Building a Netfilter firewall module
SINGING
We’ll show you how to build your own Netfilter extension with this example of a musical firewall.
Netfilter is the Linux kernel subsystem behind firewall tools such as the famous Iptables. The Netfilter subsystem provides the structure for packet filtering and address translation by offering a series of hooks into the network protocol stack. You can find many commands, scripts, and front-end applications for accessing the Netfilter subsystem – including tools such as Shorewall and Firestarter, as well as the native Iptables – so you don’t have to be a programmer to access the powers of Netfilter. However, if you are ready for a little programming, you can use the built-in Netfilter hooks to create your own custom firewall modules.
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
Linux 7.4 is "Much Healthier" Thanks to AI
At nearly 42 million lines, Linux 7.4 is the largest merge in the kernel’s history.
-
Working Exploit for a Linux Kernel Flaw Made Public
Even before a bug received its CVE identifier or an upstream fix, the local privilege escalation vulnerability exploit found its way into the wild.
-
r/opensource Bans AI-Assisted and AI-Related Projects
The de facto subreddit for all things open source has not only banned AI-related projects but also users who "don't speak English."
-
Bottlenecks Discovered by Meta Engineers Lead to Scalability Improvements
Thanks to a small group of engineers at Meta, the Linux kernel module kernfs has been improved, which has led to some serious gains.
-
PwnEscape Poses VM Vulnerability
A guest-to-host escape flaw in Linux KVM, named PwnEscape, might be yet another means of attacking Linux.
-
Linux Mint 27 Set for a Christmas Release
The developers behind Linux Mint have announced a Christmas release, and it looks like Santa's sack will be brimming with features.
-
Is Linus Torvalds Vibe Coding?
The creator of Linux has added AI into his process for Linux kernel development, and it's more than just for debugging.
-
openKylin 3.0 Released with Expanded AI Integration
The latest release features a pre-installed AI agent to help perform tasks.
-
DigitalOcean Ends Open Source Credits Program
In a change that has surprised many open source developers, DigitalOcean has decided to sunset its Open Source Credits Program.
-
Office 365 Available for Testing on Linux via Bottles
Linux users can now test the official Office 365, thanks to Mirko Brombin's work on Bottles.