VNC pasword authentication support for the paravirt framebuffer server.

The rules for configuring the password are equivalent of those used
for HVM, but the actual guest config option is a little different as a
result of the recent refactoring of the PVFB config file syntax.

 - If the 'vfb' option in the guest config has a 'vncpasswd' parameter
   specified
      - If the passwd is not zero length, use that
      - Else run with no authentication (important as it enables
        override of next rule)
 - Else-if the xend-config.sxp has a password specified use that
 - Else run with no authentication

Example configuration:

 - To set an explicit guest password:
    vfb = [ "type=vnc,vncunused=1,vnclisten=0.0.0.0,vncpasswd=123456"]

 - To disable authentication, overriding any XenD configured
   default password
    vfb = [ "type=vnc,vncunused=1,vnclisten=0.0.0.0,vncpasswd="]

 - To run with default XenD configured password (if any)
    vfb = [ "type=vnc,vncunused=1,vnclisten=0.0.0.0"]

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

tools/python/xen/xend/server/vfbif.py

@@ -1,4 +1,5 @@
 from xen.xend.server.DevController import DevController
+from xen.xend.XendLogging import log
 
 from xen.xend.XendError import VmError
 import xen.xend
@@ -41,6 +42,17 @@ class VfbifController(DevController):
                      "--title", self.vm.getName() ]
         t = config.get("type", None)
         if t == "vnc":
+            passwd = None
+            if config.has_key("vncpasswd"):
+                passwd = config["vncpasswd"]
+            else:
+                passwd = xen.xend.XendRoot.instance().get_vncpasswd_default()
+            if not(passwd is None or passwd == ""):
+                self.vm.storeVm("vncpasswd", passwd)
+                log.debug("Stored a VNC password for vfb access")
+            else:
+                log.debug("No VNC passwd configured for vfb access")
+
             # Try to start the vnc backend
             args = [xen.util.auxbin.pathTo("xen-vncfb")]
             if config.has_key("vncunused"):

tools/python/xen/xm/create.py

@@ -284,7 +284,7 @@ gopts.var('usbport', val='PATH',
           use="""Add a physical USB port to a domain, as specified by the path
           to that port.  This option may be repeated to add more than one port.""")
 
-gopts.var('vfb', val="type={vnc,sdl},vncunused=1,vncdisplay=N,vnclisten=ADDR,display=DISPLAY,xauthority=XAUTHORITY",
+gopts.var('vfb', val="type={vnc,sdl},vncunused=1,vncdisplay=N,vnclisten=ADDR,display=DISPLAY,xauthority=XAUTHORITY,vncpasswd=PASSWORD",
           fn=append_value, default=[],
           use="""Make the domain a framebuffer backend.
           The backend type should be either sdl or vnc.
@@ -584,7 +584,7 @@ def configure_vfbs(config_devs, vals):
             d['type'] = 'sdl'
         for (k,v) in d.iteritems():
             if not k in [ 'vnclisten', 'vncunused', 'vncdisplay', 'display',
-                          'xauthority', 'type' ]:
+                          'xauthority', 'type', 'vncpasswd' ]:
                 err("configuration option %s unknown to vfbs" % k)
             config.append([k,v])
         if not d.has_key("display") and os.environ.has_key("DISPLAY"):