LittleSnitch for Linux

obdev.at

449 points by pluc 6 hours ago


alhazrod - 6 hours ago

I remember before Little Snitch there was ZoneAlarm for Windows[0] (here is a good screenshot[1]). No clue if the current version of ZoneAlarm does anything like that (have not used it in 2 decades). I always found it weird that Linux never really had anything like it.

[0]: https://en.wikipedia.org/wiki/ZoneAlarm

[1]: https://d2nwkt1g6n1fev.cloudfront.net/helpmax/wp-content/upl...

microtonal - 10 minutes ago

Wow. I have used Little Snitch on Mac for years, love this!

If anyone from obdev is reading, please give us a way to pay for it, even if it stays free :), I'd love to support development and would happily pay something between the price of Little Snitch and Little Snitch Mini.

Anyway, thanks a lot!

Bromeo - 6 hours ago

How does it compare to opensnitch? https://github.com/evilsocket/opensnitch

xn--yt9h - 11 minutes ago

Giving it a shot right now. Very easy setup, intuitive UI, but a lot of requests' processes are not identified (while they could easily be identified, as they belong to the browser that has some, but less, identified calls)

parhamn - 4 hours ago

Okay hear me out, I use little snitch for a while. Great product. Love finding out what phones where. I make every single request (except my browser, because I'm fine with their sandbox) block until I approve.

Recently I was wondering how you really have to trust something like little snitch given its a full kernel extension effectively able to MITM your whole network stack.

So I went digging (and asked some agents to deep research), and I couldn't find much interesting about the company or its leadership at all.

All a long way to say, anyone know anything about this company?

mathfailure - 5 hours ago

Nice to have this as an extra option, but being a linux user I value openness of code. I am pretty content with opensnitch + opensnitch-ui.

wolvoleo - 25 minutes ago

Ohhh interesting. Little snitch is one of 2 apps I miss from when the Mac was my daily driver. The other app was pixelmator

tankenmate - an hour ago

I'm so surprised that so few people have heard of Portmaster, it's been around for years and runs on Linux (and Windows if you must). And if you don't need traffic history it's free.

Cider9986 - 5 hours ago

This has the author's blog post on it https://obdev.at/blog/little-snitch-for-linux/

TheTaytay - 3 hours ago

I’ve been researching the “best” way to build a little outbound network proxy to replace credential placeholders with the real secrets. Since this is designed to secure agents workloads, I figured I might as well add some domain blocking, and other outbound network controls, so I’ve been looking for Little-snitch-like apps to build on. I’ve been surprised to find that there aren’t a ton of open source “filter and potentially block all outbound connections according to rules”. This seems like the sort of thing that would be in a lot of Linux admins’ toolkit, but I guess not! I appreciate these guys building and releasing this.

Avicebron - 5 hours ago

Probably should throw it out there that I'm building something inspired by littleSnitch for windows. Currently a bit stealthy about it. But when I crowd source the funding for a code signing cert I'll get it out there. Lots of inspiration from LittleSnitch, in spirit if not actual code.

adrianwaj - 2 hours ago

There was a similar Show HN from 3 weeks ago. https://news.ycombinator.com/item?id=47387443 (open source too) - and there is a live window from all the machines in the swarm. https://dialtoneapp.com/explore - but only 2 so far. Maybe LittleSnitch can generate more data than this? Could end up an immune system for bad actors.

Anything new to get much better performance from low-spec machines that is idiot-proof is a game-changer.

mostlysimilar - 5 hours ago

Incredible. LittleSnitch is must-have for macOS and trying to get equivalent functionality on Linux was painful. So very happy to see this, and very happy to give the developers at Objective Development my money.

winrid - 2 hours ago

Related - I'm working on launching Watch.ly[0] (human-in-the-loop for remotely approving network and file system access for agents) in the next week or so. It works similarly, via eBPF (although we can also fall back to NFQUEUE). Supporting 5.x+ linux kernels[1], osx, and windows.

Did not know about LittleSnitch, will definitely check it out.

[0] https://watch.ly/

[1] https://app.watch.ly/status/

hackingonempty - 6 hours ago

LittleSnitch doesn't tattle on itself phoning home.

eviks - an hour ago

Does it leak your IP like the Mac version?

https://news.ycombinator.com/item?id=35363343

> Little Snitch for Linux is not a security tool.

Maybe not?

> Its focus is privacy:

Or maybe yes?

alsetmusic - 4 hours ago

Congrats to Linux users on getting a great tool from a quality development shop. Objective Development is one of our (Mac users) exemplars for attention to detail and fit & finish.

Congrats to Objective Development for expanding their well-loved tool to a new platform. You guys rock.

