Re: quic in-kernel implementation?

Hi,

On Wed, Jun 9, 2021 at 12:48 PM Jakub Kicinski [off-list ref] wrote:

On Tue, 8 Jun 2021 15:33:49 -0700 Stephen Hemminger wrote:

quoted

On Tue, 8 Jun 2021 17:03:16 -0400

quoted

quoted

With having the fuse-like socket before it should be trivial to switch
between the implementations.

So a good starting point would be to have such a "fuse-like socket"
component? What about having a simple example for that at first
without having quic involved. The kernel calls some POSIX-like socket
interface which triggers a communication to a user space application.
This user space application will then map everything to a user space
generated socket. This would be a map from socket struct
"proto/proto_ops" to user space and vice versa. The kernel application
probably can use the kernel_FOO() (e.g. kernel_recvmsg()) socket api
directly then. Exactly like "fuse" as you mentioned just for sockets.

I think two veth interfaces can help to test something like that,
either with a "fuse-like socket" on the other end or an user space
application. Just doing a ping-pong example.

Afterwards we can look at how to replace the user generated socket
application with any $LIBQUIC e.g. msquic implementation as second
step.

Socket state management is complex and timers etc in userspace are hard.

+1 seeing the struggles fuse causes in storage land "fuse for sockets"
is not an exciting temporary solution IMHO..

What about an in-kernel sunrpc client which forwards "in-kernel proxy
socket syscall functions" to a user server who executes those on a
user socket? Does this sound like a better approach?
Sure there may be more problems, but maybe we could try it with
something simple at first to discover all those problems.

- Alex