#!/usr/bin/perl
use Net::DNS;
use strict;
$|++;

my $res = Net::DNS::Resolver->new();

my $dom = shift || 'example.com';
my $count = shift || 10000;
my $each = shift || 1000;

my $start = time;
my $end;

for( my $time = $start, my $n = 0; $n<$count; $n++ ) {
  my $rand = int(rand(2**32-1));
  $rand = join(".",unpack("CCCC",pack("H*", sprintf "%08lx", $rand)));
  $rand .= '.' . $dom;
  do_query($rand, 'A');

  if (($n+1) % $each == 0) {
    my $t = time;
    printf "%d %d %d %d\n", $t, $time, $t-$time, int(1000*($t-$time)/$each);
    $time = $end = $t;
  }
}

printf "%d %d %d %d\n", $end, $start, $end-$start, int(1000*($end-$start)/$count);

sub do_query {
  my($query, $type) = @_;
  my $RR = $res->query($query, $type);

  if (!$RR && $res->errorstring ne 'NXDOMAIN') {
      warn "dns: query failed: $query => " . $res->errorstring;
  }
}