my $DEV = 'dev eth1';
my $count = 500;

my %special_subnets = (
   6 => [ 0, 1, 2],
  17 => [ 0, 1],
  19 => [ 0, 1, 2],
);

foreach my $oct1 ( 10 )  {
  foreach my $oct2 ( 1 .. 22 )  {
    my $third_octets_aref = $special_subnets{$oct2} || [ 0 ];
    foreach my $oct3 ( @{ $third_octets_aref } )  {
      foreach my $oct4 ( 1 .. 254 )  { # 253 ??
        print HTB generate_rule( $DEV, $count, $oct1, $oct2, $oct3, $oct4 );
        $count++;
      }
    }
  }
}

sub generate_rule {
  my ( $dev, $count, @octets ) = @_;

  my $ip = join '.', @octets;
#  my $countx = '0x' . $count;
  my $countx = sprintf '0x%04x', $count;

  return <<"END_RULE";
  
 class  add $dev parent 1:7 classid 1:$countx rate 4kbit ceil 512Kbit burst 4kbit prio 1 quantum 2000
 filter add $dev protocol ip parent 1:0 prio 1 u32 match ip dst $ip/32 match ip src 0.0.0.0/0 flowid 1:$countx
 qdisc  add $dev parent 1:$countx handle $countx: pfifo limit 5
END_RULE
}