private void SendTo(ServerState state, GatewayPacket packet)
{
if (state.State == SERVER_STATE.Running)
{
byte[] data = null;
PACKET_TYPE type = PACKET_TYPE.PKT_UNKNOWN;
switch (packet.PacketType)
{
case PACKET_TYPE.PKT_PUSH_DATA:
data = new byte[4];
type = PACKET_TYPE.PKT_PUSH_ACK;
break;
case PACKET_TYPE.PKT_PULL_DATA:
data = new byte[12];
packet.EUI.CopyTo(data, 4);
type = PACKET_TYPE.PKT_PULL_ACK;
break;
default:
break;
}
if (type != PACKET_TYPE.PKT_UNKNOWN)
{
data[0] = packet.Version;
BitConverter.GetBytes(packet.Token).CopyTo(data, 1);
data[3] = (byte)type;
try
{
state.Socket.BeginSendTo(data, 0, data.Length, SocketFlags.None, packet.Sender, new AsyncCallback(SendToCallback), state);
}
catch (Exception ex)
{
state.ErrorSendTo = ex;
}
}
}
}
private void ReceiveFromCallback(IAsyncResult ar)
{
ServerState state = (ServerState)ar.AsyncState;
if (state.State == SERVER_STATE.Running)
{
Socket socket = state.Socket;
try
{
// Read packet from gateway
IPEndPoint ipep = new IPEndPoint(IPAddress.Any, 0);
EndPoint epSender = (EndPoint)ipep;
int bytesRead = socket.EndReceiveFrom(ar, ref epSender);
byte[] buffer = state.Buffer;
// Check packet from gateway
if (bytesRead >= 4)
{
byte version = buffer[0];
if (version == 1 || version == 2)
{
GatewayPacket packet = new GatewayPacket();
packet.Version = version;
packet.Token = BitConverter.ToUInt16(buffer, 1);
byte type = buffer[3];
switch (type)
{
case (byte)PACKET_TYPE.PKT_PUSH_DATA:
if (bytesRead > 12)
{
packet.Json = Encoding.ASCII.GetString(buffer, 12, bytesRead - 12);
packet.SetEUI(buffer);
}
else
{
packet = null;
}
break;
case (byte)PACKET_TYPE.PKT_PULL_DATA:
if (bytesRead == 12)
{
packet.SetEUI(buffer);
}
else
{
packet = null;
}
break;
case (byte)PACKET_TYPE.PKT_TX_ACK:
if (bytesRead > 4)
{
packet.Json = Encoding.ASCII.GetString(buffer, 4, bytesRead - 4);
}
else
{
packet = null;
}
break;
default:
packet = null;
break;
}
if (packet != null)
{
packet.PacketType = (PACKET_TYPE)type;
packet.Sender = epSender;
lock (state.LockPackets)
{
if (state.Packets.Count < 100)
{
state.Packets.Enqueue(packet);
}
else
{
state.LostPackets++;
}
state.ResetEvent.Set();
}
}
}
}
}
catch (Exception ex)
{
state.ErrorReceiveFromCB = ex;
}
try
{
IPEndPoint ipep = new IPEndPoint(IPAddress.Any, 0);
EndPoint epSender = (EndPoint)ipep;
socket.BeginReceiveFrom(state.Buffer, 0, state.Buffer.Length, SocketFlags.None, ref epSender, new AsyncCallback(ReceiveFromCallback), state);
}
catch (Exception ex)
{
state.ErrorReceiveFrom = ex;
}
}
}