Re: [Qemu-devel] [PATCH v2] ssh: switch from libssh2 to libssh

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

On Fri, Oct 21, 2016 at 01:16:11PM +0200, Pino Toscano wrote:
> Rewrite the implementation of the ssh block driver to use libssh instead
> of libssh2.  The libssh library has various advantages over libssh2:
> - easier API for authentication (for example for using ssh-agent)
> - easier API for known_hosts handling
> - supports newer types of keys in known_hosts
> 
> Kerberos authentication can be enabled once the libssh bug for it [1] is
> fixed.
> 
> The development version of libssh (i.e. the future 0.8.x) supports
> fsync, so reuse the build time check for this.
> 
> [1] https://red.libssh.org/issues/242
> 
> Signed-off-by: Pino Toscano <ptoscano@redhat.com>
> ---
> 
> Changes from v1:
> - fixed jumbo packets writing
> - fixed missing 'err' assignment
> - fixed commit message

This version works, but I also switched from using a remote server to
using this over localhost.

It seems as if the timeout might be a bit short.  Could that be made
controllable?  Or increased to match whatever libssh2 was using?

I couldn't see any other problems in the patch itself.  knownhost and
ssh-agent handling certainly seems much simpler :-)

Before I forget, there's another problem we found with the old ssh
driver: It cannot open a device on the remote side, eg. if you used:
`file.driver=ssh,file.path=/dev/sdX'  I suspect this is not solvable on
the client side, it requires changes to sshd.

Rich.

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