// does not reach here.
/// <summary>
/// The contract is similar to
/// <see cref="SocketChannel.Connect(System.Net.EndPoint)"/>
///
/// with a timeout.
/// </summary>
/// <seealso cref="SocketChannel.Connect(System.Net.EndPoint)"/>
/// <param name="channel">
/// - this should be a
/// <see cref="SelectableChannel"/>
/// </param>
/// <param name="endpoint"/>
/// <exception cref="System.IO.IOException"/>
internal static void Connect(SocketChannel channel, EndPoint endpoint, int timeout
)
{
bool blockingOn = channel.IsBlocking();
if (blockingOn)
{
channel.ConfigureBlocking(false);
}
try
{
if (channel.Connect(endpoint))
{
return;
}
long timeoutLeft = timeout;
long endTime = (timeout > 0) ? (Time.Now() + timeout) : 0;
while (true)
{
// we might have to call finishConnect() more than once
// for some channels (with user level protocols)
int ret = selector.Select((SelectableChannel)channel, SelectionKey.OpConnect, timeoutLeft
);
if (ret > 0 && channel.FinishConnect())
{
return;
}
if (ret == 0 || (timeout > 0 && (timeoutLeft = (endTime - Time.Now())) <= 0))
{
throw new SocketTimeoutException(TimeoutExceptionString(channel, timeout, SelectionKey
.OpConnect));
}
}
}
catch (IOException e)
{
// javadoc for SocketChannel.connect() says channel should be closed.
try
{
channel.Close();
}
catch (IOException)
{
}
throw;
}
finally
{
if (blockingOn && channel.IsOpen())
{
channel.ConfigureBlocking(true);
}
}
}
private void InitializeConnection(Java.Lang.String ipAndPort, InetAddress destinationAddress, int destinationPort,
Packet currentPacket, TCPHeader tcpHeader, ByteBuffer responseBuffer)
{
currentPacket.SwapSourceAndDestination();
if (tcpHeader.isSYN())
{
SocketChannel outputChannel = SocketChannel.Open();
outputChannel.ConfigureBlocking(false);
vpnService.Protect(outputChannel.Socket());
TCB tcb = new TCB(ipAndPort, random.NextInt(Short.MaxValue + 1), tcpHeader.sequenceNumber, tcpHeader.sequenceNumber + 1,
tcpHeader.acknowledgementNumber, outputChannel, currentPacket);
TCB.PutTCB(ipAndPort, tcb);
try
{
outputChannel.Connect(new InetSocketAddress(destinationAddress, destinationPort));
if (outputChannel.FinishConnect())
{
tcb.status = TCB.TCBStatus.SYN_RECEIVED;
// TODO: Set MSS for receiving larger packets from the device
currentPacket.updateTCPBuffer(responseBuffer, (byte)(TCPHeader.SYN | TCPHeader.ACK),
tcb.mySequenceNum, tcb.myAcknowledgementNum, 0);
tcb.mySequenceNum++; // SYN counts as a byte
}
else
{
tcb.status = TCB.TCBStatus.SYN_SENT;
selector.Wakeup();
tcb.selectionKey = outputChannel.Register(selector, SelectionKey.OpConnect, tcb);
return;
}
}
catch (IOException e)
{
Log.Error(TAG, "Connection error: " + ipAndPort, e);
currentPacket.updateTCPBuffer(responseBuffer, (byte)TCPHeader.RST, 0, tcb.myAcknowledgementNum, 0);
TCB.CloseTCB(tcb);
}
}
else
{
currentPacket.updateTCPBuffer(responseBuffer, (byte)TCPHeader.RST,
0, tcpHeader.sequenceNumber + 1, 0);
}
outputQueue.Offer(responseBuffer);
}
public void onConnectable()
{
try
{
if (mInnerChannel.FinishConnect())
{
onConnected();
Debug.WriteLine($"Connected to {mServerEP}");
}
else
{
Debug.Fail($"Connect to {mServerEP} failed.");
Dispose();
}
}
catch (Exception ex)
{
Debug.Fail($"Connect to {mServerEP.ToString()} failed: {ex}");
Dispose();
}
}
