public async Task MaxBufferSendWithRandomDrops()
{
SctpDataReceiver receiver = new SctpDataReceiver(1000, 1400, 0);
SctpDataSender sender = new SctpDataSender("dummy", null, 1400, 0, 1000);
sender._burstPeriodMilliseconds = 1;
sender._rtoInitialMilliseconds = 1;
sender._rtoMinimumMilliseconds = 1;
sender.StartSending();
SctpDataFrame frame = SctpDataFrame.Empty;
ManualResetEventSlim frameReady = new ManualResetEventSlim(false);
// This local function replicates a data chunk being sent from a data
// sender to the receiver of a remote peer and the return of the SACK.
Action <SctpDataChunk> doSend = async(chunk) =>
{
if (chunk.SendCount == 1 && Crypto.GetRandomInt(0, 99) % 5 == 0)
{
logger.LogDebug($"Data chunk {chunk.TSN} dropped.");
}
else
{
logger.LogDebug($"Data chunk {chunk.TSN} provided to receiver.");
var frames = receiver.OnDataChunk(chunk);
sender.GotSack(receiver.GetSackChunk());
if (frames.Count > 0)
{
logger.LogDebug($"Receiver got frame of length {frames.First().UserData?.Length}.");
frame = frames.First();
frameReady.Set();
}
}
await Task.Delay(1);
};
sender._sendDataChunk = doSend;
byte[] buffer = new byte[RTCSctpTransport.SCTP_DEFAULT_MAX_MESSAGE_SIZE];
//byte[] buffer = new byte[2000];
Crypto.GetRandomBytes(buffer);
string hash = Crypto.GetSHA256Hash(buffer);
logger.LogDebug($"Max buffer hash {hash}.");
await Task.Delay(50);
sender.SendData(0, 0, buffer);
frameReady.WaitHandle.WaitOne(10000, true);
Assert.False(frame.IsEmpty());
Assert.Equal(buffer.Length, frame.UserData.Length);
Assert.Equal(hash, Crypto.GetSHA256Hash(frame.UserData));
}
public async Task InitialDataChunkDropped()
{
uint arwnd = 131072;
ushort mtu = 1400;
uint initialTSN = Crypto.GetRandomUInt(true);
SctpDataReceiver receiver = new SctpDataReceiver(arwnd, mtu, initialTSN);
SctpDataSender sender = new SctpDataSender("dummy", null, mtu, initialTSN, arwnd);
sender.StartSending();
// This local function replicates a data chunk being sent from a data
// sender to the receiver of a remote peer and the return of the SACK.
Action <SctpDataChunk> doSend = (chunk) =>
{
if (chunk.TSN == initialTSN && chunk.SendCount == 1)
{
logger.LogDebug($"Data chunk {chunk.TSN} dropped.");
}
else
{
receiver.OnDataChunk(chunk);
sender.GotSack(receiver.GetSackChunk());
}
};
sender._sendDataChunk = doSend;
sender.SendData(0, 0, new byte[] { 0x55 });
Assert.Equal(initialTSN + 1, sender.TSN);
await Task.Delay(250);
Assert.Null(receiver.CumulativeAckTSN);
await Task.Delay(500);
sender.SendData(0, 0, new byte[] { 0x55 });
Assert.Equal(initialTSN + 2, sender.TSN);
await Task.Delay(1250);
Assert.Equal(initialTSN + 1, receiver.CumulativeAckTSN);
await Task.Delay(500);
sender.SendData(0, 0, new byte[] { 0x55 });
Assert.Equal(initialTSN + 3, sender.TSN);
await Task.Delay(250);
Assert.Equal(initialTSN + 2, receiver.CumulativeAckTSN);
}
public async Task SACKChunkRetransmit()
{
uint arwnd = 131072;
ushort mtu = 1400;
uint initialTSN = Crypto.GetRandomUInt(true);
SctpDataReceiver receiver = new SctpDataReceiver(arwnd, mtu, initialTSN);
SctpDataSender sender = new SctpDataSender("dummy", null, mtu, initialTSN, arwnd);
sender.StartSending();
// This local function replicates a data chunk being sent from a data
// sender to the receiver of a remote peer and the return of the SACK.
Action <SctpDataChunk> doSend = (chunk) =>
{
receiver.OnDataChunk(chunk);
sender.GotSack(receiver.GetSackChunk());
};
Action <SctpDataChunk> dontSend = (chunk) => { };
sender._sendDataChunk = doSend;
sender.SendData(0, 0, new byte[] { 0x00, 0x01, 0x02 });
Assert.Equal(initialTSN + 1, sender.TSN);
await Task.Delay(250);
Assert.Equal(initialTSN, receiver.CumulativeAckTSN);
// This send to the receiver is blocked so the receivers ACK TSN should stay the same.
sender._sendDataChunk = dontSend;
sender.SendData(0, 0, new byte[] { 0x00, 0x01, 0x02 });
Assert.Equal(initialTSN + 2, sender.TSN);
await Task.Delay(250);
Assert.Equal(initialTSN, receiver.CumulativeAckTSN);
// Unblock. Receiver's ACK TSN should not advance as it has a missing chunk.
