/**
* @param string $question
* @param string $type
* @return DNSAnswer|false
*/
public function query($question, $type = 'A')
{
$this->clearError();
$typeid = $this->types->getByName($type);
if ($typeid === false) {
$this->setError('Invalid Query Type ' . $type);
return false;
}
if ($this->udp) {
$host = 'udp://' . $this->server;
} else {
$host = $this->server;
}
$errno = 0;
$errstr = '';
if (!($socket = fsockopen($host, $this->port, $errno, $errstr, $this->timeout))) {
$this->setError('Failed to Open Socket');
return false;
}
// handles timeout on stream read set using timeout as well
stream_set_timeout($socket, $this->timeout);
// Split Into Labels
if (preg_match('/[a-z|A-Z]/', $question) == 0 && $question != '.') {
// IP Address
// reverse ARPA format
$labels = array_reverse(explode('.', $question));
$labels[] = 'IN-ADDR';
$labels[] = 'ARPA';
} else {
if ($question == '.') {
$labels = array('');
} else {
// hostname
$labels = explode('.', $question);
}
}
$question_binary = '';
foreach ($labels as $label) {
if ($label != '') {
$size = strlen($label);
$question_binary .= pack('C', $size);
// size byte first
$question_binary .= $label;
// then the label
} else {
//$size = 0;
//$question_binary.=pack('C',$size);
//$question_binary.=pack('C',$labels[$a]);
}
}
$question_binary .= pack('C', 0);
// end it off
$this->debug('Question: ' . $question . ' (type=' . $type . '/' . $typeid . ')');
$id = rand(1, 255) | rand(0, 255) << 8;
// generate the ID
// Set standard codes and flags
$flags = 0x100 & 0x300;
// recursion & queryspecmask
$opcode = 0x0;
// opcode
// Build the header
$header = '';
$header .= pack('n', $id);
$header .= pack('n', $opcode | $flags);
$header .= pack('nnnn', 1, 0, 0, 0);
$header .= $question_binary;
$header .= pack('n', $typeid);
$header .= pack('n', 0x1);
// internet class
$headersize = strlen($header);
$headersizebin = pack('n', $headersize);
$this->debug('Header Length: ' . $headersize . ' Bytes');
$this->debugBinary($header);
if ($this->udp && $headersize >= 512) {
$this->setError('Question too big for UDP (' . $headersize . ' bytes)');
fclose($socket);
return false;
}
if ($this->udp) {
// UDP method
if (!fwrite($socket, $header, $headersize)) {
$this->setError('Failed to write question to socket');
fclose($socket);
return false;
}
if (!($this->rawbuffer = fread($socket, 4096))) {
// read until the end with UDP
$this->setError('Failed to read data buffer');
fclose($socket);
return false;
}
} else {
// TCP
// write the socket
if (!fwrite($socket, $headersizebin)) {
$this->setError('Failed to write question length to TCP socket');
fclose($socket);
return false;
}
if (!fwrite($socket, $header, $headersize)) {
$this->setError('Failed to write question to TCP socket');
fclose($socket);
return false;
}
if (!($returnsize = fread($socket, 2))) {
$this->setError('Failed to read size from TCP socket');
fclose($socket);
return false;
}
$tmplen = unpack('nlength', $returnsize);
$datasize = $tmplen['length'];
$this->debug('TCP Stream Length Limit ' . $datasize);
if (!($this->rawbuffer = fread($socket, $datasize))) {
$this->setError('Failed to read data buffer');
fclose($socket);
return false;
}
}
fclose($socket);
$buffersize = strlen($this->rawbuffer);
$this->debug('Read Buffer Size ' . $buffersize);
if ($buffersize < 12) {
$this->setError('Return Buffer too Small');
return false;
}
$this->rawheader = substr($this->rawbuffer, 0, 12);
// first 12 bytes is the header
$this->rawresponse = substr($this->rawbuffer, 12);
// after that the response
$this->responsecounter = 12;
// start parsing response counter from 12 - no longer using response so can do pointers
$this->debugBinary($this->rawbuffer);
$this->header = unpack('nid/nspec/nqdcount/nancount/nnscount/narcount', $this->rawheader);
$id = $this->header['id'];
$rcode = $this->header['spec'] & 15;
$z = $this->header['spec'] >> 4 & 7;
$ra = $this->header['spec'] >> 7 & 1;
$rd = $this->header['spec'] >> 8 & 1;
$tc = $this->header['spec'] >> 9 & 1;
$aa = $this->header['spec'] >> 10 & 1;
$opcode = $this->header['spec'] >> 11 & 15;
$type = $this->header['spec'] >> 15 & 1;
$this->debug("ID={$id}, Type={$type}, OPCODE={$opcode}, AA={$aa}, TC={$tc}, RD={$rd}, RA={$ra}, RCODE={$rcode}");
if ($tc == 1 && $this->udp) {
// Truncation detected
$this->setError('Response too big for UDP, retry with TCP');
return false;
}
$answers = $this->header['ancount'];
$this->debug('Query Returned ' . $answers . ' Answers');
$dns_answer = new DNSAnswer();
// Deal with the header question data
if ($this->header['qdcount'] > 0) {
$this->debug('Found ' . $this->header['qdcount'] . ' Questions');
for ($a = 0; $a < $this->header['qdcount']; $a++) {
$c = 1;
while ($c != 0) {
$c = hexdec(bin2hex($this->readResponse(1)));
}
$this->readResponse(4);
}
}
// New Functional Method
for ($a = 0; $a < $this->header['ancount']; $a++) {
$record = $this->readRecord();
$dns_answer->addResult(new DNSResult($record['header']['type'], $record['typeid'], $record['header']['class'], $record['header']['ttl'], $record['data'], $record['domain'], $record['string'], $record['extras']));
}
$this->lastnameservers = new DNSAnswer();
for ($a = 0; $a < $this->header['nscount']; $a++) {
$record = $this->readRecord();
$this->lastnameservers->addResult(new DNSResult($record['header']['type'], $record['typeid'], $record['header']['class'], $record['header']['ttl'], $record['data'], $record['domain'], $record['string'], $record['extras']));
}
$this->lastadditional = new DNSAnswer();
for ($a = 0; $a < $this->header['arcount']; $a++) {
$record = $this->readRecord();
$this->lastadditional->addResult(new DNSResult($record['header']['type'], $record['typeid'], $record['header']['class'], $record['header']['ttl'], $record['data'], $record['domain'], $record['string'], $record['extras']));
}
return $dns_answer;
}
