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

[Martin Kletzander]

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
+
 let parse_output_options options =
   let rhv_cafile = ref None in
   let rhv_cluster = ref None in
@@ -71,6 +81,8 @@ let parse_output_options options =
     | "rhv-verifypeer", "" -> rhv_verifypeer := true
     | "rhv-verifypeer", v -> rhv_verifypeer := bool_of_string v
     | "rhv-disk-uuid", v ->
+       if not (is_nonnil_uuid v) then
+         error (f_"-o rhv-upload: invalid UUID for -oo rhv-disk-uuid");
        rhv_disk_uuids := Some (v :: (Option.default [] !rhv_disk_uuids))
     | k, _ ->
        error (f_"-o rhv-upload: unknown output option ‘-oo %s’") k
-- 
2.25.1