboot and boot from your USB drive (you may need to change BIOS settings for this).

Voila! You have Ubuntu working.

Note: Ubuntu 9.10 didn’t work for me. I got to the X part but only a “working” cursor showed with no progress. So, let me know if you get it working with this method.

Gmail, firefox and fonts on Linux

If you’re like me, you’d hate the default look of web pages (especially gmail) on firefox in Linux. I was beginning to think something was wrong with firefox because the rest of Linux fonts look alright. This is what I got after tinkering around for a day. Looks sweet, doesn’t it.

Here’s how to do it:

1. Get webcore-fonts package. It’s fonts from Microsoft but only the free ones. You’d know Verdana if you come from Windows. If you hate Microsoft… well, write your own fonts of the same quality.
2. Get Greasemonkey for firefox.
3. Get Gmail RL Skin Userscript. Very nice script. I did a few modifications for my own use. Here’s my file in case you need it for reference.

Oh, and send a mail to Google telling them to please stop using ‘Arial’ on all their pages. If Verdana isn’t available by default on Linux, other fonts much better than Arial are! You’d think they’d at least look at their pages on a Linux firefox browser. Sheesh!

The hapennings…

Well, it’s been a long time but I’m finally back. The reasons for such a long absence are countless but boil down to just one: I got lazy.

Anyway, here’s what I’ve been working on lately:

• Formal Mathematics (Set theory and logic)
• Isabelle (automated theorem prover)
• LaTeX (lovely, lovely typesetting engine. I don’t need a word processor any more)
• My MS thesis
• My MS research publication (more on this later)
• My “Software Engineering Education” paper – that one’s going to be published by IEEE inshallah very soon.
• And moving my stuff on to linux. I have to live with my conscious

Well, enough for the time being.

Yum, Yumex and Kyum

One of the problems I always faced with linux was the installation of new software. I’ve been trying to get a good lisp IDE installed for more than three weeks – without any success.

The answer is ‘yum’. It’s a wonderful tool for installing software on linux. What’s more, if you don’t want to work with command line tools, do a ‘yum install yumex’. Yumex works like a gem. Search for a software to install, add it to queue and process it! The interface is pretty sweet too.

Fedora Core 5 -vs- Windows XP

It took me a year but I’ve finally moved my stuff over to Linux. I had to. I’m supposed to be a geek.

It’s like moving into a new city. You don’t know where to get the groceries, how to get around. Stuff that sounds trivial where you’ve spent your whole life. Despite the problems, i’ve managed to set up shop in linux. I’ve got almost everything ready. Graphics editting, lisp programming, internet.

Moving away from internet explorer to firefox was easy. There are problems in linux but I think they’re manageable.