+sub IP_from_cidr {
+ my ($cidr, $version) = @_;
+
+ return if $cidr !~ m!^(\S+?)/(\S+)$!;
+ my ($ip, $prefix) = ($1, $2);
+
+ my $ipobj = Net::IP->new($ip, $version);
+ return if !$ipobj;
+
+ $version = $ipobj->version();
+
+ my $binmask = Net::IP::ip_get_mask($prefix, $version);
+ return if !$binmask;
+
+ my $masked_binip = $ipobj->binip() & $binmask;
+ my $masked_ip = Net::IP::ip_bintoip($masked_binip, $version);
+ return Net::IP->new("$masked_ip/$prefix");
+}
+
+sub is_ip_in_cidr {
+ my ($ip, $cidr, $version) = @_;
+
+ my $cidr_obj = IP_from_cidr($cidr, $version);
+ return undef if !$cidr_obj;
+
+ my $ip_obj = Net::IP->new($ip, $version);
+ return undef if !$ip_obj;
+
+ return $cidr_obj->overlaps($ip_obj) == $Net::IP::IP_B_IN_A_OVERLAP;
+}
+