internal static int CalculateOffset(double now, ushort val, double roundtrip)
{
int oneWayMillis = (int)(roundtrip * 500.0);
int remoteNow = NormalizeEncoded(val + oneWayMillis);
int localNow = NetTime.Encoded(now);
return(remoteNow - localNow);
}
/// <summary>
/// Returns absolute timestamp
/// Note; will only accept encoded timestamps IN THE PAST
/// </summary>
public static float FromEncoded(float now, int remoteMillisOffset, ushort encodedRemoteTimestamp, out int adjustRemoteMillis)
{
// my encoded time
ushort localNow = (ushort)(now * 1000 % ushort.MaxValue);
ushort localStamp = NetTime.NormalizeEncoded(encodedRemoteTimestamp - remoteMillisOffset);
int elapsedMillis = NetTime.GetElapsedMillis(localStamp, localNow);
adjustRemoteMillis = 0;
return(now - ((float)elapsedMillis / 1000.0f));
}
internal static int SendConnectResponse(NetBase netBase, NetConnection clientConnection, IPEndPoint remoteEndpoint)
{
double now = NetTime.Now;
ushort nowEnc = NetTime.Encoded(now);
NetMessage response = new NetMessage(NetMessageType.Handshake, 3);
response.Write((byte)NetHandshakeType.ConnectResponse);
response.Write(nowEnc);
clientConnection.m_firstSentHandshake = now;
clientConnection.m_lastSentHandshake = now;
return(netBase.SendSingleMessageAtOnce(response, clientConnection, remoteEndpoint));
}
/// <summary>
/// Reads a timestamp written using WriteSendStamp()
/// </summary>
public double ReadSentStamp(NetConnection connection)
{
if (connection == null)
{
throw new ArgumentNullException("connection");
}
ushort val = m_buffer.ReadUInt16();
int adjustRemoteMillis;
float retval = NetTime.FromEncoded((float)NetTime.Now, connection.RemoteClockOffset, val, out adjustRemoteMillis);
//if (adjustRemoteMillis != 0)
// connection.RemoteClockOffset = (connection.RemoteClockOffset + adjustRemoteMillis) % ushort.MaxValue;
return(retval);
}
internal void HandlePong(double now, NetMessage pongMessage)
{
int nr = pongMessage.ReadByte(6);
if (nr != m_pingNrInProgress)
{
m_connection.Parent.Log.Warning("Pong received for wrong ping; received " + nr + " expecting " + m_pingNrInProgress);
return;
}
double roundtrip = now - m_lastSentPing;
// spike, or can we use this roundtrip?
double avgRT = pongMessage.Sender.AverageRoundtripTime;
if (roundtrip > avgRT * 2.0)
{
// must be spike
m_connection.Parent.Log.Verbose("Not adjusting clock due lag spike... (rt " + NetUtil.SecToMil(roundtrip) + " avg " + NetUtil.SecToMil(avgRT) + ")");
}
else
{
ushort val = pongMessage.ReadUInt16();
int curOffset = m_connection.RemoteClockOffset;
int foundOffset = NetTime.CalculateOffset(now, val, roundtrip);
int res = NetTime.MergeOffsets(curOffset, foundOffset);
int rtMillis = (int)(roundtrip * 1000.0);
if (res != curOffset)
{
//m_connection.Parent.Log.Verbose("Ping: " + rtMillis + " Local: " + NetTime.Encoded(now) + " CurOffset: " + curOffset + " Remote: " + val + " NewOffset: " + res + " (adjusted " + (res - curOffset) + ")");
m_connection.Parent.Log.Verbose("Roundtrip: " + rtMillis + " ms; Ajusted remote offset " + (res - curOffset) + " ms");
m_connection.RemoteClockOffset = res;
}
}
AddRoundtrip((float)roundtrip);
if (m_connection.Parent is NetServer)
{
// server is authorative on settings optimizing roundtrip numbers
m_connection.Configuration.OptimizeSettings(m_averageRoundtrip);
SendOptimizeInfo(m_averageRoundtrip);
}
return;
}
internal override void HandlePacket(NetBuffer buffer, int bytesReceived, IPEndPoint senderEndpoint)
{
double now = NetTime.Now;
NetConnection sender = FindConnection(senderEndpoint);
if (sender != null)
{
sender.m_lastHeardFromRemote = now;
if (sender.m_encryption.SymmetricEncryptionKeyBytes != null)
{
bool ok = sender.m_encryption.DecryptSymmetric(buffer);
if (!ok)
{
Log.Warning("Failed to decrypt packet from client " + sender);
return;
}
}
}
try
{
NetMessage response;
