private bool CheckSessionId(ref PacketReader reader, TPeer source)
{
var session = reader.ReadUInt32();
if (session != _sessionId)
{
Log.Warn("Received a packet with incorrect session ID. Expected {0}, got {1}. Resetting client.", _sessionId, session);
//Send back a packet forcing this client to disconnect. The client may reconnect, in which case it will re-run the entire handshake and acquire the correct session ID.
var writer = new PacketWriter(new byte[7]);
writer.WriteErrorWrongSession(_sessionId);
SendUnreliable(source, writer.Written);
return(false);
}
return(true);
}
private ushort?ProcessReceivedPacket(ArraySegment <byte> data)
{
var reader = new PacketReader(data);
MessageTypes header;
if (!reader.ReadPacketHeader(out header))
{
Log.Warn("Discarding packet - incorrect magic number.");
return(null);
}
Log.Trace("Received Packet type: {0}", header);
switch (header)
{
case MessageTypes.VoiceData:
if (CheckSessionId(ref reader, header))
{
_voiceReceiver.ReceiveVoiceData(ref reader);
_recvVoiceData.Update(reader.Read.Count);
}
break;
case MessageTypes.TextData:
if (CheckSessionId(ref reader, header))
{
_textReceiver.ProcessTextMessage(ref reader);
_recvTextData.Update(reader.Read.Count);
}
break;
case MessageTypes.HandshakeResponse:
_serverNegotiator.ReceiveHandshakeResponseHeader(ref reader);
_peers.ReceiveHandshakeResponseBody(ref reader);
_recvHandshakeResponse.Update(reader.Read.Count);
if (_serverNegotiator.LocalId.HasValue)
{
OnServerAssignedSessionId(_serverNegotiator.SessionId, _serverNegotiator.LocalId.Value);
}
break;
case MessageTypes.RemoveClient:
if (CheckSessionId(ref reader, header))
{
_peers.ProcessRemoveClient(ref reader);
_recvRemoveClient.Update(reader.Read.Count);
}
break;
case MessageTypes.ClientState:
if (CheckSessionId(ref reader, header))
{
_peers.ProcessClientState(null, ref reader);
_recvClientState.Update(reader.Read.Count);
}
break;
case MessageTypes.DeltaChannelState:
if (CheckSessionId(ref reader, header))
{
_peers.ProcessDeltaChannelState(ref reader);
_recvDeltaState.Update(reader.Read.Count);
}
break;
case MessageTypes.ErrorWrongSession:
{
var session = reader.ReadUInt32();
if (_serverNegotiator.SessionId != session)
{
FatalError(string.Format("Kicked from session - wrong session ID. Mine:{0} Theirs:{1}", _serverNegotiator.SessionId, session));
}
}
break;
case MessageTypes.HandshakeP2P:
if (CheckSessionId(ref reader, header))
{
ushort id;
reader.ReadhandshakeP2P(out id);
_recvHandshakeP2P.Update(reader.Read.Count);
return(id);
}
break;
case MessageTypes.ServerRelayReliable:
case MessageTypes.ServerRelayUnreliable:
case MessageTypes.HandshakeRequest:
Log.Error("Client received packet '{0}'. This should only ever be received by the server", header);
break;
default:
Log.Debug("Ignoring a packet with an unknown header: '{0}'", header);
break;
}
return(null);
}
/// <summary>
/// Receive a packet from the network for dissonance
/// </summary>
/// <param name="source">An integer identifying where this packet came from (same ID will be used for sending)</param>
/// <param name="data">Packet received</param>
public void NetworkReceivedPacket(TPeer source, ArraySegment <byte> data)
{
var reader = new PacketReader(data);
var magic = reader.ReadUInt16();
if (magic != PacketWriter.Magic)
{
Log.Warn("Received packet with incorrect magic number. Expected {0}, got {1}", PacketWriter.Magic, magic);
return;
}
var header = (MessageTypes)reader.ReadByte();
if (header != MessageTypes.HandshakeRequest)
{
var session = reader.ReadUInt32();
if (session != _sessionId)
{
Log.Warn("Received a packet with incorrect session ID. Expected {0}, got {1}. Resetting client.", _sessionId, session);
SendErrorWrongSession(source, _sessionId);
return;
}
}
switch (header)
{
case MessageTypes.ClientState:
RecvClientState.Update(data.Count);
_clients.ProcessClientState(source, ref reader);
break;
case MessageTypes.PlayerRoutingUpdate:
Log.Error("Received a routing update (this should only ever be received by the client)");
break;
case MessageTypes.VoiceData:
RecvVoiceData.Update(data.Count);
_packetRouter.ProcessVoiceData(source, ref reader);
break;
case MessageTypes.TextData:
RecvTextData.Update(data.Count);
_packetRouter.ProcessTextData(ref reader);
break;
case MessageTypes.HandshakeRequest:
RecvHandshakeRequest.Update(data.Count);
ClientDisconnected(source); // disconnect existing peers on this connection
((IServer <TPeer>) this).SendReliable(source, _handshakeResponse);
break;
case MessageTypes.HandshakeResponse:
Log.Error("Received a handshake response (this should only ever be received by the client)");
break;
case MessageTypes.ErrorWrongSession:
Log.Error("Received wrong session error from client (this should only ever be received by the client)");
break;
default:
Log.Error("Ignoring a packet with an unknown header: '{0}'", header);
break;
}
}
