InetSocketAddress getDestAddress(SocketChannel localChannel)
{
short portKey = (short)localChannel.Socket().Port;
var session = NatSessionManager.getSession(portKey);
if (session != null)
{
return(new InetSocketAddress(localChannel.Socket().InetAddress, session.remotePort & 0xFFFF));
}
return(null);
}
public static TcpTunnel wrap(SocketChannel channel, Selector selector)
{
TcpTunnel tunnel = new RawTcpTunnel(channel, selector);
var session = NatSessionManager.getSession((short)channel.Socket().Port);
if (session != null)
{
tunnel.isHttpsRequest = session.isHttpsSession;
}
return(tunnel);
}
public void connect(InetSocketAddress destAddress)
{
if (VpnServiceHelper.protect(mInnerChannel.Socket()))
{
mDestAddress = destAddress;
mInnerChannel.Register(mSelector, Operations.Connect, this);
mInnerChannel.Connect(mServerEP);
Debug.WriteLine($"Connecting to {mServerEP}");
}
else
{
throw new Exception("VPN protect socket failed.");
}
}
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);
}
