[Libguestfs] [PATCH nbdkit 0/4] Reflection plugin, peer name.

[Eric Blake]

On 9/15/19 9:55 AM, Richard W.M. Jones wrote:

> The fun plugin is a reflection plugin which "reflects" client
> information back to the client.  We have a few fun plugins like this
> (hello there, nbdkit-full-plugin) and normally I would push these
> without review, but in this particular case there's a specific danger
> that sending back data under control of the client might lead to a
> security problem.  I _believe_ I have avoided that pitfall, but my
> belief isn't as good as having experts review it :-)
> 

A thought for another potentially fun mode: what if the reflection 
plugin reports back connection uptime?  The disk would be a fixed-width 
size (maybe 8 bytes: uint32_t for seconds, uint32_t for nanoseconds), 
where the contents are always changing to record the delta in time 
between any given request and when the connection was first created (in 
this mode, multi-conn and caching contents is actually quite wrong). 
Back-to-back commands can in turn be used to measure connection latencies.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org