Bus1 is the new Kdbus
Judging by this description, Bus1 sounds very much like an object capability system. There is a lot of theoretical and practical evidence that this is a good programming model, and as far as I know it does not currently exist in linux. Maybe you can build a proper object capability system on top of sockets. I don&#x27;t know enough about unix domain sockets to say if it is really possible to establish the right security guarantees this way, but I&#x27;m reasonably sure that whoever is behind Bus1 has investigated this before proposing a new kernel extension. Case in point, the blog post describes a flawed implementation.<p>What really rubs me the wrong way, though, is all the negativity expressed in this blog post. Also some of the suggestions are downright dangerous. For instance:<p>&gt; (except that individual connections to a socket can be “revoked” i.e. closed, which is surely an improvement if anything)<p>This is <i>not</i> an improvement, this is another failure state that you add to every single connection, and which every single client has to handle. You can already implement this feature via proxy objects in a pure object capability system, and in this case you have to be explicit about adding another error state.<p>&gt; I think this is meant to read as “no, it’s not the D-Bus daemon functionality being subsumed in the kernel”.<p>I read the preceeding explanation as saying &quot;here is a security guarantee that clients can rely on&quot;. What is the alternative? Having unix domain sockets sprinkled somewhere in the file system where everyone with the right permissions can access them? Great, now you have to write your nodes defensively again, to guard against file system priviledge escalation, or just badly administrated systems... The Bus1 documentation is describing a feature, and one which is (afaik) not present in Linux right now.<p>&gt; Does global ordering of messages to different services ever actually matter?<p>It certainly makes proofs easier, so my intuition is to say &quot;yes&quot;. Maybe the ordering doesn&#x27;t have to be globally consistent, but better safe than sorry.