Laurent Cheylus

Software engineer specialized in Cybersecurity

Linux OpenBSD FreeBSD - FOSS Contributor
Lyon (France) addict
Messages in French đŸ‡«đŸ‡· and English 🇬🇧

Laurent Cheyluslcheylus@bsd.network
2025-05-02

Owen Le Blanc: creator of the first Linux distribution "MCC Interim Linux", released publicly in early 1992 - Article by LWN #Linux lwn.net/Articles/1017846/

Laurent Cheylus boosted:
Julia Evansb0rk@jvns.ca
2025-05-02

stdin, stdout, and stderr

Panel 1: all terminal programs have 1 input and 2 outputs 

they're numbered: stdin is "0", stdout is "1", stderr is "2". 


(the numbers are called "file descriptors")

panel 2: you can set them to be any file you want

person: “I don't want to display the output in my terminal emulator, I want to write it to a file”
person: “I'll have the proram read input from a file instead of typing it in"

panel 3: 3 things you can set the inputs/outputs to

1. the TTY (so output is displayed in your terminal emulator)
2. a file
3. a pipe (to write output to the input of another program)

panel 4: your shell is in charge of setting up stdin/stdout/stderr

person: “python3 script.py > out.txt”

shell: “ok, I'll set stdout to out.txt for that program”


more about the syntax on page 15

panel 5: on 2>&1

2>&1 redirects stderr to stdout

you could also do 1>&2 but I've never used this N>&M syntax for anything other redirecting stderr to stdout

panel 6: gotcha: programs often buffer stdout but not stderr

when a program writes text to stdout, it'll often

1. check if stdout is a TTY (using the isatty function)
2. if not, "buffer" the writes until there's 1KB of data to write, for performance reasons

(this is the default in libc)
Laurent Cheylus boosted:
2025-05-02

#vendredilecture Scrum, un outil convivial pour une agilité radicale.
Je le relis ou disons plutÎt que je le parcours pour préparer la master class sur Scrum et l'agilité qu'on va enregistrer la semaine prochaine avec @pablopernot
#scrum #agile

La couverture de Scrum Ă©dition 6 avec un dessin d'Étienne Appert montrant une Ă©quipe de 6 personnes (paritĂ©) mettant Ă  jour ensemble des post-it avec un genou Ă  terrre
Laurent Cheylus boosted:
Bryan Steele :flan_beard:brynet@bsd.network
2025-05-02

Looks like mpi@ has been roleplaying as Doomguy, R.I.P and tearing the reaper process out of the #OpenBSD kernel. :flan_hacker:​ :flan_cleaver:​ :flan_evil:​

marc.info/?l=openbsd-tech&m=17

If people are interested, Martin is looking for test reports.

I'd appreciate tests reports on many different setups as well as other architectures.

Laurent Cheylus boosted:
Bryan Steele :flan_beard:brynet@bsd.network
2025-05-02

David Gwynne (dlg@) has imported a new daemon to #OpenBSD -current, not yet linked to the build.

lldpd(8), a new LLDP (Link Layer Discovery Protocol) agent daemon.

This daemon uses the newly added AF_FRAME socket protocol type.

dlg@ modified src/usr.sbin/lldpd/*: lldpd(8): a daemon that acts as an LLDP agent on Ethernet interfaces.

lldpd uses the recently added AF_FRAME Ethernet sockets to listen for LLDP packets on all Ethernet interfaces in the system, and stores them so a lldp(8) client connecting to the control socket can fetch and display the packets.

AF_FRAME means we can avoid BPF for receiving LLDP packets, which has a couple of benefits.

firstly, BPF needs to look at all packets entering an interface so it can filter for the ones you're interested in, which is annoying for low packet/data rate protocols like LLDP. AF_FRAME is handled late in ether_input, and only after other protocols (like ip) are handled, so it's lower overhad compared to BPF listeners.

secondly, attaching a BPF filter to new interfaces relies on having access to and the privileges to open /dev/bpf, while AF_FRAME provides a wildcard listener that is able to receive LLDP from all interfaces on a single socket, like how binding to on 0.0.0.0 with an AF_INET socket let's you receive packets for all the IPs on your system from a single socket. lldp can create and configure this socket when it starts up just use it from then on. this means lldpd is simpler and needs fewer privileges to operate than if it went the BPF route.

at the moment lldpd only handles LLDP packet reception on all interfaces, you can't disable reception on interfaces yet. it also doesn't transmit LLDP packets (yet).

there is no intention of implementing any protocol other than LLDP in this daemon either.

ok djm@ deraadt@ general enthusiasm from many

Laurent Cheyluslcheylus@bsd.network
2025-05-02

Moins connu que Tor ou les VPN, un rĂ©seau capable de brouiller les pistes au point de rendre toute surveillance caduqe : c’est la promesse du Mixnet. #Privacy clubic.com/actualite-553113-to

Laurent Cheylus boosted:
2025-05-02

Ah bah super le principe des péages à flux libre...
Tu veux stalker quelqu'un ? Tu va sur www.sanef.com, tu rentre le numéro de la plaque d'immatriculation, et tu vois si elle a été sur une zone à péage, avec la date.
T'as pas le détails des trajets (sauf si tu créé un compte...), mais rien qu'avec la date et le prix, tu peux deviner des choses...

