Piero V.

Back to Rust again

In 2010 I tried to program a video game with a friend for the first time. And it was our first time with C++, too. Of course, it was C++2003 since C++11 was the new-not-yet-stable thing.

I must say that our approach was quite naive. For example, we thought we would always play the game on a LAN. Thus, we never worried about lag compensation.

Now, a few years have passed, and I have learned a thing or two, even though I still have to finish a game project.

So, at the beginning of this year, this friend pushed me to learn Rust, and I decided to learn it through game development again.

At a certain point, I decided to use a physics engine, and I found Rapier. I was especially interested in its determinism to finally implement a lag compensation mechanism. But I did not understand how to use it correctly. Only recently, I understood it favors an approach similar to functional programming, whereas I was trying an OOP-like approach. This also led to fights with the borrow checker. So, because of these problems and my usual decrease in interest and focus, I left yet another project incomplete. … [Leggi il resto]

Another rant on emails

A pair of weeks ago, some people asked me for help because their Outlook was not working anymore. It complained that its data file had reached the maximum size.

Being a Linux user, I have never had Outlook on my machines.

I used it only at my previous job, with an exchange server. I must admit it used to work fine. It even has some appreciable features, such as the company directory, shared calendars that work immediately, etc.

So, when people ask me if I can help them with their Outlook problems, I try to answer as a courtesy. Usually, they are easy problems, and I solve them by searching for their error messages in English and translating the solution into Italian.

One of the suggested solutions for the problem was to empty the bin. But it contained almost one million emails 😨️. So, I went to the webmail and found that the webmail also has the same amount of emails to delete.

The web client also says that emails are automatically deleted after 90 days, but it contained emails from more than two years ago.

It also has a button to empty the folder… but I think it communicates to the backend through IMAP itself, and of course, it went on timeout 😄️. … [Leggi il resto]

Debian on an encrypted microSD on a Surface Pro 2017

Wow, I have not needed to write a guide about installing a Linux system for years (well, these are my notes rather than a complete guide).

Partly because I found it quite easy in the latest… 5 years? Partly because I avoid reinstalling my systems unless strictly needed.

This time is different: I am targeting a peculiar device (a Surface Pro 2017) with a microSD (I am too lazy to repartition its SSD) and full disk encryption (including /boot).

But I am happy because I have learned a lot! For example, if you choose the expert installation for Debian, you can disable the source repositories immediately!

Big caveat: my initial plan was to install GRUB on the microSD, but it did not work. If I understood correctly, the Surface cannot boot from SDs. So, I used the ESP of the SSD. If you wanted a completely autonomous system on a microSD that disappears as soon as you remove it, I fear you cannot get one.

Preparing the install drive

After I discovered Rufus, I have always used it to prepare installation drives on Windows.

But Debian ISOs have a feature I really appreciate: in UEFI mode, you can just extract the image to a FAT32 partition. The advantages are that you do not need Windows, and you do not have to format the drive, you do not lose any existing data. And, on top of that, secure boot worked at the first try (with Microsoft & 3rd party CAs, but I do not remember if it is the default). I have tried with other distributions, but none worked in the same way. … [Leggi il resto]

That tiny little option

Almost one year ago, I switched to a Cudy WR2100.

It has worked very well in these months. I installed it, then forgot about it, but it kept doing its job.

A few months ago, we bought a cheap TV, which happened to be an entry-level Android TV, too. I tried to set it up to connect to WiFi, but it did not work. Initially, I blamed the TV, but we did not buy it for its “smart” functionalities, so we just used it as a plain-old TV for some time.

But after a while, I wanted to use my old Oneplus One as a test device with Android 9, and it could not connect, too!

I solved the issue on the phone by updating it to an Android 10 ROM (and I had to find another way to deal with the original problems that needed Android 9 in another way 😮‍💨️).

Therefore, I initially thought Pie was the problem and that Android 10 fixed some bugs. But good luck finding information about an issue like this!

Eventually, a few days ago, I thought of carefully checking OpenWRT settings. I found that “Disassociate On Low Acknowledgement”, which allows the access point to disconnect stations based on low ACK conditions, was enabled. It can be set on a network basis, so it should be turned off separately for the 2,4GHz and the 5GHz, and it is the last item in the latest tab (advanced settings).

That fixed my problems. It is the first time I have found an option that could be a wrong default on OpenWRT in all these years. Or is it a problem with the MediaTek drivers? I am not sure, to be honest.

I must say that some functionalities like YouTube works pretty well and are convenient. I would have loved to use the built-in Chromecast, but I had continuous disconnections. So, maybe the fault must be shared between the TV and the router, after all 😅️.

Zbar, GTK and Python 3

Last week, we had Hackweek at Tor. Instead of doing what we usually do, we worked on small Tor-related projects for 5 days. I chose to work with intrigeri and boyska from Tails to help them improving the pluggable transports on Tails.

There are several ways to get Tor bridges. One is requesting them to BridgeDB through email. The answer contains the bridge lines both as text and in a QR code. So, the first objective of our Hackweek team was to create a proof-of-concept to load these QR codes through a webcam.

Tails’s connection wizard is written in Python. A trivial approach is capturing frames from the webcam with OpenCV, then decoding them with pyzbar. This would have worked, but Tails is a live system, and an OpenCV installation requires a lot of space.

I soon discovered that OpenCV is the de facto way to deal with webcams in Python. I have tried some other alternatives, but they did not work. I have also tried to use a low-level approach based on the V4L2 API. But dealing with the conversion of color spaces and creating a generally reliable solution is burdensome. … [Leggi il resto]