+register_format('CIDR', \&pve_verify_cidr);
+sub pve_verify_cidr {
+ my ($cidr, $noerr) = @_;
+
+ if ($cidr =~ m!^(?:$IPV4RE)(?:/(\d+))$! && ($1 > 7) && ($1 < 32)) {
+ return $cidr;
+ } elsif ($cidr =~ m!^(?:$IPV6RE)(?:/(\d+))$! && ($1 > 7) && ($1 <= 120)) {
+ return $cidr;
+ }
+
+ return undef if $noerr;
+ die "value does not look like a valid CIDR network\n";
+}
+