Re: [Qemu-devel] [PATCH 00/15] Implement TLS support to QEMU NBD server & client

[Wouter Verhelst]

Hi Daniel,

Something occurred to me earlier today:

On Fri, Nov 27, 2015 at 12:20:38PM +0000, Daniel P. Berrange wrote:
> As is, if the client connects to a TLS enabled NBD server and then
> immediately sends NBD_OPT_EXPORT_NAME, it is not possible for us
> to send back NBD_REP_ERR_TLS_REQD as the spec requires that the
> server close the connection :-(  For this reason I have made the
> qemu NBD client always send NBD_OPT_LIST as the first thing it
> does, so that we can see the NBD_REP_ERR_TLS_REQD response.

Why not have it send NBD_OPT_STARTTLS as the first message if you want
to do TLS? That way, either the server doesn't support it because too
old (and you get NBD_REP_ERR_UNSUP) or configuration (and you get
NBD_REP_ERR_POLICY), or it does and you're in TLS.

Did I miss something?

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