Merge pull request #124 from clue-labs/dump-records

Support dumping records as part of outgoing binary DNS message
reactphp · Jan 30, 2019 · 61f824d · 61f824d
2 parents 949d6f0 + e9d8149
commit 61f824d
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Showing 2 changed files with 340 additions and 9 deletions.
diff --git a/src/Protocol/BinaryDumper.php b/src/Protocol/BinaryDumper.php
@@ -2,21 +2,33 @@
 
 namespace React\Dns\Protocol;
 
-use React\Dns\Model\Message;
 use React\Dns\Model\HeaderBag;
+use React\Dns\Model\Message;
+use React\Dns\Model\Record;
 
 class BinaryDumper
 {
+    /**
+     * @param Message $message
+     * @return string
+     */
     public function toBinary(Message $message)
     {
         $data = '';
 
         $data .= $this->headerToBinary($message->header);
         $data .= $this->questionToBinary($message->questions);
+        $data .= $this->recordsToBinary($message->answers);
+        $data .= $this->recordsToBinary($message->authority);
+        $data .= $this->recordsToBinary($message->additional);
 
         return $data;
     }
 
+    /**
+     * @param HeaderBag $header
+     * @return string
+     */
     private function headerToBinary(HeaderBag $header)
     {
         $data = '';
@@ -43,20 +55,109 @@ private function headerToBinary(HeaderBag $header)
         return $data;
     }
 
+    /**
+     * @param array $questions
+     * @return string
+     */
     private function questionToBinary(array $questions)
     {
         $data = '';
 
         foreach ($questions as $question) {
-            $labels = explode('.', $question['name']);
-            foreach ($labels as $label) {
-                $data .= chr(strlen($label)).$label;
+            $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:
+                    $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;
+                default:
+                    // RDATA is already stored as binary value for unknown record types
+                    $binary = $record->data;
             }
-            $data .= "\x00";
 
-            $data .= pack('n*', $question['type'], $question['class']);
+            $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";
+        }
+
+        return $this->textsToBinary(\explode('.', $host . '.'));
+    }
 }