On Wed, Sep 22, 2021 at 05:22:07PM +0800, Ming Lei wrote: > > I think this one relies on nbd protocol between server and client, and > does the protocol require both request and reply xmitted via same > socket? Yes, a reply must be transmitted on the same socket as the request came over. This is because independent sockets are not required to use distinct 64-bit handles, and there is no way for a server to tell if independent clients are related to one another; sending a reply on the wrong socket is thus not guaranteed to reach the intended client. Thus, a compliant server will never send a reply over a different socket than the original request, and if a client ever gets a reply with a handle it was not expecting, then the server is buggy or malicious. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org
