Re: [Qemu-devel] [PATCH] vnc: call sasl_server_init() only when required

["Daniel P. Berrangé" <berrange@redhat.com>]

On Fri, Aug 17, 2018 at 07:31:03PM +0200, Marc-André Lureau wrote:
> VNC server is calling sasl_server_init() during startup of QEMU, even
> if SASL auth has not been enabled.
> 
> This may create undesirable warnings like "Could not find keytab file:
> /etc/qemu/krb5.tab" when the user didn't configure SASL on host and
> started VNC server.
> 
> Instead, only initialize SASL when needed. Note that HMP/QMP "change
> vnc" calls vnc_display_open() again, which will initialize SASL if
> needed.

I could have sworn we had a way to change the VNC auth method on the
fly without restarting the whole server, but I can't find it now, so
must have been imagining it :-)

> 
> Related to:
> https://bugzilla.redhat.com/show_bug.cgi?id=1609327
> 
> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> ---
>  ui/vnc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/ui/vnc.c b/ui/vnc.c
> index 359693238b..fc507d7f36 100644
> --- a/ui/vnc.c
> +++ b/ui/vnc.c
> @@ -4054,7 +4054,7 @@ void vnc_display_open(const char *id, Error **errp)
>      trace_vnc_auth_init(vd, 1, vd->ws_auth, vd->ws_subauth);
>  
>  #ifdef CONFIG_VNC_SASL
> -    if ((saslErr = sasl_server_init(NULL, "qemu")) != SASL_OK) {
> +    if (sasl && ((saslErr = sasl_server_init(NULL, "qemu")) != SASL_OK)) {
>          error_setg(errp, "Failed to initialize SASL auth: %s",
>                     sasl_errstring(saslErr, NULL, NULL));
>          goto fail;

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>

Regards,
Daniel
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