Re: [Qemu-devel] [PATCH] block: Add support for Secure Shell (ssh) block device.

["Richard W.M. Jones" <rjones@redhat.com>]

On Thu, Mar 21, 2013 at 08:35:29PM +0100, Stefan Hajnoczi wrote:
> On Thu, Mar 21, 2013 at 2:38 PM, Richard W.M. Jones <rjones@redhat.com> wrote:
> > From: "Richard W.M. Jones" <rjones@redhat.com>
> >
> >   qemu-system-x86_64 -drive file=ssh://hostname/some/image
> >
> > QEMU will ssh into 'hostname' and open '/some/image' which is made
> > available as a standard block device.
> >
> > You can specify a username (ssh://user@host/...) and/or a port number
> > (ssh://host:port/...).
> >
> > Current limitations:
> >
> > - Authentication must be done without passwords or passphrases, using
> >   ssh-agent.  Other authentication methods are not supported. (*)
> >
> > - Does not check host key. (*)
> >
> > - New remote files cannot be created. (*)
> >
> > - Uses coroutine read/write, instead of true AIO.  (libssh2 supports
> >   non-blocking access, so this could be fixed with some effort).
> >
> > - Blocks during connection and authentication.
> >
> > (*) = potentially easy fix
> >
> > This is implemented using libssh2 on the client side.  The server just
> > requires a regular ssh daemon with sftp-server support.  Most ssh
> > daemons on Unix/Linux systems will work out of the box.
> > ---
> >  block/Makefile.objs |   1 +
> >  block/ssh.c         | 514 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  configure           |  47 +++++
> >  qemu-doc.texi       |  28 +++
> >  4 files changed, 590 insertions(+)
> >  create mode 100644 block/ssh.c
> 
> Just noticed that libcurl supports sftp.
> 
> Did you try enabling sftp support in block/curl.c?  I think you just
> need to add CURLPROTO_SFTP to #define PROTOCOLS.

Interestingly curl's sftp support is implemented using libssh2.  I'll
take a look at how easy this will be.

Rich.

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