private void OnPacketReceived(UdpReceiver receiver, int localPort, IPEndPoint remoteEndPoint, byte[] packet)
{
STUNMessage stunMessage = STUNMessage.ParseSTUNMessage(packet, packet.Length);
switch (stunMessage.Header.MessageType)
{
case STUNMessageTypesEnum.Allocate:
logger.LogDebug($"MockTurnServer received Allocate request from {remoteEndPoint}.");
if (_relaySocket == null)
{
_clientEndPoint = remoteEndPoint;
// Create a new relay socket.
NetServices.CreateRtpSocket(false, _listenAddress, 0, out _relaySocket, out _);
_relayEndPoint = _relaySocket.LocalEndPoint as IPEndPoint;
logger.LogDebug($"MockTurnServer created relay socket on {_relayEndPoint}.");
_relayListener = new UdpReceiver(_relaySocket);
_relayListener.OnPacketReceived += OnRelayPacketReceived;
_relayListener.OnClosed += (reason) => logger.LogDebug($"MockTurnServer relay on {_relayEndPoint} closed.");
_relayListener.BeginReceiveFrom();
}
STUNMessage allocateResponse = new STUNMessage(STUNMessageTypesEnum.AllocateSuccessResponse);
allocateResponse.Header.TransactionId = stunMessage.Header.TransactionId;
allocateResponse.AddXORMappedAddressAttribute(remoteEndPoint.Address, remoteEndPoint.Port);
allocateResponse.AddXORAddressAttribute(STUNAttributeTypesEnum.XORRelayedAddress, _relayEndPoint.Address, _relayEndPoint.Port);
_clientSocket.SendTo(allocateResponse.ToByteBuffer(null, false), remoteEndPoint);
break;
case STUNMessageTypesEnum.BindingRequest:
logger.LogDebug($"MockTurnServer received Binding request from {remoteEndPoint}.");
STUNMessage stunResponse = new STUNMessage(STUNMessageTypesEnum.BindingSuccessResponse);
stunResponse.Header.TransactionId = stunMessage.Header.TransactionId;
stunResponse.AddXORMappedAddressAttribute(remoteEndPoint.Address, remoteEndPoint.Port);
_clientSocket.SendTo(stunResponse.ToByteBuffer(null, false), remoteEndPoint);
break;
case STUNMessageTypesEnum.CreatePermission:
logger.LogDebug($"MockTurnServer received CreatePermission request from {remoteEndPoint}.");
STUNMessage permResponse = new STUNMessage(STUNMessageTypesEnum.CreatePermissionSuccessResponse);
permResponse.Header.TransactionId = stunMessage.Header.TransactionId;
_clientSocket.SendTo(permResponse.ToByteBuffer(null, false), remoteEndPoint);
break;
case STUNMessageTypesEnum.SendIndication:
logger.LogDebug($"MockTurnServer received SendIndication request from {remoteEndPoint}.");
var buffer = stunMessage.Attributes.Single(x => x.AttributeType == STUNAttributeTypesEnum.Data).Value;
var destEP = (stunMessage.Attributes.Single(x => x.AttributeType == STUNAttributeTypesEnum.XORPeerAddress) as STUNXORAddressAttribute).GetIPEndPoint();
logger.LogDebug($"MockTurnServer relaying {buffer.Length} bytes to {destEP}.");
_relaySocket.SendTo(buffer, destEP);
break;
default:
logger.LogDebug($"MockTurnServer received unknown STUN message from {remoteEndPoint}.");
break;
}
}