int messagesReceived = 0;
int usrMessagesReceived = 0;
int ackMessagesReceived = 0;
while (buffer.ReadBitsLeft > 7)
{
NetMessage msg = NetMessage.Decode(buffer);
if (msg == null)
{
break; // done
}
messagesReceived++;
msg.Sender = sender;
switch (msg.m_type)
{
case NetMessageType.Acknowledge:
case NetMessageType.AcknowledgeBitField:
if (sender == null)
{
Log.Warning("Received Ack from not-connected source!");
}
else
{
//Log.Debug("Received ack " + msg.SequenceChannel + "|" + msg.SequenceNumber);
sender.ReceiveAcknowledge(msg);
ackMessagesReceived++;
}
break;
case NetMessageType.Handshake:
NetHandshakeType tp = (NetHandshakeType)msg.ReadByte();
if (tp == NetHandshakeType.ConnectResponse)
{
Log.Warning("Received ConnectResponse?!");
}
else if (tp == NetHandshakeType.Connect)
{
if (sender == null)
{
NetHandshake.HandleConnect(msg, this, senderEndpoint);
}
else
{
// resend response
NetHandshake.SendConnectResponse(this, sender, senderEndpoint);
Log.Verbose("Redundant Connect received; resending response");
}
}
else if (tp == NetHandshakeType.ConnectionEstablished)
{
if (sender == null)
{
Log.Warning("Received ConnectionEstablished, but no sender connection?!");
}
else
{
float rt = (float)(now - sender.m_firstSentHandshake);
sender.m_ping.Initialize(rt);
ushort remoteValue = msg.ReadUInt16();
sender.RemoteClockOffset = NetTime.CalculateOffset(now, remoteValue, rt);
Log.Verbose("Reinitializing remote clock offset to " + sender.RemoteClockOffset + " ms (roundtrip " + NetUtil.SecToMil(rt) + " ms)");
if (sender.Status == NetConnectionStatus.Connected)
{
Log.Verbose("Redundant ConnectionEstablished received");
}
else
{
Log.Debug("Connection established");
sender.SetStatus(NetConnectionStatus.Connected, "Connected by established");
}
}
}
else
{
// disconnected
if (sender == null)
{
Log.Warning("Disconnected received from unconnected source: " + senderEndpoint);
return;
}
string reason = msg.ReadString();
sender.Disconnected(reason);
}
break;
case NetMessageType.Discovery:
Log.Debug("Answering discovery response from " + senderEndpoint);
response = NetDiscovery.EncodeResponse(this);
SendSingleMessageAtOnce(response, null, senderEndpoint);
break;
case NetMessageType.PingPong:
if (sender == null)
{
return;
}
bool isPong = msg.ReadBoolean();
bool isOptimizeInfo = msg.ReadBoolean();
if (isOptimizeInfo)
{
// DON'T handle optimizeinfo... only clients should adapt to server ping info
}
else if (isPong)
{
if (sender.Status == NetConnectionStatus.Connected)
{
sender.m_ping.HandlePong(now, msg);
}
}
else
{
NetPing.ReplyPong(msg, sender); // send pong
}
break;
case NetMessageType.User:
case NetMessageType.UserFragmented:
usrMessagesReceived++;
if (sender == null)
{
Log.Warning("User message received from unconnected source: " + senderEndpoint);
return; // don't handle user messages from unconnected sources
}
if (sender.Status == NetConnectionStatus.Connecting)
{
sender.SetStatus(NetConnectionStatus.Connected, "Connected by user message");
}
sender.ReceiveMessage(now, msg);
break;
default:
Log.Warning("Bad message type: " + msg);
break;
}
}
if (sender != null)
{
NetStatistics stats = sender.Statistics;
stats.PacketsReceived++;
stats.MessagesReceived += messagesReceived;
stats.UserMessagesReceived += usrMessagesReceived;
stats.AckMessagesReceived += ackMessagesReceived;
stats.BytesReceived += bytesReceived;
}
}
catch (Exception ex)
{
Log.Error("Failed to parse packet correctly; read/write mismatch? " + ex);
}
}
internal override void HandlePacket(NetBuffer buffer, int bytesReceived, IPEndPoint sender)
{
double now = NetTime.Now;
try
{
NetMessage msg;
if (m_serverConnection == null || m_serverConnection.Status == NetConnectionStatus.Disconnected)
{
//
// unconnected packet
//
msg = NetMessage.Decode(buffer);
if (msg == null)
{
Log.Warning("Malformed NetMessage?");
return; // malformed?