Comment des gens peuvent se dire que c'est une bonne idée de faire ça ??

Laurent Cheylus boosted:
2025-05-02

Call for testing and comment: Make the installer prefer >1G disks undeadly.org/cgi?action=articl

Laurent Cheylus boosted:
2025-05-02
Laurent Cheylus boosted:
Combat Unicornkurtm@bsd.network
2025-05-02

There is no official OpenBSD Handbook.

The site claiming to be so is not from the project, and on top of just copy and pasting a lot of FAQ content (at one point) without credit, it has lots of things that are incorrect.

The amount of times I see "Well, that's what the handbook says" on reddit. :flan_rage:​

#OpenBSD

Laurent Cheyluslcheylus@bsd.network
2025-05-02

2024 Zero-Day Exploitation Analysis by Google Threat Intelligence Group (GTIG): 75 0Day Vulnerabilities exploited in the Wild in 2024, nearly 53% of Total attributed to traditional Espionage Actors #ThreatIntelligence #CyberSecurity cloud.google.com/blog/topics/t

Diagram for 2024 attributed Zero-Day Exploitation by Google Threat Intelligence Group
Laurent Cheylus boosted:
2025-05-01

#EU_OS looks out for potential early adopters in the public sector to inform the design of the proof of concept.

Many current Linux on the Desktop deployments are in the education sector: schools and universities.

Dear @primtux or any other education Linux project, would you be interested to join the first developer sprint in person in Paris or online?

Event: hackdays.numerique.gouv.fr/

Planning: gitlab.com/eu-os/eu-os.gitlab.

@bluehats @codegouvfr @blagarrigue
@ThierryM
#plasma #gcompris #endof10

Laurent Cheyluslcheylus@bsd.network
2025-05-01

World's first successful Lightning triggering and guiding using a Drone by harnessing Electric Field Fluctuations - Demonstration by NTT in Japan #Research group.ntt/en/newsrelease/2025/

Diagram of a demonstration for lightning triggering and guiding using a drone
Laurent Cheylus boosted:
Guillaume Gomezimperio@toot.cat
2025-05-01

I'm wrapping the next Rust sysinfo crate release, however I have one last issue I can't figure out how to fix.

On Windows, I can't figure out how to retrieve (user but not user's) groups.

I originally tried with NetGroupEnum and just updated to use NetQueryDisplayInformation as it was supposed to be faster.

If there is anyone who knows how to fix this bug, it'd be super appreciated!

You can test it by running cargo run --example simple and then type the "groups" command.

Code: github.com/GuillaumeGomez/sysi

#rust #rustlang

Laurent Cheylus boosted:
2025-05-01

Le programme de l'édition 2025 des Journées du Logiciel Libre est en ligne : pretalx.jdll.org/jdll2025/sche. Voilà de quoi remplir votre week-end du 24-25 mai, dans tout juste un mois !

Pour rappel, notre financement participatif est toujours en cours : helloasso.com/associations/jou

#JdLL #JdLL2025 #Event #Lyon #Aura #LogicielLibre

Capture d'écran illisible du programme des JdLL 2025
Laurent Cheylus boosted:
2025-05-01

Derniers jours pour le financement participatif des JdLL 2025 !

Sur place, il ne sera pas possible d'acheter ces t-shirts et hoodies


Montrez-vous avec style aux repas de famille avec le t-shirt JdLL 😎

C'est par ici jusqu'au dimanche 4 mai : helloasso.com/associations/jou

#JdLL2025 #JdLL #FinancementParticipatif #HelloAsso #Tshirts #Hoodies

Laurent Cheylus boosted:
joshua :veri:josh@masto.byrd.ws
2025-05-01

too many things are dependent on github

Laurent Cheylus boosted:
2025-05-01

Lots of sensible advice from @Marcus in this blogpost, on giving conference talks.

marcusnoble.co.uk/2025-04-30-m

Laurent Cheyluslcheylus@bsd.network
2025-05-01

Japan’s YKK, the world’s largest Zipper Manufacturer, has announced a prototype self-propelled Zipper with a built-in Motor and gear Mechanism it can use to zip itself up at the Push of a Button on a wired Remote. theverge.com/news/656535/ykk-s

Laurent Cheylus boosted:
OpenBSD Journal RSS đŸ€–openbsdjournal
2025-05-01

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