The Internet

This was on my home page a LOT of time ago, found it again today among old stuff

Q: But what *IS* the internet?

A: It’s the largest equivalence class in the reflexive transitive symmetric closure of the relationship “can be reached by an IP packet from”.
–Seth Breidbart

[From Craig Simon on the IETF mailing list which I followed around 2000 A.D., where he stated that he did read it on “someone sig line”.]

They were funny times.
[and then again, this post was originally written on Jan 22nd, 2009 :D]

No news is good news :)

Ok, it’s been five years from the last post.
Five. Years.
It’s not I gave up having fun building/breaking stuff, but there’s not much of what I’ve been doing lately that may interest my geek friends. :\
Changed city, changed employer (still red though), always in the quest to do something fun and interesting.

Anyway, in my current intentions this site/blog is not going away anytime soon: even if we live in the most social-rich-media society, I feel that it still makes sense having something that just works — with no ties to centralized points of failure (aws, facebook, cloudflare, …) — and where nobody can censor me.

Maybe it will take five more years to make something appear here, but this little corner will stay.

Happy hacking!

Some small changes

Ok, this post may come as a surprise to my 4 readers (two, excluding people I meet every day) BUT I finally took some time to apply some changes:

  • site look has been changed. I still want to replace the standard theme pictures with my own, but this wil take a little longer
  • the feed address has been converted to the “new” feedburner URL. Old link may still work, I don’t know how long and if it will still be updated. New link is or
  • did you notice that the link above is to https? most of the site should now work seamlessly over both http and https. I plan to make it accessible over https only in the near future, even if some resources may remain over plain https.

that’s all, see you in a couple of years. :)

TODO: turn IPv6 on. I’m not far from that too.

A tiny hack

(A post every 10 months. I hope that does not annoy you :) It will not take long to read, anyway. )

Transmission is a great BitTorrent client. It is full of features (look at the site!), including bandwidth control, and runs on every platform (Linux and Mac :P).
You can choose global upload and download speeds, or shape single torrents among those you are working with.
At home I have a 10mbit connection to the Internet so I rarely limit the torrents, but most of the time when I do it is to reserve a small quantity of bandwidth for Internet browsing while I wait, or to play online.

Transmission is a bit rigid regarding the possible speeds: the only possible values (for both upload and download) expressed in kilobytes/sec are 5, 10, 20, 30, 40, 50, 75, 100, 150, 200, 250, 500, 750, 1000, 1500, 2000. My home network chokes around 600. I could set for 500k, but where’s the fun?


  • head to and read thoroughly [the part specifying that you need to have XCode installed, for example]
  • learn that “Building the project on Mac requires the source to be retrieved from SVN. Pre-packaged source code will not compile.
  • download the SVN code (uhm, yes. I also have pkgsrc installed):
    svn co svn:// Transmission
    in my case the version number was 2.11 1133-something.
  • run a “dry” compile run — this will guarantee that the code is not broken before you start tinkering with it or that you have some local issue (my first time doing actually something with XCode. Easier than I thought, the source has an XCode project file)
  • find the relevant source files (grep was my friend). In the end I only modified Controller.m and TorrentTableView.m: find the line
    const NSInteger speedLimitActionValue[] = { 5, 10, 20, 30, 40, 50, 75,
    100, 150, 200, 250, 500, 750, 1000, 1500, 2000, -1 };

    and modify it to match the speeds you want to be able to use. You can add or remove values as you like as long as the syntax is right.
  • compile it again and run it. :)

If I were a programmer, I’d have implemented something that would allow the user to choose the speed as he liked — but this fits my needs.

Northwest Flight 253 and the “security” of it all

By now I think everybody has heard of the unsuccessful [terrorist?] attack to Northwestern Flight 253, where Umar Farouk Abdul Mutallab tried to mix bomb components about one hour before the plane landed.

We’re so used to the restrictions applied to passengers of flights, that we almost think of them as routine, while we should always think about the effectiveness of "security" measures as they are applied. The most lacking resource being often common sense.

In this case, we can already read of the next restrictive measures, on the NHS site:

The Department of Homeland Security immediately put additional screening measures into place […]

Passengers flying from international locations to U.S. destinations may notice additional security measures in place. These measures are designed to be unpredictable, so passengers should not expect to see the same thing everywhere.

So, we’ll get more restrictions, but not the same everywhere. (WTF #1)

Next, let’s see what the TSA has in mind for us:

Among other things, during the final hour of flight customers must remain seated, will not be allowed to access carry-on baggage, or have personal belongings or other items on their laps[…]

as someone else said, I’m glad that the "terrorist" didn’t try to blow himself up three or more hours before. Now, I will not be allowed to take a book (or put it away) during just the last hour of the flight, but this will surely scare all those terrorists that can act and think only during that last flight hour. (WTF #2)

I still consider myself lucky, though, because:

Effective today, the TSA has informed Northwest that travelers are not allowed to transport any liquids, gels, lotions or similar items in their carry-on luggage. This includes items such as beverages, hairspray, toothpaste and shampoo. These types of items can only be carried in checked luggage.

In the end, I do not agree with those who say that as the attack was not successful, no additional security measures would be needed. I still strongly believe that in this cases early intelligence

Mutallab’s name had surfaced earlier on at least one U.S. intelligence database, but not to the extent that he was placed on a watch list or a no-fly list.

is much more useful than a guy asking me to leave my water bottle at the security check.

In the meanwhile, it leaves me surprised that the bomber left from an airport that the TSA confirmed compliant just a month ago. Again: either the airport security failed, or the security procedures and requirements are just wrong.

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