Le blog de Tester

When a man page lies

Tester — Fri, 24 Jul 2009 18:09:29 +0000

The part of the socket(7) man page about setsockopt(.., SOL_SOCKET, SO_PRIORITY…) says:

« For ip(7), this also sets the IP type-of- service (TOS) field for outgoing packets. »

I wanted to know how exactly it mapped the socket priority to the ToS field, so I looked in the kernel code for a while, and it turns out that in recent Linux 2.6 kernel, this is a lie. The ToS field is never set when the application selects the socket priority, only the internal priority of the packet is set. That said, the reverse is true, setting setsockopt(.., IPPROTO_IP, IP_TOS…) sets both the ToS header field and the internal priority of the packet.

So the question here is: Who is wrong, is the kernel buggy? Or is the man page incorrect?

Also, dear lazyweb, is there any support for applications to set the DiffServ field? Or are they only settable through iptables?

foss.in

Tester — Fri, 28 Nov 2008 12:14:00 +0000

I’m in Bangalore for foss.in. First, the country is awesome, the Indian food is amazing, etc, etc. The weather is also pretty nice this time of year, not too warm, not too cold, just right. Although it has been a bit rainy in the last three days.

But its not only the country that is nice, it is also an awesome conference, the organizers are really doing a great job. The venue is nice, the speakers are really well treated, etc. But more importantly, the level of the conference is also quite impressive. It is a great place to meet lots of good developers that we rarely meet in the « western » conferences. Free Software is really alive in India and it is great to meet the people here. After my Farsight 2 talk (slides), there were some really good questions, from people who had actually tried to use it. It’s the fourth (and last) time that I give this talk in front of different audiences, and I really got the best questions and the best interaction. The organizers wanted to make it into a truly developer oriented conference and they’ve really succeeded.

fsck failure drops me into a shell

Tester — Thu, 18 Sep 2008 19:06:41 +0000

One of my non-geeky friends is currently trying Linux on his laptop. For some reason, he stopped it incorrectly and on the next reboot a fsck was forced and the fsck failed… he gets this:

*** An error occurred during the file system check. *** Dropping you to a shell; the system will reboot *** when you leave the shell. Give root password for maintenance (or type Control-D to continue):

Obviously, at this point, he had no idea what to do… He couldn’t boot into his system and he had no idea how to fix it.

THIS IS REALLY REALLY STUPID AND BAD!

And it seems all distributions are doing it, including the supposedly user friendly ones like Fedora and Ubuntu. All non-geeks will be completely lost at this point…

What should be done is: « Repairing your file system may cause errors!!! Do you want to: [F]orce Repair, get to a [S]hell or [R]eboot? » .. ideally in a nice curses front-end. And in the force repair case, just run « fsck -y ».

Monts Cascade et Porter

Tester — Mon, 01 Sep 2008 23:02:14 +0000

Hier, je suis allé monter deux sommets des Adirondacks avec Mark et Amélie. Je suis donc rendu a 4 des 46 sommets des Adirondacks (avec Marcy et Giant). J’ai fait ce beau panorama 360, mais je ne trouve malheureusement pas de beau script simple pour l’afficher de manière continue (à la manière de Google Maps). J’ai trouvé celui-ci qui me semble pas mal, mais il n’est pas 360.. Si vous en connaissez, passez le mot.

Je me suis aussi amusé avec le GPS de mon N810 à enregistrer le chemin que nous avons emprunté et à géotagger les photos.. La carte et l’ensemble des photos suivent…

GnomeICU at the forefront of tabs

Tester — Sat, 12 Jul 2008 15:36:11 +0000

There seems to be this new fad at adding tabs, but GnomeICU has had them for years, since 2002. You guys are like sooo late.

Une personne, 1.75 vote?

Tester — Wed, 28 May 2008 17:35:52 +0000

Quand j’étais à la petite école, j’ai appris que dans une démocratie, on avait une personne, un vote. Mais ce n’est plus le cas au Québec. Le vote d’un électeur de la circonscription de Matane vaut 1.75 fois celui d’un électeur de Vaudreuil[1]. Bien sur, les gens de la Gaspésie veulent garder leur privilège, mais qui défend les habitant lésés de la région montréalaise. Je trouve inquiétant de ne voir aucun politicien, même pas notre maire, défendre nos intérêts.

[1] Deux comtés choisis au hasard, Vaudreuil et Matane

Summer of Code

Tester — Mon, 31 Mar 2008 16:21:31 +0000

Students! There are only a few days left (until Monday) for you to submit your Google summer of code applications. This year, I’m hoping to mentor students working on Farsight 2 or on integrating Farsight in various applications. The most interesting project I’m proposing this year is adding plugins for the various non-free protocols to Farsight (see details), MSN is particularly easy since most of the reverse-engineering has already been done, its just a matter of coding it. GStreamer has a page on how to write a good application (hint hint, Farsight’s project are part of GStreamer this year!). I’m also a mentor on Gnome & Gentoo in case anything interesting is proposed there, so if you have good idea, go submit them now, time is running out!
Update: Google has extended the application period for one more week, so there’s still time… And we already have a good applicant for MSN, but please do apply for Yahoo, AIM, ICQ, etc!

Une journée, deux continents, cinq pays

Tester — Mon, 03 Mar 2008 18:27:59 +0000

Hier, je me suis levé à Paris, j’ai déjeuné à Bruxelles, j’ai diné à Londres, soupé à Chicago et je me suis couché à Montréal.

Farsight at fosdem

Tester — Sun, 24 Feb 2008 13:37:21 +0000

Its my first time at fosdem, and I’m really impressed by the sheer size of the conference, every European Free Software developer seems to be here (its really nice to see old friends and meet new people, there just seems to never be enough time to see them all!). Also too many talks at the same time, too many interesting things to see! I also got to give my Farsight 2 talk (slides here) and the talking part when pretty well I think, but the demo sucked. We never got the network to work properly (not trying it more than 5 minutes before the talk ended up not being a good idea). So I had to do it locally with one camera and 2 test sources, its sad, considering how well it worked at linux.conf.au (see the LCA video to see it work). Also considering how many bugs I fixed since LCA and that I even got h.264 to work.

Melbourne

Tester — Sun, 27 Jan 2008 23:38:47 +0000

Hier, je suis arrivé a Melbourne après presque 20h de vol. Nous avons d’abord fait un arret a L.A. ou nous sommes allés sur Hollywoord Blvd faire un petit tour, histoire de prendre un burger et une petite bière. Le vol fut beaucoup moins pénible que je ne l’avais imaginé, en fait ce n’est pas beaucoup plus pénible que d’aller en Europe. Le décalage horaire, c’est « seulement » 8h, donc une seule de plus que Helsinki, et l’ajustement s’est très bien passé pour le moment. Plus de nouvelles suivront…