[libvirt] Reworked the XML verification patch for svirt

[Daniel Veillard]

On Wed, Apr 01, 2009 at 10:33:56AM -0400, Daniel J Walsh wrote:
> Main goal of this patch it to verify data being written to xml and  
> inform the user when he makes a mistake.

  This sounds good, especially about the added regression test,
but at some point we should try to hook up the RelaxNG validation
code in libxml2 and install the various XML Schemas as part of 
libvirt(d) installation. Things like testing of strings lenght,
allowed character ranges, etc are easier to write maintain and
centralize in a schemas description than in accumulated c code
checks. At least as long as the checks are not contextual it's
IMHO an easier approach.

  Still patch makes sense to me, in the current setup, but maybe
we should add a RNG validation layer as part of the next release.
This implies:
  - making sure all schemas are complete
  - hooking up the RNG validation as part of libvirt entry point.
    I assume this could be made a non-fatal error at least until
    we get more confidence in schemas.
  - make sure the "make install" and packaging set up and pick the
    schemas.

  One of the things which would need special care is making sure
the validation is done on the daemon side, not on the client when
doing remote access.

Daniel

-- 
Daniel Veillard      | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
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