Drop malformed RTP packets

// FREEBIE

jni/redphone/RtpAudioReceiver.cpp

@@ -26,6 +26,11 @@ RtpPacket* RtpAudioReceiver::receive(char* encodedData, int encodedDataLen) {
     return NULL;
   }
 
+  if (received < RtpPacket::getMinimumSize()) {
+    __android_log_print(ANDROID_LOG_WARN, TAG, "recveived malformed packet!");
+    return NULL;
+  }
+
   RtpPacket *packet = new RtpPacket(encodedData, received);
 
   if (srtpStream.decrypt(*packet, sequenceCounter.convertNext(packet->getSequenceNumber())) != 0) {

jni/redphone/RtpPacket.h

@@ -21,6 +21,10 @@ public:
   RtpPacket(char *payload, int payloadLen, int sequenceNumber, int timestamp);
   ~RtpPacket();
 
+  static int getMinimumSize() {
+    return sizeof(RtpHeader);
+  }
+
   uint16_t getSequenceNumber();
   int getPayloadType();
   uint32_t getTimestamp();