/// <summary>
/// generates new pow2request object
/// resets state when necessary
/// </summary>
public Pow2RequestState GenerateOrGetExistingPow2(IPEndPoint requesterEndpoint)
{
var timeNowRel = TimeNowRel;
if (timeNowRel > _nextPeriodSwitchTimeRel || _currentPeriodStates.Count > _config.Pow2RequestStatesTableMaxSize)
{ // switch tables
_previousPeriodStates = _currentPeriodStates;
_currentPeriodStates = new Dictionary <IPEndPoint, Pow2RequestState>();
_nextPeriodSwitchTimeRel = timeNowRel + _config.Pow2RequestStatesTablePeriod;
}
var existingPow2RequestState = TryGetPow2RequestState(requesterEndpoint);
if (existingPow2RequestState != null)
{
return(existingPow2RequestState);
}
var r = new Pow2RequestState
{
ProofOfWork2Request = new byte[16]
};
_rnd.NextBytes(r.ProofOfWork2Request);
_currentPeriodStates.Add(requesterEndpoint, r);
return(r);
}
/// <summary>
/// is executed by receiver thread
/// </summary>
void ProcessRegisterReqAtoEpPacket(IPEndPoint requesterEndpoint, byte[] udpData, Stopwatch reqReceivedAtSW)
{
Pow2RequestState pow2RequestState = null;
if (!Configuration.SandboxModeOnly_DisablePoW)
{
pow2RequestState = _pow2RequestsTable.TryGetPow2RequestState(requesterEndpoint);
if (pow2RequestState == null)
{
OnReceivedRegisterReqAtoEpPacketFromUnknownSource(requesterEndpoint);
return;
}
}
var req = RegisterRequestPacket.Decode_OptionallyVerifyNeighborHMAC(udpData, null, Configuration.SandboxModeOnly_NumberOfDimensions);
if (!Configuration.SandboxModeOnly_DisablePoW)
{
if (!Pow2IsOK(req, pow2RequestState.ProofOfWork2Request))
{
OnReceivedRegisterReqAtoEpPacketWithBadPow2(requesterEndpoint);
// intentionally we dont respond to requester, in case if it is attack
return;
}
}
EngineThreadQueue.Enqueue(() =>
{
_ = ProcessRegisterReqAtoEpPacket2Async(requesterEndpoint, req, reqReceivedAtSW);
}, "ProcessRegisterReqAtoEpPacket2Async436");
}
