private async void MessageReceived(DatagramSocket sender, DatagramSocketMessageReceivedEventArgs args)
{
try
{
// accessing the properties of args seems to throw exceptions
if (args.RemoteAddress.Type != HostNameType.Ipv4)
{
// TODO support other types once the rest of Falcon does
Log(LogLevel.Warning, String.Format("Dropped Message - Remote peer: {0} unsupported type: {1}.", args.RemoteAddress.RawName, args.RemoteAddress.Type));
return;
}
if (args.RemoteAddress.RawName.StartsWith("127.") && args.RemotePort == localPortAsString)
{
Log(LogLevel.Warning, "Dropped Message received from self.");
return;
}
IPv4EndPoint lastRemoteEndPoint = new IPv4EndPoint(args.RemoteAddress.RawName, args.RemotePort); // careful todo this within the lock so doesn't get re-assigned while we are using it
DataReader dr = args.GetDataReader();
int size = (int)dr.UnconsumedBufferLength;
if (size == 0)
{
// peer has closed
TryRemovePeer(lastRemoteEndPoint);
return;
}
else if (size < Const.NORMAL_HEADER_SIZE || size > Const.MAX_DATAGRAM_SIZE)
{
Log(LogLevel.Error, String.Format("Message dropped from peer: {0}, bad size: {0}", lastRemoteEndPoint, size));
return;
}
byte seq = dr.ReadByte();
byte packetInfo = dr.ReadByte();
// parse packet info byte
HeaderPayloadSizeType hpst = (HeaderPayloadSizeType)(packetInfo & Const.PAYLOAD_SIZE_TYPE_MASK);
SendOptions opts = (SendOptions)(packetInfo & Const.SEND_OPTS_MASK);
PacketType type = (PacketType)(packetInfo & Const.PACKET_TYPE_MASK);
// check the header makes sense
if (!Enum.IsDefined(Const.HEADER_PAYLOAD_SIZE_TYPE_TYPE, hpst)
|| !Enum.IsDefined(Const.SEND_OPTIONS_TYPE, opts)
|| !Enum.IsDefined(Const.PACKET_TYPE_TYPE, type))
{
Log(LogLevel.Warning, String.Format("Message dropped from peer: {0}, bad header.", lastRemoteEndPoint));
return;
}
// parse payload size
int payloadSize;
if (hpst == HeaderPayloadSizeType.Byte)
{
payloadSize = dr.ReadByte();
}
else
{
if (size < Const.LARGE_HEADER_SIZE)
{
Log(LogLevel.Error, String.Format("Message with large header dropped from peer: {0}, size: {1}.", lastRemoteEndPoint, size));
return;
}
payloadSizeBytes[0] = dr.ReadByte();
payloadSizeBytes[1] = dr.ReadByte();
payloadSize = BitConverter.ToUInt16(payloadSizeBytes, 0);
}
// validate payload size
if (payloadSize != dr.UnconsumedBufferLength)
{
Log(LogLevel.Error, String.Format("Message dropped from peer: {0}, payload size: {1}, not as specefied: {2}", lastRemoteEndPoint, dr.UnconsumedBufferLength, payloadSize));
return;
}
// copy the payload
byte[] payload = null;
if (payloadSize > 0)
{
payload = new byte[payloadSize];
dr.ReadBytes(payload);
}
RemotePeer rp;
if (!peersByIp.TryGetValue(lastRemoteEndPoint, out rp))
{
// Could be the peer has not been added yet and is requesting to be added.
// Or it could be we are asking to be added and peer is accepting!
if (type == PacketType.AddPeer)
{
string pass = null;
if (payloadSize > 0)
pass = Settings.TextEncoding.GetString(payload, 0, payloadSize);
if (pass != networkPass) // TODO something else?
{
// TODO send reject and reason
Log(LogLevel.Info, String.Format("Join request dropped from peer: {0}, bad pass.", lastRemoteEndPoint));
}
else if (peersByIp.ContainsKey(lastRemoteEndPoint))
{
// TODO send reject and reason
Log(LogLevel.Warning, String.Format("Join request dropped from peer: {0}, peer is already added!", lastRemoteEndPoint));
}
else
{
rp = await TryAddPeerAsync(lastRemoteEndPoint);
if(rp != null)
rp.BeginSend(SendOptions.Reliable, PacketType.AcceptJoin, null, null);
}
}
else if (type == PacketType.AcceptJoin)
{
AwaitingAcceptDetail detail;
if (!TryGetAndRemoveWaitingAcceptDetail(lastRemoteEndPoint, out detail))
{
// Possible reasons we do not have detail are:
// 1) Accept is too late,
// 2) Accept duplicated and we have already removed it, or
// 3) Accept was unsolicited.
Log(LogLevel.Warning, String.Format("Accept dropped from peer: {0}, join request not found.", lastRemoteEndPoint));
}
else
{
// create the new peer, add the datagram to send ACK, call the callback
rp = await TryAddPeerAsync(lastRemoteEndPoint);
if (rp != null)
{
rp.AddReceivedPacket(seq, opts, type, payload);
TryResult tr = new TryResult(true, null, null, rp.Id);
detail.Callback(tr);
}
}
}
else
{
Log(LogLevel.Warning, String.Format("Message dropped from peer: {0}, peer unknown.", lastRemoteEndPoint));
}
}
else
{
rp.AddReceivedPacket(seq, opts, type, payload);
}
}
catch (Exception ex)
{
Log(LogLevel.Error, String.Format("Exception in MessageReceived handler: {0}.", ex.Message));
}
}
private void Listen()
{
while (true)
{
if (stop)
return;
int sizeReceived = 0;
try
{
//-------------------------------------------------------------------------
sizeReceived = Sock.ReceiveFrom(receiveBuffer, ref lastRemoteEndPoint);
//-------------------------------------------------------------------------
IPEndPoint ip = (IPEndPoint)lastRemoteEndPoint;
// Do not listen to packets sent by us to us. This only drops packets from the
// same instance of Falcon (i.e. on the same port) so we can still send/recv
// packets from another instance of Falcon (i.e. on different port) on the
// same host.
