// note: original HLAPI HandleBytes function handled >1 message in a while loop, but this wasn't necessary
// anymore because NetworkServer/NetworkClient Update both use while loops to handle >1 data events per
// frame already.
// -> in other words, we always receive 1 message per Receive call, never two.
// -> can be tested easily with a 1000ms send delay and then logging amount received in while loops here
// and in NetworkServer/Client Update. HandleBytes already takes exactly one.
/// <summary>
/// This function allows custom network connection classes to process data from the network before it is passed to the application.
/// </summary>
/// <param name="buffer">The data received.</param>
internal void TransportReceive(ArraySegment <byte> buffer, int channelId)
{
// unpack message
using (PooledNetworkReader networkReader = NetworkReaderPool.GetReader(buffer))
{
try
{
int msgType = MessagePacker.UnpackId(networkReader);
if (msgType == MessagePacker.GetId <NotifyPacket>())
{
// this is a notify message, send to the notify receive
NotifyPacket notifyPacket = networkReader.ReadNotifyPacket();
ReceiveNotify(notifyPacket, networkReader, channelId);
}
else
{
// try to invoke the handler for that message
InvokeHandler(msgType, networkReader, channelId);
}
}
catch (InvalidDataException ex)
{
logger.Log(ex.ToString());
}
catch (Exception ex)
{
logger.LogError("Closed connection: " + this + ". Invalid message " + ex);
Connection?.Disconnect();
}
}
}
public void HandleMessage(INetworkPlayer player, ArraySegment <byte> packet)
{
using (PooledNetworkReader networkReader = NetworkReaderPool.GetReader(packet))
{
// set ObjectLocator so that message can use NetworkIdentity
networkReader.ObjectLocator = objectLocator;
// protect against attackers trying to send invalid data packets
// exception could be throw if:
// - invalid headers
// - invalid message ids
// - invalid data causing exceptions
// - negative ReadBytesAndSize prefixes
// - invalid utf8 strings
// - etc.
//
// if exception is caught, disconnect the attacker to stop any further attacks
try
{
int msgType = MessagePacker.UnpackId(networkReader);
InvokeHandler(player, msgType, networkReader);
}
catch (Exception e)
{
string disconnectMessage = disconnectOnException ? $", Closed connection: {player}" : "";
logger.LogError($"{e.GetType()} in Message handler (see stack below){disconnectMessage}\n{e}");
if (disconnectOnException)
{
player.Disconnect();
}
}
}
}
internal void ReceiveNotify(NotifyPacket notifyPacket, NetworkReader networkReader, int channelId)
{
int sequenceDistance = (int)sequencer.Distance(notifyPacket.Sequence, receiveSequence);
// sequence is so far out of bounds we can't save, just kick him (or her!)
if (Math.Abs(sequenceDistance) > WINDOW_SIZE)
{
connection?.Disconnect();
return;
}
// this message is old, we already received
// a newer or duplicate packet. Discard it
if (sequenceDistance <= 0)
{
return;
}
receiveSequence = notifyPacket.Sequence;
if (sequenceDistance >= ACK_MASK_BITS)
{
receiveMask = 1;
}
else
{
receiveMask = (receiveMask << sequenceDistance) | 1;
}
AckPackets(notifyPacket.ReceiveSequence, notifyPacket.AckMask);
int msgType = MessagePacker.UnpackId(networkReader);
InvokeHandler(msgType, networkReader, channelId);
if (Time.unscaledTime - lastNotifySentTime > NOTIFY_ACK_TIMEOUT)
{
SendNotify(new NotifyAck(), null, channelId);
}
}