[Libguestfs] [PATCH v2v v3 1/2] rhv-upload: Validate UUIDs passed to -oo rhv-disk-uuid (RHBZ#1789279)

[Richard W.M. Jones]

On Wed, Mar 11, 2020 at 03:54:33PM +0100, Martin Kletzander wrote:
> The validation helps us fail early and with a sensible error message.  The NIL
> UUID is not valid for oVirt, but other than that there is no other logic in
> there merely because the UUID types are a matter of the generator and they are
> just forwarded in this partucular case.
> 
> Signed-off-by: Martin Kletzander <mkletzan at redhat.com>
> ---
>  v2v/output_rhv_upload.ml | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/v2v/output_rhv_upload.ml b/v2v/output_rhv_upload.ml
> index 9e60d8c73150..e833569318b3 100644
> --- a/v2v/output_rhv_upload.ml
> +++ b/v2v/output_rhv_upload.ml
> @@ -49,6 +49,16 @@ after their uploads (if you do, you must supply one for each disk):
>    -oo rhv-disk-uuid=UUID          Disk UUID
>  ")
>  
> +let is_nonnil_uuid uuid =
> +  let nil_uuid = "00000000-0000-0000-0000-000000000000" in
> +  let rex_uuid = lazy (
> +    let hex = "[a-fA-F0-9]" in
> +    let str = sprintf "^%s{8}-%s{4}-%s{4}-%s{4}-%s{12}$" hex hex hex hex hex in
> +    PCRE.compile str
> +  ) in
> +  if uuid = nil_uuid then false
> +  else PCRE.matches (Lazy.force rex_uuid) uuid

Actually the use of lazy here is wrong.  The regular expression
is not being created lazily at all.

You need to do something like:

let is_nonnil_uuid =
  let nil_uuid = "00000000-0000-0000-0000-000000000000" in
  let rex_uuid = lazy (
    let hex = "[a-fA-F0-9]" in
    let str = sprintf "^%s{8}-%s{4}-%s{4}-%s{4}-%s{12}$" hex hex hex hex hex in
    PCRE.compile str
  ) in
  fun uuid ->
    if uuid = nil_uuid then false
    else PCRE.matches (Lazy.force rex_uuid) uuid

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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