/// <summary>
/// Tests the reliablity components of the underlying protocol. In order to do that,
/// we need to simulate sending a number of packets in-order, out of order, in-time
/// and out of time (to simulate dropped packets). This is an extremly granular test
/// of the packets themselves, a seperate message reliabilty test exists to ensure
/// that pipes receive their data and congestion control does its job or resending
/// unacked packets.
///
/// The concrete congestion tests will set up two controller mocks and pass them into
/// this function which will simulate communications between the two points. This function
/// assumes that all of the objects have been correctly
/// </summary>
/// <param name="ep1">Ep1.</param>
/// <param name="ep2">Ep2.</param>
/// <param name="maxTimeoutPerPacket">A maximum timeout per packet
/// before packetloss is deemed a failure</param>
internal void TestReliablityAtomic(TunnelCongestionControllerMock ep1,
TunnelCongestionControllerMock ep2,
Int32 maxTimeOutPerPacket)
{
Assert.IsNotNull(mPs1, "You must set ep1 to use mPs1 as its packet sender");
Assert.IsNotNull(mPs2, "You must set ep2 to use mPs2 as its packet sender");
GenericPacketMock p1 = new GenericPacketMock(1);
GenericPacketMock p2 = new GenericPacketMock(2);
GenericPacketMock p3 = new GenericPacketMock(3);
GenericPacketMock p4 = new GenericPacketMock(4);
Queue <int> expectedAcks = new Queue <int> ();
for (int i = 1; i <= 4; i++)
{
expectedAcks.Enqueue(i);
}
//the test sends packets from ep1 to ep2
int curCount = 1;
mPs1.InterceptOutgoingPacket(p => {
//ensure that the acks come in order
ep2.HandleIncomingPacket(p);
});
mPs2.InterceptOutgoingPacket(p => {
ep1.HandleIncomingPacket(p);
Assert.IsTrue(expectedAcks.Dequeue() == p.Ack, "Failed at packet seq" + p.Ack);
});
ep1.SendPacket(p1);
ep1.SendPacket(p2);
ep1.SendPacket(p4);
ep1.SendPacket(p3);
}
/// <summary>
/// This test launches multiple tests and sends a series of packets through an object
/// that simulates packet loss. The packet loss will medium will randomly simulate
/// RTT delays, MTU size differences and just packet loss.
/// </summary>
internal void TestReliability(TunnelCongestionControllerMock ep1,
TunnelSocketSendIntercept sock1,
TunnelCongestionControllerMock ep2,
TunnelSocketSendIntercept sock2,
int lossPercentage,
UInt32 dgramSize)
{
LossyConnection connection = new LossyConnection(lossPercentage);
//hook ep1 to ep2
//sending from ep1 to ep2
sock1.SetSendInterceptor(p =>
{
//outgoing packet needs to be bubbled into sock2
connection.SendPacket(p, ep2);
});
//ep2 sends an ack to ep1
sock2.SetSendInterceptor(p =>
{
//add test for acks (they should always come in order)
connection.SendPacket(p, ep1);
});
int curAck = 1;
ep1.SetIncomingPacketInterceptor(p =>
{
//should receive Ack's in order
Assert.IsTrue(curAck == p.Ack, "Acks should be received in order");
});
StringBuilder buildString = new StringBuilder();
ep2.SetIncomingPacketInterceptor(p =>
{
GenericPacketMock gp = (GenericPacketMock)p;
buildString.Append(Encoding.ASCII.GetString(gp.GetPayload()));
});
//the test executes on a seperate thread
Thread testThread = new Thread(new ThreadStart(() =>
{
byte[] txt = Encoding.ASCII.GetBytes(this.sendText);
int size = 576 - 8 - 80;
uint seq = 1;
ArrayList <GenericPacketMock> packets = new ArrayList <GenericPacketMock>();
int numPackets = txt.Length / size;
int overFlow = txt.Length % size;
if (overFlow > 0)
{
numPackets += 1;
}
for (int i = 0; i < numPackets; i++)
{
int sizeSubArray = Math.Min(size, txt.Length - (i * size));
byte[] sub = new byte[sizeSubArray];
Array.Copy(txt, i * size, sub, 0, sizeSubArray);
GenericPacketMock p = new GenericPacketMock(seq);
p.SetPayload(sub);
seq++;
packets.Add(p);
}
foreach (GenericPacket p in packets)
{
ep1.SendPacket(p);
}
}));
testThread.Start();
Thread.Sleep(1000);
Assert.IsTrue(this.sendText.Equals(buildString.ToString()), buildString.ToString());
}