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<?php
namespace React\Dns\Protocol;
use React\Dns\Model\Message;
use React\Dns\Model\Record;
use React\Dns\Query\Query;
final class BinaryDumper
{
/**
* @param Message $message
* @return string
*/
public function toBinary(Message $message)
{
$data = '';
$data .= $this->headerToBinary($message);
$data .= $this->questionToBinary($message->questions);
$data .= $this->recordsToBinary($message->answers);
$data .= $this->recordsToBinary($message->authority);
$data .= $this->recordsToBinary($message->additional);
return $data;
}
/**
* @param Message $message
* @return string
*/
private function headerToBinary(Message $message)
{
$data = '';
$data .= pack('n', $message->id);
$flags = 0x00;
$flags = ($flags << 1) | ($message->qr ? 1 : 0);
$flags = ($flags << 4) | $message->opcode;
$flags = ($flags << 1) | ($message->aa ? 1 : 0);
$flags = ($flags << 1) | ($message->tc ? 1 : 0);
$flags = ($flags << 1) | ($message->rd ? 1 : 0);
$flags = ($flags << 1) | ($message->ra ? 1 : 0);
$flags = ($flags << 3) | 0; // skip unused zero bit
$flags = ($flags << 4) | $message->rcode;
$data .= pack('n', $flags);
$data .= pack('n', count($message->questions));
$data .= pack('n', count($message->answers));
$data .= pack('n', count($message->authority));
$data .= pack('n', count($message->additional));
return $data;
}
/**
* @param Query[] $questions
* @return string
*/
private function questionToBinary(array $questions)
{
$data = '';
foreach ($questions as $question) {
$data .= $this->domainNameToBinary($question->name);
$data .= pack('n*', $question->type, $question->class);
}
return $data;
}
/**
* @param Record[] $records
* @return string
*/
private function recordsToBinary(array $records)
{
$data = '';
foreach ($records as $record) {
/* @var $record Record */
switch ($record->type) {
case Message::TYPE_A:
case Message::TYPE_AAAA:
$binary = \inet_pton($record->data);
break;
case Message::TYPE_CNAME:
case Message::TYPE_NS:
case Message::TYPE_PTR:
$binary = $this->domainNameToBinary($record->data);
break;
case Message::TYPE_TXT:
case Message::TYPE_SPF:
$binary = $this->textsToBinary($record->data);
break;
case Message::TYPE_MX:
$binary = \pack(
'n',
$record->data['priority']
);
$binary .= $this->domainNameToBinary($record->data['target']);
break;
case Message::TYPE_SRV:
$binary = \pack(
'n*',
$record->data['priority'],
$record->data['weight'],
$record->data['port']
);
$binary .= $this->domainNameToBinary($record->data['target']);
break;
case Message::TYPE_SOA:
$binary = $this->domainNameToBinary($record->data['mname']);
$binary .= $this->domainNameToBinary($record->data['rname']);
$binary .= \pack(
'N*',
$record->data['serial'],
$record->data['refresh'],
$record->data['retry'],
$record->data['expire'],
$record->data['minimum']
);
break;
case Message::TYPE_CAA:
$binary = \pack(
'C*',
$record->data['flag'],
\strlen($record->data['tag'])
);
$binary .= $record->data['tag'];
$binary .= $record->data['value'];
break;
case Message::TYPE_SSHFP:
$binary = \pack(
'CCH*',
$record->data['algorithm'],
$record->data['type'],
$record->data['fingerprint']
);
break;
case Message::TYPE_OPT:
$binary = '';
foreach ($record->data as $opt => $value) {
if ($opt === Message::OPT_TCP_KEEPALIVE && $value !== null) {
$value = \pack('n', round($value * 10));
}
$binary .= \pack('n*', $opt, \strlen((string) $value)) . $value;
}
break;
default:
// RDATA is already stored as binary value for unknown record types
$binary = $record->data;
}
$data .= $this->domainNameToBinary($record->name);
$data .= \pack('nnNn', $record->type, $record->class, $record->ttl, \strlen($binary));
$data .= $binary;
}
return $data;
}
/**
* @param string[] $texts
* @return string
*/
private function textsToBinary(array $texts)
{
$data = '';
foreach ($texts as $text) {
$data .= \chr(\strlen($text)) . $text;
}
return $data;
}
/**
* @param string $host
* @return string
*/
private function domainNameToBinary($host)
{
if ($host === '') {
return "\0";
}
// break up domain name at each dot that is not preceeded by a backslash (escaped notation)
return $this->textsToBinary(
\array_map(
'stripcslashes',
\preg_split(
'/(?<!\\\\)\./',
$host . '.'
)
)
);
}
}
|
