private void AuthMethodRecvCallback()
{
{
// Parse client methods
ClientFromBuffer.RequireRead(ClientFromBuffer.Size, out ArraySegment <byte> _buffer);
var buffer = (IList <byte>)_buffer;
if (buffer[0] != 0x5)
{
ConnectionReject(true);
return;
}
int nMethods = buffer[1];
var authMethodLen = nMethods + 2;
if (authMethodLen < buffer.Count)
{
ReadAtLeast(authMethodLen, AuthMethodRecvCallback);
return;
}
var hasNoAuthRequired = false;
var j = 0;
for (var i = 2; j < nMethods; i++, j++)
{
if (buffer[i] == 0x0)
{
hasNoAuthRequired = true;
break;
}
}
ClientFromBuffer.ConfirmRead(authMethodLen);
if (!hasNoAuthRequired)
{
ConnectionReject(false);
return;
}
}
{
// Select method
ClientToBuffer.Clear();
ClientToBuffer.RequireWrite(2, true, false, out ArraySegment <byte> _buffer);
var buffer = (IList <byte>)_buffer;
buffer[0] = 0x5;
buffer[1] = 0x0;
ClientToBuffer.ConfirmWrite(2);
Send(ClientToBuffer.Size, AuthMethodSendCallback);
}
}
private void OnRequestFullyReadCallback()
{
ClientFromBuffer.RequireRead(ClientFromBuffer.Size, out ArraySegment <byte> _buffer);
var buffer = (IList <byte>)_buffer;
int cmd = buffer[1];
int atyp = buffer[3];
string dstAddr;
int dstPort;
int headerLen;
switch (atyp)
{
case 1: // IPv4 address, 4 bytes
dstAddr = new IPAddress(buffer.Skip(4).Take(4).ToArray()).ToString();
dstPort = (buffer[4 + 4] << 8) + buffer[4 + 4 + 1];
headerLen = 4 + 4 + 2;
break;
case 3: // domain name, length + str
int len = buffer[4];
dstAddr = Encoding.UTF8.GetString(_buffer.Array, _buffer.Offset + 4 + 1, len);
dstPort = (buffer[4 + 1 + len] << 8) + buffer[4 + 1 + len + 1];
headerLen = 4 + 1 + len + 2;
break;
case 4: // IPv6 address, 16 bytes
dstAddr = $"[{new IPAddress(buffer.Skip(4).Take(16).ToArray())}]";
dstPort = (buffer[4 + 16] << 8) + buffer[4 + 16 + 1];
headerLen = 4 + 16 + 2;
break;
default:
Debug.WriteLine("Unsupported ATYP=" + atyp);
Stop();
return;
}
ClientFromBuffer.ConfirmRead(headerLen);
Debug.WriteLine($"connect to {dstAddr}:{dstPort}");
// Handle cmd
switch (cmd)
{
case 1:
Debug.WriteLine("CMD=" + cmd);
_server.OnClientRequestConnect(dstAddr, dstPort);
break;
case 3:
Debug.WriteLine("Unsupported CMD=" + cmd);
Reply(ServerReply.CommandNotSupported, Stop);
break;
default:
Debug.WriteLine("Unsupported CMD=" + cmd);
Reply(ServerReply.CommandNotSupported, Stop);
break;
}
}