pudc - A PID 1 process that barks to the internet by mssola

Description

As a fun exercise in order to dig deeper into the Linux kernel, its interfaces, the RISC-V architecture, and all the dragons in between; I'm building a blog site cooked like this:

• The backend is written in a mixture of C and RISC-V assembly.
• The backend is actually PID1 (for real, not within a container).
• We poll and parse incoming HTTP requests ourselves.
• The frontend is a mere HTML page with htmx.

The project is meant to be Linux-specific, so I'm going to use io_uring, pidfs, namespaces, and Linux-specific features in order to drive all of this.

I'm open for suggestions and so on, but this is meant to be a solo project, as this is more of a learning exercise for me than anything else.

Goals

• Have a better understanding of different Linux features from user space down to the kernel internals.
• Most importantly: have fun.

Resources

• https://github.com/mssola/pudc

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HTTP API for nftables by crameleon

Background

The idea originated in https://progress.opensuse.org/issues/164060 and is about building RESTful API which translates authorized HTTP requests to operations in nftables, possibly utilizing libnftables-json(5).

Originally, I started developing such an interface in Go, utilizing https://github.com/google/nftables. The conversion of string networks to nftables set elements was problematic (unfortunately no record of details), and I started a second attempt in Python, which made interaction much simpler thanks to native nftables Python bindings.

Goals

1. Find and track the issue with google/nftables
2. Revisit and polish the Go or Python code (prefer Go, but possibly depends on implementing missing functionality), primarily the server component
3. Finish functionality to interact with nftables sets (retrieving and updating elements), which are of interest for the originating issue
4. Align test suite
5. Packaging

Resources

• https://git.netfilter.org/nftables/tree/py/src/nftables.py
• https://git.com.de/Georg/nftables-http-api (to be moved to GitHub)
• https://build.opensuse.org/package/show/home:crameleon:containers/pytest-nftables-container

Results

• Started new https://github.com/tacerus/nftables-http-api.
• First Go nftables issue was related to set elements needing to be added with different start and end addresses - coincidentally, this was recently discovered by someone else, who added a useful helper function for this: https://github.com/google/nftables/pull/342.
• Further improvements submitted: https://github.com/google/nftables/pull/347.

Side results

Upon starting to unify the structure and implementing more functionality, missing JSON output support was noticed for some subcommands in libnftables. Submitted patches here as well:

• https://lore.kernel.org/netfilter-devel/20251203131736.4036382-2-georg@syscid.com/T/#u

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Provide personal account sign-in for Himmelblau (Azure Entra Id) by dmulder

Description

Himmelblau currently does not support personal account sign-in, but only sign-in for business/school accounts. Adding personal account sign-in would broaden the userbase, and potentially attract more users to Linux from Windows (since they could easily migrate their existing Windows account, etc).

Goals

Implement personal account sign-in for libhimmelblau.

Resources

gitlab.com/samba-team/libhimmelblau

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Add a machine-readable output to dmidecode by jdelvare

Description

There have been repeated requests for a machine-friendly dmidecode output over the last decade. During Hack Week 19, 5 years ago, I prepared the code to support alternative output formats, but didn't have the time to go further. Last year, Jiri Hnidek from Red Hat Linux posted a proof-of-concept implementation to add JSON output support. This is a fairly large pull request which needs to be carefully reviewed and tested.

Goals

Review Jiri's work and provide constructive feedback. Merge the code if acceptable. Evaluate the costs and benefits of using a library such as json-c.

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Smart lighting with Pico 2 by jmodak

Description

I am trying to create a smart-lighting project with a Raspberry Pi Pico that reacts to a movie's visuals and audio that involves combining two distinct functions: ambient screen lighting(visual response) and sound-reactive lighting(audio response)

Goals

• Visuals: Capturing the screen's colour requires an external device to analyse screen content and send colour data to the MCU via serial communication.
• Audio: A sound sensor module connected directly to the Pico that can detect sound volume.
• Pico 2W: The MCU receives data fro, both inputs and controls an LED strip.

Resources

• Raspberry Pi Pico 2 W
• RGB LED strip
• Sound detecting sensor
• Power supply
• breadboard and wires

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x64id: An x86/x64 instruction disassembler by m.crivellari

Description

This is an old side project. An x86/x64 machine code decoder. It is useful to get instructions' length and identify each of its fields.

Example:

C7 85 68 FF FF FF 00 00 00 00

This is the instruction:

MOV DWORD PTR SS:[LOCAL.38],0

What follows are some of the information collected by the disassembler, based on the specific instruction:

RAW bytes (hex): C7 85 68 FF FF FF 00 00 00 00
Instr. length: 10
Print instruction fields:
        Located Prefixes 0:

        OP: 0xC7
        mod_reg_rm: 0x85
        disp (4): 0xFFFFFF68
        Iimm: 0x0

Lacks the mnemonic representation: from the previous machine code is not able to produce the "MOV..." instruction, for example.

Goals

The goal is almost easy: partially implement the mnemonic representation. I have already started during the weekend, likely tomorrow I will push the branch!

Resources

• The project: https://github.com/DispatchCode/x64-Instruction-Decoder/
• This is useful to avoid gdb and objdump in local: https://defuse.ca/online-x86-assembler.htm
• Another interesting resource is https://godbolt.org/

Progress

• An initial implementation can be found at: https://github.com/DispatchCode/x64-Instruction-Decoder/tree/mnemonic-support It is described under the "Mnemonic translation" in the README file!

Let's consider this example:

[...other bytes...] 43 89 44 B5 00 01 00 [...other bytes...]

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pudc - A PID 1 process that barks to the internet by mssola

Description

As a fun exercise in order to dig deeper into the Linux kernel, its interfaces, the RISC-V architecture, and all the dragons in between; I'm building a blog site cooked like this:

• The backend is written in a mixture of C and RISC-V assembly.
• The backend is actually PID1 (for real, not within a container).
• We poll and parse incoming HTTP requests ourselves.
• The frontend is a mere HTML page with htmx.

The project is meant to be Linux-specific, so I'm going to use io_uring, pidfs, namespaces, and Linux-specific features in order to drive all of this.

I'm open for suggestions and so on, but this is meant to be a solo project, as this is more of a learning exercise for me than anything else.

Goals

• Have a better understanding of different Linux features from user space down to the kernel internals.
• Most importantly: have fun.

Resources

• https://github.com/mssola/pudc

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Port OTPClient to GTK >= 4.18 by pstivanin

Project Description

OTPClient is currently using GTK3 and cannot easily be ported to GTK4. Since GTK4 came out, there have been quite some big changes. Also, there are now some new deprecation that will take effect with GTK5 (and are active starting from 4.10 as warnings), so I need to think ahead and port OTPClient without using any of those deprecated features.

Goal for this Hackweek

• fix the last 3 opened issues (https://github.com/paolostivanin/OTPClient/issues/402, https://github.com/paolostivanin/OTPClient/issues/404, https://github.com/paolostivanin/OTPClient/issues/406) and release a new version
• continue the rewrite from where we left last year
• if possible, finally close this 6 years old issue: https://github.com/paolostivanin/OTPClient/issues/123

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