public static UdpTrackerMessage DecodeMessage(byte[] buffer, int offset, int count, MessageType type)
{
UdpTrackerMessage m;
var action = type == MessageType.Request ? ReadInt(buffer, offset + 8) : ReadInt(buffer, offset);
switch (action)
{
case 0:
if (type == MessageType.Request)
m = new ConnectMessage();
else
m = new ConnectResponseMessage();
break;
case 1:
if (type == MessageType.Request)
m = new AnnounceMessage();
else
m = new AnnounceResponseMessage();
break;
case 2:
if (type == MessageType.Request)
m = new ScrapeMessage();
else
m = new ScrapeResponseMessage();
break;
case 3:
m = new ErrorMessage();
break;
default:
throw new ProtocolException(string.Format("Invalid udp message received: {0}", buffer[offset]));
}
try
{
m.Decode(buffer, offset, count);
}
catch
{
m = new ErrorMessage(0, "Couldn't decode the tracker response");
}
return m;
}
private async Task ConnectAsync()
{
var connectMessage = new ConnectMessage();
var port = Uri.IsDefaultPort ? 80 : Uri.Port;
await _tracker.ConnectAsync(new HostName(Uri.Host), port.ToString());
var responseBytes = await SendAndReceiveAsync(connectMessage);
var msg = Receive(connectMessage, responseBytes);
if (msg == null)
throw new Exception(FailureMessage);
var rsp = msg as ConnectResponseMessage;
if (rsp == null)
{
FailureMessage = ((ErrorMessage) msg).Error;
throw new Exception(FailureMessage);
}
_connectionId = rsp.ConnectionId;
_hasConnected = true;
}
