Some days ago the DNS server of my dormitory stopped working, so I (we, me and all my colleagues) lost most of the network functionality. As the DNS port is blocked by the dormitory firewall, I could not rely on external servers to resolve names, so… ? Fortunately, I had already established an SSH tunnel towards the outside world, so I wondered if I could use it to solve my problem. If only I could re-route the local DNS requests over the TCP tunnel…
Well, I was not able to force my system to resolve names over TCP, so I needed a “UDP to TCP, and back” translation mechanism. Briefly, udp2tcp was born!
For a couple of years I used Vmware as virtualization solution, because the alternatives weren’t at its level. I used to run Vmware to emulate a WinXP-Pro guest, with IIS, to write an ASP project for a course. Thanks god, the teacher changed his mind and let some of us code in PHP as well. Anyway, recently Vmware went crazy. Whenever I open it, it just disables my Shift and Control keys: only restarting X solves to problem.
It’s released under the GPL. And this is a very good thing.
It does not mess up with my keyboard. Yay!
Bad news:
I have to use the binary image of the program, because the GPL’d version has no USB support (and I need it for another course).
Requires the QT libraries to run. Yuck! As I am a Gnome user, I try to avoid QTs as much as possible. Well, nevermind, I’ve packaged them some time ago (when I used the GUI of wpa_supplicant, but this is another story), so I do not have to compile them.
The last issue drove me crazy. To set up networking in Virtualbox you have three choices (well, actually four, but I do not consider “cable unplugged” a choice )
You can use a “fake” NAT, but it makes very painful the access to guest resources. You have to manually map your resources onto local ports: this is secure (well… not very secure, actually, as the socket binds to the INADDR_ANY address, and not on the loopback device), but not as friendly as the Vmware solution (that is, NAT the guests and give to the host OS a virtual network interface on the guests LAN).
You can use a network bridge. But this is bad, as it exposes your guests to your LAN. The problem could be solved using iptables, but, in my case, it wouldn’t help very much, as I cannot have more than one MAC address per computer (dormitory restrictions).
You can configure a local network between guests with no host connectivity. Not really a solution.
I looked for informations on the Net. No solution. So I decided to write a shell script on my own.
Why not? It combines my Bash and networking skills, and I like writing little tools, so…
It’s written with the Gentoo subsystem in mind, but it can be ported to other distros with little pain. It’s very easy to set up: edit the beginning of the script, substituting dark with your username and eth1 with the name of the physical interface that you use to connect to the world. Basically, it does the following:
Loads/unloads the Virtualbox kernel module
Starts/stops the Virtualbox network interface
Associates the Virtualbox network interface with the user that runs the Virtualbox guest
Enables/disables IP packets forwarding in the whole system
Starts/stops the iptables userspace daemon
Adds a iptable rule to allow NAT
And that’s it
UPDATE: I’ve edited and uploaded again the script to resolve the issue at comment #1. If /sbin/functions.sh is missing, wrappers functions are defined to handle the console output.
We already knew about the volcanic minds of the guys working at Google HQ, but their latest inventions are really awesome. I’m pleased to introduce you to their latest ideas: Google TiSP and Gmail Paper. Details following.
Google TiSP is a (mostly) free wireless broadband service brought to you right by Google, using a not conventional medium: the sewer system. As carefully explained on their website, the subscribers will receive at home a small installation kit, including an optic fiber rope, a pair of gloves, a wireless router and an installation CD. The end user should only drop one end of the fiber into the water and flush the toilet and the so-called Plumbing Hardware Dispatchers (PHDs) will take care, in the sewers, to connect it to the global networking system. Google assures that the free version of this technology permits a 8 Mbps speed in downstream and 2 Mbps in upstream. If you’ve still some questions unsolved, give a look to the FAQ or to their official press release.
Gmail paper, instead, is a service related to the widely known Google Mail offer. The new invention is that you can ask Google to print as many of your e-mail as you like and have them delivered for free at home, including attachments (if they can be printed, of course: you won’t receive a copy of audio files as they state on the linked page, but images will be printed on a high-quality, glossy photo paper). “Gmail Paper is made out of 96% post-consumer organic soybean sputum”, they say, so it won’t hurt the environment.
As a side note: have a nice day, out there, today ;).
From now on, every teacher (or in general every programmer) using a Linked List must remember that he’s talking about a patented idea. If you do not believe to me, check out for yourself here or here.
Finally the package netscape-flash, version 9.0.31.0, is stable on x86 and amd64!
I have used the unstable version for 2 weeks and it worked fine for me: finally I watched to the Flash videos without that annoying lag between audio and video stream. The big drawback is that, sometimes, when closing webpages with embedded Flash objects, mozilla-firefox crashes.
While browsing YouTube website, I accidentally found this video, presenting the prototype of a new 3D desktop manager called BumpTop.
The most interesting feature of BumpTop is the usage of real world physics to rule the movement of the icons; like paper sheets or CD-DVD boxes, you can move or even throw them around, just like you would do on your desk. The usefulness of this approach? None, IMO. It’s just eye-candy, a waste of useful resources and CPU power.
It seems that the very popular 1-click-hosting website Rapidshare raised the interest of the GEMA (Gesellschaft für musikalische Aufführungs- und mechanische Vervielfältigungsrechte or, translated in English, Society for musical performing and mechanical reproduction rights).
The Heise Online website reports that GEMA obtained an injuction against Rapidshare for having illegally allowed its users to upload content protected by copyright. The owners of the website defend themselves saying that the users upload files under their own responsability, so Rapidshare, under a legal point of view, is absolutely not guilty.
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It combines my Bash and networking skills, and I like writing little tools, so… 
