Support parsing SRV records

examples/11-query-any.php

@@ -48,6 +48,11 @@
                 $type = 'MX';
                 $data = implode(' ', $data);
                 break;
+            case Message::TYPE_SRV:
+                // SRV records contains priority, weight, port and target, dump structure here
+                $type = 'SRV';
+                $data = json_encode($data);
+                break;
             case Message::TYPE_SOA:
                 // SOA records contain structured data, dump structure here
                 $type = 'SOA';

src/Model/Message.php

@@ -14,6 +14,7 @@ class Message
     const TYPE_MX = 15;
     const TYPE_TXT = 16;
     const TYPE_AAAA = 28;
+    const TYPE_SRV = 33;
     const TYPE_ANY = 255;
 
     const CLASS_IN = 1;

src/Model/Record.php

@@ -56,6 +56,18 @@ class Record
      *   referred to as exchange). If a response message contains multiple
      *   records of this type, targets should be sorted by priority (lowest
      *   first) - this is left up to consumers of this library (used for SMTP).
+     * - SRV:
+     *   Service priority (UINT16), service weight (UINT16), service port (UINT16)
+     *   and target hostname without trailing dot, for example
+     *   `{"priority":10,"weight":50,"port":8080,"target":"example.com"}`.
+     *   The payload data uses an associative array with fixed keys "priority",
+     *   "weight", "port" and "target" (also referred to as name).
+     *   The target may be an empty host name string if the service is decidedly
+     *   not available. If a response message contains multiple records of this
+     *   type, targets should be sorted by priority (lowest first) and selected
+     *   randomly according to their weight - this is left up to consumers of
+     *   this library, see also [RFC 2782](https://tools.ietf.org/html/rfc2782)
+     *   for more details.
      * - SOA:
      *   Includes master hostname without trailing dot, responsible person email
      *   as hostname without trailing dot and serial, refresh, retry, expire and

src/Protocol/Parser.php

@@ -185,6 +185,16 @@ public function parseAnswer(Message $message)
                 'priority' => $priority,
                 'target' => implode('.', $bodyLabels)
             );
+        } elseif (Message::TYPE_SRV === $type) {
+            list($priority, $weight, $port) = array_values(unpack('n*', substr($message->data, $consumed, 6)));
+            list($bodyLabels, $consumed) = $this->readLabels($message->data, $consumed + 6);
+
+            $rdata = array(
+                'priority' => $priority,
+                'weight' => $weight,
+                'port' => $port,
+                'target' => implode('.', $bodyLabels)
+            );
         } elseif (Message::TYPE_SOA === $type) {
             list($primaryLabels, $consumed) = $this->readLabels($message->data, $consumed);
             list($mailLabels, $consumed) = $this->readLabels($message->data, $consumed);

tests/Protocol/ParserTest.php

@@ -331,6 +331,39 @@ public function testParseMXResponse()
         $this->assertSame(array('priority' => 10, 'target' => 'hello'), $response->answers[0]->data);
     }
 
+    public function testParseSRVResponse()
+    {
+        $data = "";
+        $data .= "04 69 67 6f 72 02 69 6f 00";          // answer: igor.io
+        $data .= "00 21 00 01";                         // answer: type SRV, class IN
+        $data .= "00 01 51 80";                         // answer: ttl 86400
+        $data .= "00 0C";                               // answer: rdlength 12
+        $data .= "00 0a 00 14 1F 90 04 74 65 73 74 00"; // answer: rdata priority 10, weight 20, port 8080 test
+
+        $data = $this->convertTcpDumpToBinary($data);
+
+        $response = new Message();
+        $response->header->set('anCount', 1);
+        $response->data = $data;
+
+        $this->parser->parseAnswer($response);
+
+        $this->assertCount(1, $response->answers);
+        $this->assertSame('igor.io', $response->answers[0]->name);
+        $this->assertSame(Message::TYPE_SRV, $response->answers[0]->type);
+        $this->assertSame(Message::CLASS_IN, $response->answers[0]->class);
+        $this->assertSame(86400, $response->answers[0]->ttl);
+        $this->assertSame(
+            array(
+                'priority' => 10,
+                'weight' => 20,
+                'port' => 8080,
+                'target' => 'test'
+            ),
+            $response->answers[0]->data
+        );
+    }
+
     public function testParseResponseWithTwoAnswers()
     {
         $data = "";