0xbadcafebee - 2 hours ago

> Compatible with Linux kernel 6.12 or higher

I know everyone today is used to upgrading every 5 seconds, but some of us are stuck on old software. For example, my Linux machine keeps rebooting and sucks up power in suspend mode because of buggy drivers in 6.12+, so I'm stuck on 6.8. (which is extra annoying because I bought this laptop for its Linux hardware support...)

txrx0000 - 4 hours ago

As articulated in the author's own blog post:

https://obdev.at/blog/little-snitch-for-linux/

The core issue is simple and uncomfortable: through automatic updates, a vendor can run any code, with any privileges, on your machine, at any time.

-----

If the author is serious about this, then they should make their own program completely open source, and make builds bit-for-bit reproducible.

For all I know, the proprietary Little Snitch daemon, or even the binaries they're distributing for the open source components, contain backdoors that can be remotely activated to run any code, with any privileges, on your machine, at any time.

badc0ffee - 3 hours ago

Does anyone know how the blocking functionality works? I worked on some eBPF code a few years ago (when BTF/CO-RE was new), and while it was powerful, you couldn't just write to memory, or make function calls in the kernel.

Is there a userland component that's using something like iptables? (Can iptables block traffic originating from/destined to a specific process nowadays?)

mrbluecoat - 4 hours ago

> The macOS version uses deep packet inspection to do this more reliably. That's not an option here.

Isn't MacOS just *nix under the hood? Genuinely curious about this difference.

Dig1t - 5 hours ago

>The daemon (littlesnitch --daemon) is proprietary, but free to use and redistribute.

Worth noting that it is closed source. Would be worth contributing patches to OpenSnitch to bring it up to parity with Little Snitch.

https://github.com/evilsocket/opensnitch

flexagoon - 4 hours ago

Also see Safing Port master:

https://safing.io/

SamuelAdams - 6 hours ago

So if this is free to use on linux, what is to stop someone from doing what Colima did to Docker? Aka make a tiny Linux VM on MacOS and package Little Snitch within that?

imagetic - an hour ago

Dope.

FloatArtifact - 5 hours ago

I wish applications like this could coordinate with upstream firewall like opnsense

chris_wot - 3 hours ago

Can someone elaborate on the limitations bit?

"Little Snitch for Linux is built for privacy, not security, and that distinction matters. The macOS version can make stronger guarantees because it can have more complexity. On Linux, the foundation is eBPF, which is powerful but bounded: it has strict limits on storage size and program complexity. Under heavy traffic, cache tables can overflow, which makes it impossible to reliably tie every network packet to a process or a DNS name. And reconstructing which hostname was originally looked up for a given IP address requires heuristics rather than certainty. The macOS version uses deep packet inspection to do this more reliably. That's not an option here."

Is this a limitation of the eBPF implementation? Pardon my ignorance, I'm genuinely curious about this.

rvz - 6 hours ago

Also from [0].

> You can find Little Snitch for Linux here. It is free, and it will stay that way.

Don't worry, the authors know that there's no point in charging Linux users. Unlike Mac users.

So you might as well make it $0 and the (Linux) crowd goes wild that they don't need to pay a cent.

However...

> I researched a bit, found OpenSnitch, several command line tools, and various security systems built for servers. None of these gave me what I wanted: see which process is making which connections, and in the best case deny with a single click.

OpenSnitch is open source. You don't need to trust it as you can see the code yourself. Little Snitch on the other hand, is completely closed source.

Do you still trust them not to do self-reporting or phoning home, even though it is $0 and closed source?

[0] https://obdev.at/blog/little-snitch-for-linux/

LoganDark - 3 hours ago

Yess, the return of the actually good landing page for the technically-minded. Now all they need to do is roll back the macOS one that looks and reads like it was designed by a marketing agency that knows nothing about computers (or even Little Snitch itself).

computing - 3 hours ago

doesn't work on arch (btw)

sneak - 3 hours ago

It’s not really necessary on Linux. Linux systems work without 40 invisible background services phoning home to the mothership to leak your hardware identifiers for FAA702 collection.

waterTanuki - 5 hours ago

Why would one use this over PiHole?

VladVladikoff - 4 hours ago

Really like Lulu as an alternative to LittleSnitch https://objective-see.org/products/lulu.html

serious_angel - 5 hours ago

  > The macOS version can make stronger guarantees because it can have more complexity. On Linux, the foundation is eBPF, which is powerful but bounded: it has strict limits on storage size and program complexity. Under heavy traffic, cache tables can overflow, which makes it impossible to reliably tie every network packet to a process or a DNS name.  
  > And reconstructing which hostname was originally looked up for a given IP address requires heuristics rather than certainty. The macOS version uses deep packet inspection to do this more reliably.  
  > That's not an option here.
  > 
  > Source: https://web.archive.org/web/20260409002901/https://obdev.at/products/littlesnitch-linux/index.html
The above feels like an utter AI slop nonsense, sorry. I believe eBPF, the Linux Kernel feature, is absolutely capable for accuracy and perfect processing of network traffic.

Have you ever checked Calico or Cilium, or at least, Oryx?

shawnta - an hour ago

Great website features, exactly what I needed, thank you.