public static async void WsTelnet(HttpListenerContext ctx)
{
Session.SessionEntry?session = Session.GetSessionEntry(ctx.Request.Cookies["sessionid"]?.Value);
string performer = Session.GetUsername(ctx.Request.Cookies["sessionid"]?.Value);
WebSocketContext wsc;
WebSocket ws;
try {
wsc = await ctx.AcceptWebSocketAsync(null);
ws = wsc.WebSocket;
} catch (WebSocketException ex) {
ctx.Response.Close();
Logging.Err(ex);
return;
}
string sessionId = ctx.Request.Cookies["sessionid"]?.Value ?? null;
if (sessionId is null)
{
ctx.Response.Close();
return;
}
Thread wsToServer = null;
try {
byte[] targetBuff = new byte[1024];
WebSocketReceiveResult targetResult = await ws.ReceiveAsync(new ArraySegment <byte>(targetBuff), CancellationToken.None);
string target = Encoding.Default.GetString(targetBuff, 0, targetResult.Count);
string[] split = target.Split(':');
string host = split[0];
int port = 23;
if (split.Length > 1)
{
int.TryParse(split[1], out port);
}
TcpClient telnet;
try {
telnet = new TcpClient(host, port);
} catch (Exception ex) {
WsWriteText(ws, ex.Message);
await ws.CloseAsync(WebSocketCloseStatus.NormalClosure, "", CancellationToken.None);
return;
}
Logging.Action(performer, $"Establish telnet connection to {host}:{port}");
//WsWriteText(ws, $"connected to {host}:{port}\n\r");
NetworkStream stream = telnet.GetStream();
wsToServer = new Thread(async() => {
Thread.Sleep(500);
while (ws.State == WebSocketState.Open) //ws to server loop
{
byte[] buff = new byte[2048];
WebSocketReceiveResult receiveResult = null;
try {
receiveResult = await ws.ReceiveAsync(new ArraySegment <byte>(buff), CancellationToken.None);
if (receiveResult.MessageType == WebSocketMessageType.Close)
{
await ws.CloseAsync(WebSocketCloseStatus.NormalClosure, "", CancellationToken.None);
telnet.Close();
break;
}
} catch { }
if (!Session.CheckAccess(sessionId)) //check session
{
ctx.Response.Close();
telnet.Close();
return;
}
try {
for (int i = 0; i < receiveResult?.Count; i++)
{
stream.Write(buff, i, 1);
}
stream.Write(new byte[] { 13 }, 0, 1); //return
} catch { }
}
});
wsToServer.Start();
while (ws.State == WebSocketState.Open) //server to ws loop
{
byte[] data = new byte[2048];
int bytes = stream.Read(data, 0, data.Length);
string responseData = Encoding.ASCII.GetString(data, 0, bytes);
if (!Session.CheckAccess(sessionId)) //check session
{
ctx.Response.Close();
telnet.Close();
return;
}
try {
WsWriteText(ws, responseData);
} catch { }
}
} catch (Exception ex) {
Logging.Err(ex);
} finally {
try {
await ws?.CloseAsync(WebSocketCloseStatus.NormalClosure, "", CancellationToken.None);
} catch { }
try {
wsToServer?.Abort();
} catch { }
}
}
