On Thu, Oct 20, 2016 at 05:44:41PM +0200, Pino Toscano wrote: > On Thursday, 20 October 2016 16:32:50 CEST Richard W.M. Jones wrote: > > On Thu, Oct 20, 2016 at 05:15:24PM +0200, Pino Toscano wrote: > > > Rewrite the implementation of the ssh block driver to use libssh instead > > > of libssh. The libssh library has various advantages over libssh: > > > - 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 <ptosc...@redhat.com> > > > > > > When I applied this patch and compiled it with warnings enabled: > > > > block/ssh.c: In function ‘connect_to_ssh’: > > block/ssh.c:643:12: warning: ‘ret’ may be used uninitialized in this > > function [-Wmaybe-uninitialized] > > return ret; > > ^~~ > > Interesting, there was no warning for me. Anyway, I think this: > > diff --git a/block/ssh.c b/block/ssh.c > index 7c316db..7ff376e 100644 > --- a/block/ssh.c > +++ b/block/ssh.c > @@ -519,6 +519,7 @@ static int connect_to_ssh(BDRVSSHState *s, QDict *options, > /* Create SSH session. */ > s->session = ssh_new(); > if (!s->session) { > + ret = -EINVAL; > goto err; > } > > should fix it (added already locally).
Yes, this fixes the warning. > > To test the patch, I used virt-builder to create a virtual machine > > disk image on another machine (accessible over ssh). Then from my > > laptop I ran: > > > > ./x86_64-softmmu/qemu-system-x86_64 -nodefconfig \ > > -M accel=kvm -cpu host -m 2048 \ > > -drive > > file.driver=ssh,file.user=[user],file.host=[host],file.path=/var/tmp/fedora-24.img,format=raw,if=virtio > > \ > > -serial stdio > > > > Unfortunately this failed with a large number of sftp errors: > > > > read failed: (sftp error code: 0) > > > > and subsequently hung. So I'm afraid I couldn't test the patch at all :-( > > Can you please enable the logging of the ssh driver, and libssh own > logging too? Basically (see lines 45-46) set: > > #define DEBUG_SSH 1 > #define TRACE_LIBSSH 4 I'll send you the full trace privately since it's enormous. Rich. > > Also fsync was not supported for me, but I'm using 0.7.3 and the code > > says I need 0.8.0. > > Yes, this is correct. > > Thanks, > -- > Pino Toscano -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com Fedora Windows cross-compiler. Compile Windows programs, test, and build Windows installers. Over 100 libraries supported. http://fedoraproject.org/wiki/MinGW
