private void OnReceive(byte[] buffer, int size, IPEndPoint remoteEP)
{
uint senderId = BitConverter.ToUInt32(buffer, 0);
uint receiverId = BitConverter.ToUInt32(buffer, 4);
if (senderId == 0)
{
if (receiverId == uint.MaxValue && size >= 8 + 1 + 20) // 8=receiver+sender ids, 1=command, 20=sha1 pass
{
ExecuteCommand((TunnelCommand)buffer[8], buffer, size);
}
if (receiverId != 0)
{
return;
}
}
if ((senderId == receiverId && senderId != 0) ||
remoteEP.Address.Equals(IPAddress.Loopback) ||
remoteEP.Address.Equals(IPAddress.Any) ||
remoteEP.Address.Equals(IPAddress.Broadcast) ||
remoteEP.Port == 0)
{
return;
}
lock (_lock)
{
if (senderId == 0 && receiverId == 0)
{
if (size == 50 && !PingLimitReached(remoteEP.Address))
{
Client.Client.SendTo(buffer, 0, 12, SocketFlags.None, remoteEP);
}
return;
}
TunnelClient sender;
if (Mappings.TryGetValue(senderId, out sender))
{
if (!remoteEP.Equals(sender.RemoteEP))
{
if (sender.TimedOut && !MaintenanceModeEnabled &&
NewConnectionAllowed(remoteEP.Address, sender.RemoteEP.Address))
{
sender.RemoteEP = new IPEndPoint(remoteEP.Address, remoteEP.Port);
}
else
{
return;
}
}
sender.SetLastReceiveTick();
}
else
{
if (Mappings.Count >= MaxClients || MaintenanceModeEnabled || !NewConnectionAllowed(remoteEP.Address))
{
return;
}
sender = new TunnelClient();
sender.RemoteEP = new IPEndPoint(remoteEP.Address, remoteEP.Port);
sender.SetLastReceiveTick();
Mappings.Add(senderId, sender);
}
TunnelClient receiver;
if (Mappings.TryGetValue(receiverId, out receiver) && !receiver.RemoteEP.Equals(sender.RemoteEP))
{
Client.Client.SendTo(buffer, 0, size, SocketFlags.None, receiver.RemoteEP);
}
}
}
private void ListenerReceive(IAsyncResult result)
{
HttpListener listener = (HttpListener)result.AsyncState;
HttpListenerContext context = null;
try
{
context = listener.EndGetContext(result);
}
finally
{
listener.BeginGetContext(new AsyncCallback(ListenerReceive), listener);
}
if (context == null)
{
return;
}
var response = context.Response;
var request = context.Request;
response.KeepAlive = false;
if (!NewConnectionAllowed(request.RemoteEndPoint.Address))
{
response.StatusCode = 429; // TooManyRequests
response.Close();
return;
}
if (request.Url.AbsolutePath.StartsWith("/maintenance/"))
{
if (MaintenancePassword.Length > 0 && request.Url.AbsolutePath.Split('/')[2] == MaintenancePassword)
{
MaintenanceModeEnabled = true;
response.Close();
return;
}
response.StatusCode = (int)HttpStatusCode.Unauthorized;
response.Close();
}
else if (request.Url.AbsolutePath.Equals("/status"))
{
string status = "";
lock (_lock)
{
status =
string.Format(
"{0} slots free.\n{1} slots in use.\n", MaxClients - Mappings.Count, Mappings.Count);
}
byte[] buf = Encoding.UTF8.GetBytes(status);
response.ContentLength64 = buf.Length;
response.OutputStream.Write(buf, 0, buf.Length);
response.Close();
}
else if (request.Url.AbsolutePath.Equals("/request"))
{
if (MaintenanceModeEnabled)
{
response.StatusCode = (int)HttpStatusCode.ServiceUnavailable;
response.Close();
return;
}
int clients = 0;
if (!int.TryParse(request.QueryString["clients"], out clients) || clients < 2 || clients > 8)
{
response.StatusCode = (int)HttpStatusCode.BadRequest;
response.Close();
return;
}
var clientIds = new List <string>(clients);
lock (_lock)
{
if (Mappings.Count + clients <= MaxClients)
{
var rand = new Random();
while (clients > 0)
{
short clientId = (short)rand.Next(short.MinValue, short.MaxValue);
if (!Mappings.ContainsKey(clientId))
{
clients--;
var client = new TunnelClient();
client.SetLastReceiveTick();
Mappings.Add(clientId, client);
clientIds.Add(clientId.ToString());
}
}
}
}
if (clientIds.Count < 2)
{
response.StatusCode = (int)HttpStatusCode.ServiceUnavailable;
response.Close();
return;
}
string msg = string.Format("[{0}]", string.Join(",", clientIds));
byte[] buffer = Encoding.UTF8.GetBytes(msg);
response.ContentLength64 = buffer.Length;
response.OutputStream.Write(buffer, 0, buffer.Length);
response.Close();
}
else
{
response.StatusCode = (int)HttpStatusCode.BadRequest;
response.Close();
}
}