}
Log.Verbose("Received unconnected message: " + msg);
// discovery response?
if (msg.m_type == NetMessageType.Discovery)
{
NetServerInfo info = NetDiscovery.DecodeResponse(msg, sender);
if (ServerDiscovered != null)
{
ServerDiscovered(this, new NetServerDiscoveredEventArgs(info));
}
return;
}
if (m_serverConnection != null && sender.Equals(m_serverConnection.RemoteEndpoint))
{
// we have m_serverConnection, but status is disconnected
Log.Warning("Received " + buffer.LengthBytes + " from server; but we're disconnected!");
return;
}
Log.Warning("Received " + buffer.LengthBytes + " bytes from non-server source: " + sender + "(server is " + m_serverConnection.RemoteEndpoint + ")");
return;
}
// decrypt in place
if (m_serverConnection.m_encryption.SymmetricEncryptionKeyBytes != null)
{
byte[] savedBuffer = null;
if (m_serverConnection.Status == NetConnectionStatus.Connecting)
{
// special case; save buffer in case we get unencrypted response
savedBuffer = new byte[buffer.LengthBytes];
Array.Copy(buffer.Data, 0, savedBuffer, 0, buffer.LengthBytes);
}
bool ok = m_serverConnection.m_encryption.DecryptSymmetric(buffer);
if (!ok)
{
// failed to decrypt; drop this packet UNLESS we're in a connecting state,
// in which case the server may want to tell us something
if (m_serverConnection.Status == NetConnectionStatus.Connecting)
{
// ok let this one thru unencrypted
Array.Copy(savedBuffer, buffer.Data, savedBuffer.Length);
}
else
{
Log.Warning("Failed to decrypt packet from server!");
return;
}
}
}
m_serverConnection.m_lastHeardFromRemote = now;
int messagesReceived = 0;
int usrMessagesReceived = 0;
int ackMessagesReceived = 0;
while (buffer.ReadBitsLeft > 7)
{
msg = NetMessage.Decode(buffer);
if (msg == null)
{
break; // done
}
messagesReceived++;
msg.Sender = m_serverConnection;
switch (msg.m_type)
{
case NetMessageType.Handshake:
NetHandshakeType tp = (NetHandshakeType)msg.ReadByte();
if (tp == NetHandshakeType.Connect || tp == NetHandshakeType.ConnectionEstablished)
{
Log.Warning("Client received " + tp + "?!");
}
else if (tp == NetHandshakeType.ConnectResponse)
{
if (m_serverConnection.Status != NetConnectionStatus.Connecting)
{
Log.Verbose("Received redundant ConnectResponse!");
break;
}
// Log.Debug("ConnectResponse received");
m_serverConnection.SetStatus(NetConnectionStatus.Connected, "Connected");
Log.Info("Connected to " + m_serverConnection.RemoteEndpoint);
// initialize ping to now - m_firstSentConnect
float initRoundtrip = (float)(now - m_serverConnection.m_firstSentHandshake);
m_serverConnection.m_ping.Initialize(initRoundtrip);
ushort remoteValue = msg.ReadUInt16();
m_serverConnection.RemoteClockOffset = NetTime.CalculateOffset(now, remoteValue, initRoundtrip);
Log.Verbose("Initializing remote clock offset to " + m_serverConnection.RemoteClockOffset + " ms (roundtrip " + NetUtil.SecToMil(initRoundtrip) + " ms)");
NetMessage established = new NetMessage(NetMessageType.Handshake, 3);
established.Write((byte)NetHandshakeType.ConnectionEstablished);
established.WriteSendStamp();
SendSingleMessageAtOnce(established, m_serverConnection, m_serverConnection.RemoteEndpoint);
}
else
{ // Disconnected
string reason = msg.ReadString();
m_serverConnection.SetStatus(NetConnectionStatus.Disconnected, reason);
}
break;
case NetMessageType.Acknowledge:
//Log.Debug("Received ack " + msg.SequenceChannel + "|" + msg.SequenceNumber);
m_serverConnection.ReceiveAcknowledge(msg);
ackMessagesReceived++;
break;
case NetMessageType.PingPong:
bool isPong = msg.ReadBoolean();
bool isOptimizeInfo = msg.ReadBoolean();
if (isOptimizeInfo)
{
m_serverConnection.m_ping.HandleOptimizeInfo(now, msg);
}
else if (isPong)
{
if (m_serverConnection.Status == NetConnectionStatus.Connected)
{
m_serverConnection.m_ping.HandlePong(now, msg);
}
}
else
{
NetPing.ReplyPong(msg, m_serverConnection);
}
break;
case NetMessageType.User:
case NetMessageType.UserFragmented:
//Log.Debug("User message received; " + msg.m_buffer.LengthBytes + " bytes");
