the common practice is to relax the dependencies

I found this a bit disturbing

I find that funny that, since this is rust, this is now an issue.

I have not dwelved in packaging in a long while, but I remember that this was already the case for C programs. You need to link against libfoo? It better work with the one the distribution ship with. What do you mean you have not tested all distributions? You better have some tests to catch those elusive ABI/API breakage. And then, you have to rely on user reported errors to figure out that there is an issue.

On one hand, the package maintainer tend to take full ownership and will investigate issues that look like integration issue themselves. On the other hand, your program is in a buggy or non-working state until that’s sorted.

And the usual solutions are frown upon. Vendoring the dependencies or static linking? Are you crazy? You’re not the one paying for bandwidth and storage. Which is a valid concern, but that just mean we reached a stalemate.

Which is now being broken by

• slower moving C/C++ projects (though the newer C++ standards did some waves a few years back) which means that even Debian is likely to have a “recent” enough version of your dependencies.
• flatpack and the likes, which are vendoring everything and the kitchen sink
• newer languages that static link by default (and some distributions being OK with it)

In other words, we never figured out a proper solution for C projects that will link with a different minor than the one the developer tested.

Well, /rant I guess. The point I’m raising does not seem to be the only one, and maybe far from the main one, for which bcachefs-tools is now orphaned. But I’ve seen very dubious arguments to try and push back against rust adoption. I feel like people have forgotten where we came from. And while there is no reason to go back per say, any new language that integrate this deep into the system will face similar challenges.

I don’t think that’s the issue. As said in the article, the researchers found the flaw by reading the architecture documentation. So the flaw is in the design of the API the operating system uses to configure the CPU and related resources. This API is public (though not open source) as to allow operating system vendors to do their job. It usually comes with examples and pseudo code on how some operations work. Here is an example (PDF).

Knowing how this feature is actually implemented in hardware (if the hardware was open source) would not have helped much. I would argue you are one level too low to properly understand the consequences of the implementation.

By the vague description in the article it actually looks like a meltdown or specter like issue where some code gets executed with the inappropriate privileges. Such issues are inherent to complex designs and no amount of open-source will save you there. We need a cultural and maybe a paradigm shift on how we design CPU to fully address those issues.

Enable permissions for KMS capture.

Warning

Capture of most Wayland-based desktop environments will fail unless this step is performed.

Note

cap_sys_admin may as well be root, except you don’t need to be root to run it. It is necessary to allow Sunshine to use KMS capture.

Enable

   sudo setcap cap_sys_admin+p $(readlink -f $(which sunshine))

Disable (for Xorg/X11 only)

   sudo setcap -r $(readlink -f $(which sunshine))

Their install instruction are pretty clear to me. The actual instruction is to run

sudo setcap cap_sys_admin+p $(readlink -f $(which sunshine))

This is vaguely equivalent to setting the setuid bit on programs such as sudo which allows you to run as root. Except that the program does not need to be owned by root. There are also some other subtleties, but as they say, it might as well be the same as running the program directly as root. For the exact details, see here: https://www.man7.org/linux/man-pages/man7/capabilities.7.html and look for CAP_SYS_ADMIN.

In other words, the commands gives all powers to the binary. Which is why it can capture everything.

Using KMS capture seems way overkill for the task I would say. But maybe the wayland protocol was not there yet when this came around or they need every bit of performance they can gain. Seeing the project description, I would guess on the later as a cloud provider would dedicate a machine per user and would then wipe and re-install between two sessions.

This looks like one of those wireguard based solution like tailscale or netbird though I’m not sure they are using it here. They all use a public relay used for NAT penetration as well as client discovery and in some instance, when NAT pen fails, traffic relay. From the usage, this seems to be the case here as well:

Share the local Minecraft server:

$ holesail --live 25565 --connector “holesailMCServer420”

On other computer(s):

$ holesail “holesailMCServer420”

So this would register a “holesailMCServer420” on their relay server. The clients could then join this network just by knowing its name and the relay will help then reach the host of the Minecraft server. I’m just extrapolating from the above commands though. They could be using DHT for client discovery. But I expect they’d need some form of relay for NAT pen at the very least.

As for exposing your local network securely, wireguard based solution allow you to change the routing table of the peers as well as the DNS server used to be able to assign domain name to IPs only reachable from within another local network. In this instance, it works very much like a VPN except that the connection to the VPN gateway is done through a P2P protocol rather than trough a service directly exposed to the internet.

Though in the instance of holesail, I have heavy doubts about “securely” as no authentication seems required to join a network: you just need to know its name. And there is no indication that choosing a fully random name is enough.

This is what was used by Benjamin to fix David’s issue with his XPPen stylus. Here is the mail thread where this was discussed.

It’s nice to see it documented now. Hopefully this will extend the support of weird devices such as tablets and game controllers since it should allow user space to “fix” them.