if (IPAddress.IsLoopback(ip.Address) && ip.Port == localPort)
{
Log(LogLevel.Warning, "Dropped datagram received from self.");
continue;
}
if (sizeReceived == 0)
{
// peer closed connection
TryRemovePeer(ip);
continue;
}
else if (sizeReceived < Const.NORMAL_HEADER_SIZE || sizeReceived > Const.MAX_DATAGRAM_SIZE)
{
Log(LogLevel.Error, String.Format("Datagram dropped from peer: {0}, bad size: {0}", lastRemoteEndPoint, sizeReceived));
return;
}
byte seq = receiveBuffer[0];
byte packetInfo = receiveBuffer[1];
// parse packet info byte
HeaderPayloadSizeType hpst = (HeaderPayloadSizeType)(packetInfo & Const.PAYLOAD_SIZE_TYPE_MASK);
SendOptions opts = (SendOptions)(packetInfo & Const.SEND_OPTS_MASK);
PacketType type = (PacketType)(packetInfo & Const.PACKET_TYPE_MASK);
// check the header makes sense
if (!Enum.IsDefined(Const.HEADER_PAYLOAD_SIZE_TYPE_TYPE, hpst)
|| !Enum.IsDefined(Const.SEND_OPTIONS_TYPE, opts)
|| !Enum.IsDefined(Const.PACKET_TYPE_TYPE, type))
{
Log(LogLevel.Warning, String.Format("Datagram dropped from peer: {0}, bad header.", lastRemoteEndPoint));
return;
}
// read payload
int payloadSize;
byte[] payload = null;
if (hpst == HeaderPayloadSizeType.Byte)
{
payloadSize = receiveBuffer[2];
// validate payload size
if (payloadSize != (sizeReceived - Const.NORMAL_HEADER_SIZE))
{
Log(LogLevel.Error, String.Format("Datagram dropped from peer: {0}, payload size: {1}, not as specefied: {2}", lastRemoteEndPoint, (sizeReceived - Const.NORMAL_HEADER_SIZE), payloadSize));
return;
}
if (payloadSize > 0)
{
payload = new byte[payloadSize];
System.Buffer.BlockCopy(receiveBuffer, Const.NORMAL_HEADER_SIZE, payload, 0, payloadSize);
}
}
else
{
if (sizeReceived < Const.LARGE_HEADER_SIZE)
{
Log(LogLevel.Error, String.Format("Datagram with large header dropped from peer: {0}, size: {1}.", lastRemoteEndPoint, sizeReceived));
return;
}
payloadSizeBytes[0] = receiveBuffer[2];
payloadSizeBytes[1] = receiveBuffer[3];
payloadSize = BitConverter.ToUInt16(payloadSizeBytes, 0);
// validate payload size
if (payloadSize != (sizeReceived - Const.LARGE_HEADER_SIZE))
{
Log(LogLevel.Error, String.Format("Datagram dropped from peer: {0}, payload size: {1}, not as specefied: {2}", lastRemoteEndPoint, (sizeReceived - Const.LARGE_HEADER_SIZE), payloadSize));
return;
}
payload = new byte[payloadSize];
System.Buffer.BlockCopy(receiveBuffer, Const.NORMAL_HEADER_SIZE, payload, 0, payloadSize);
}
RemotePeer rp;
if (!peersByIp.TryGetValue(ip, out rp))
{
// Could be the peer has not been added yet and is requesting to be added.
// Or it could be we are asking to be added and peer is accepting!
if (type == PacketType.AddPeer)
{
string pass = null;
if (payloadSize > 0)
pass = Settings.TextEncoding.GetString(receiveBuffer, Const.NORMAL_HEADER_SIZE, payloadSize);
if (pass != networkPass) // TODO something else?
{
// TODO send reject and reason
Log(LogLevel.Info, String.Format("Join request from: {0} dropped, bad pass.", ip));
}
else if (peersByIp.ContainsKey(ip))
{
// TODO send reject and reason
Log(LogLevel.Warning, String.Format("Cannot add peer again: {0}, peer is already added!", ip));
}
else
{
rp = AddPeer(ip);
rp.BeginSend(SendOptions.Reliable, PacketType.AcceptJoin, null, null);
}
}
else if (type == PacketType.AcceptJoin)
{
AwaitingAcceptDetail detail;
if (!TryGetAndRemoveWaitingAcceptDetail(ip, out detail))
{
// Possible reasons we do not have detail are:
// 1) Accept is too late,
// 2) Accept duplicated and we have already removed it, or
// 3) Accept was unsolicited.
Log(LogLevel.Warning, String.Format("Dropped Accept Packet from unknown peer: {0}.", ip));
}
else
{
// create the new peer, add the datagram to send ACK, call the callback
rp = AddPeer(ip);
rp.AddReceivedPacket(seq, opts, type, payload);
TryResult tr = new TryResult(true, null, null, rp.Id);
detail.Callback(tr);
}
}
else
{
Log(LogLevel.Warning, String.Format("Datagram dropped - unknown peer: {0}.", ip));
}
}
else
{
rp.AddReceivedPacket(seq, opts, type, payload);
}
}
catch (SocketException se)
{
// TODO http://msdn.microsoft.com/en-us/library/ms740668.aspx
Log(LogLevel.Error, String.Format("EndReceiveFrom() SocketException: {0}.", se.Message));
}
}
}