sender._sendDataChunk = doSend;
sender.SendData(0, 0, new byte[] { 0x00, 0x01, 0x02 });
Assert.Equal(initialTSN + 3, sender.TSN);
await Task.Delay(250);
Assert.Equal(initialTSN + 2, receiver.CumulativeAckTSN);
}
public void MaxBufferSend()
{
uint arwnd = SctpAssociation.DEFAULT_ADVERTISED_RECEIVE_WINDOW;
SctpDataReceiver receiver = new SctpDataReceiver(arwnd, 1400, 0);
SctpDataSender sender = new SctpDataSender("dummy", null, 1400, 0, arwnd);
sender.StartSending();
SctpDataFrame frame = SctpDataFrame.Empty;
ManualResetEventSlim frameReady = new ManualResetEventSlim(false);
// This local function replicates a data chunk being sent from a data
// sender to the receiver of a remote peer and the return of the SACK.
Action <SctpDataChunk> doSend = (chunk) =>
{
logger.LogDebug($"Data chunk {chunk.TSN} provided to receiver.");
var frames = receiver.OnDataChunk(chunk);
sender.GotSack(receiver.GetSackChunk());
if (frames.Count > 0)
{
logger.LogDebug($"Receiver got frame of length {frames.First().UserData?.Length}.");
frame = frames.First();
frameReady.Set();
}
};
sender._sendDataChunk = doSend;
byte[] buffer = new byte[RTCSctpTransport.SCTP_DEFAULT_MAX_MESSAGE_SIZE];
Crypto.GetRandomBytes(buffer);
string hash = Crypto.GetSHA256Hash(buffer);
logger.LogDebug($"Max buffer hash {hash}.");
sender.SendData(0, 0, buffer);
frameReady.WaitHandle.WaitOne(10000, true);
Assert.False(frame.IsEmpty());
Assert.Equal(RTCSctpTransport.SCTP_DEFAULT_MAX_MESSAGE_SIZE, (uint)frame.UserData.Length);
Assert.Equal(hash, Crypto.GetSHA256Hash(frame.UserData));
}
public void MediumBufferSend()
{
ushort mtu = 1400;
SctpDataReceiver receiver = new SctpDataReceiver(1000, mtu, 0);
SctpDataSender sender = new SctpDataSender("dummy", null, mtu, 0, 1000);
sender.StartSending();
SctpDataFrame frame = SctpDataFrame.Empty;
ManualResetEventSlim frameReady = new ManualResetEventSlim(false);
// This local function replicates a data chunk being sent from a data
// sender to the receiver of a remote peer and the return of the SACK.
Action <SctpDataChunk> doSend = (chunk) =>
{
logger.LogDebug($"Data chunk {chunk.TSN} provided to receiver.");
var frames = receiver.OnDataChunk(chunk);
sender.GotSack(receiver.GetSackChunk());
if (frames.Count > 0)
{
logger.LogDebug($"Receiver got frame of length {frames.First().UserData?.Length}.");
frame = frames.First();
frameReady.Set();
}
};
sender._sendDataChunk = doSend;
byte[] buffer = new byte[10 * mtu];
Crypto.GetRandomBytes(buffer);
string hash = Crypto.GetSHA256Hash(buffer);
logger.LogDebug($"Medium buffer hash {hash}.");
sender.SendData(0, 0, buffer);
frameReady.WaitHandle.WaitOne(5000, true);
Assert.False(frame.IsEmpty());
Assert.Equal(buffer.Length, frame.UserData.Length);
Assert.Equal(hash, Crypto.GetSHA256Hash(frame.UserData));
}
public async Task IncreaseCongestionWindowSlowStart()
{
uint arwnd = SctpAssociation.DEFAULT_ADVERTISED_RECEIVE_WINDOW;
ushort mtu = 1400;
uint initialTSN = 0;
SctpDataReceiver receiver = new SctpDataReceiver(arwnd, mtu, initialTSN);
SctpDataSender sender = new SctpDataSender("dummy", null, mtu, initialTSN, arwnd);
sender._burstPeriodMilliseconds = 1;
sender._rtoInitialMilliseconds = 1;
sender._rtoMinimumMilliseconds = 1;
Action <SctpDataChunk> reluctantSender = (chunk) =>
{
if (chunk.TSN % 10 == 0)
{
receiver.OnDataChunk(chunk);
sender.GotSack(receiver.GetSackChunk());
}
};
sender._sendDataChunk = reluctantSender;
sender.StartSending();
Assert.Equal(SctpDataSender.CONGESTION_WINDOW_FACTOR, sender._congestionWindow);
var buffer = new byte[mtu];
for (int i = 0; i <= 10; i++)
{
sender.SendData(0, 0, buffer);
}
await Task.Delay(500);
Assert.Equal(SctpDataSender.CONGESTION_WINDOW_FACTOR + mtu, sender._congestionWindow);
}