/**
* Returns the binary data containing the properties of the header
*
* Packs the properties of the Header object into a binary string
* suitable for using as the Header section of a DNS packet.
*
* @return string binary representation of the header object
* @access public
*/
function data()
{
$opcode = Net_DNS::opcodesbyname($this->opcode);
$rcode = Net_DNS::rcodesbyname($this->rcode);
$byte2 = $this->qr << 7 | $opcode << 3 | $this->aa << 2 | $this->tc << 1 | $this->rd;
$byte3 = $this->ra << 7 | $rcode;
return pack('nC2n4', $this->id, $byte2, $byte3, $this->qdcount, $this->ancount, $this->nscount, $this->arcount);
}
