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

Richard W.M. Jones rjones at redhat.com
Sat Sep 28 09:25:43 UTC 2019


On Fri, Sep 27, 2019 at 10:22:10PM -0500, Eric Blake wrote:
> 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.

Yes good idea - I sent a patch.  It needs a test which I can get
around to later.

Rich.

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