m_serverConnection.ReceiveMessage(now, msg);
usrMessagesReceived++;
break;
case NetMessageType.Discovery:
NetServerInfo info = NetDiscovery.DecodeResponse(msg, sender);
if (ServerDiscovered != null)
{
ServerDiscovered(this, new NetServerDiscoveredEventArgs(info));
}
break;
default:
Log.Warning("Client received " + msg.m_type + "?!");
break;
}
}
// add statistics
NetStatistics stats = m_serverConnection.Statistics;
stats.PacketsReceived++;
stats.MessagesReceived += messagesReceived;
stats.UserMessagesReceived += usrMessagesReceived;
stats.AckMessagesReceived += ackMessagesReceived;
stats.BytesReceived += bytesReceived;
}
catch (Exception ex)
{
Log.Error("Failed to parse packet correctly; read/write mismatch? " + ex);
}
}
/// <summary>
/// Write a timestamp IN THE PAST
/// </summary>
public void WriteSendStamp(double pastTimestamp)
{
m_buffer.Write(NetTime.Encoded(pastTimestamp));
}
internal static void HandleConnect(NetMessage connectMsg, NetServer server, IPEndPoint senderEndpoint)
{
NetMessage response;
if (server.NumConnected >= server.Configuration.MaximumConnections)
{
// server full
response = new NetMessage(NetMessageType.Handshake, "Server full".Length + 1);
response.Write((byte)NetHandshakeType.Disconnected);
response.Write("Server full");
server.SendSingleMessageAtOnce(response, null, senderEndpoint);
return;
}
ushort remoteNow = connectMsg.ReadUInt16();
//server.Log.Debug("Setting remote clock based on guess of 50 ms lag...");
int remoteClockOffset = NetTime.CalculateOffset(NetTime.Now, remoteNow, 0.05); // assume 50ms...
// read symmetric key
int encSymKeyLen = connectMsg.ReadUInt16();
byte[] encSymKey = null;
if (encSymKeyLen > 0)
{
encSymKey = connectMsg.ReadBytes(encSymKeyLen);
}
// read custom data
int cdLen = (int)connectMsg.Read7BitEncodedUInt();
byte[] customData = null;
if (cdLen > 0)
{
customData = connectMsg.ReadBytes(cdLen);
}
string failReason = null;
bool ok = server.ApproveConnection(senderEndpoint, customData, out failReason);
if (!ok)
{
if (!string.IsNullOrEmpty(failReason))
{
// send disconnect reason; unencrypted, client can handle it because status is connecting
response = new NetMessage(NetMessageType.Handshake, failReason.Length + 3);
response.Write((byte)NetHandshakeType.Disconnected);
response.Write(failReason);
server.SendSingleMessageAtOnce(response, null, senderEndpoint);
}
// connection not approved
return;
}
NetConnection connection = server.AddConnection(senderEndpoint, remoteClockOffset);
if (connection == null)
{
return; // uh oh
}
if (encSymKeyLen > 0)
{
byte[] symKey = connection.m_encryption.DecryptRSA(encSymKey);
if (symKey == null)
{
// send disconnect unencrypted, client can handle it because status is connecting
string bye = "RSA failed; are you using correct public key?";
response = new NetMessage(NetMessageType.Handshake, bye.Length + 3);
response.Write((byte)NetHandshakeType.Disconnected);
response.Write(bye);
server.SendSingleMessageAtOnce(response, null, senderEndpoint);
server.Log.Warning("Failed to decrypt RSA encrypted symmetric key from " + senderEndpoint);
return;
}
connection.m_encryption.SetSymmetricKey(symKey);
server.Log.Debug("Received Connect containing key: " + Convert.ToBase64String(symKey));
}
else
{
if (server.Configuration.UsesEncryption)
{
server.Log.Warning("Client tried to connect without encryption from " + senderEndpoint);
// denied
response = new NetMessage(NetMessageType.Handshake, "Encryption required".Length + 1);
response.Write((byte)NetHandshakeType.Disconnected);
response.Write("Encryption required");
server.SendSingleMessageAtOnce(response, null, senderEndpoint);
return;
}
server.Log.Debug("Received Connect - using unencrypted connection!");
}
// send connect response
int bytesSent = SendConnectResponse(server, connection, senderEndpoint);
if (connection != null)
{
// account for connectresponse
connection.Statistics.PacketsSent++;
connection.Statistics.MessagesSent++;
connection.Statistics.BytesSent += bytesSent;
}
}