Sokrutu Sokrutu - 6 months ago 30
Vb.net Question

RCON Client for CS Global Offensive


Hello everybody,


I'm trying to write my own little RCON-Tool in Basic using VisualStudio.NET.
The program sends the data correctly so I assume the "send"- and "connect"-part work properly. The gameserver performs the commands correctly, but i don't receive any message back.

My function

buildTcpPacket
just builds a byte-array according to the source-rcon-protocol.

The parameters are the actual command (or password when conencting the first time), the type of request (2 for commands, 3 for authentification) and the ID of the packet, which, according to my research, is not important unless multiple connections are open.

Up until now, i have tried two very similar methods:


Method 1:


Public Function connect() As String
Try
' First, build the authentictation request.
Dim authPacket As Byte() = buildTcpPacket(rcon_password, 3, 1)
' Create a TCP-client.*
client = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
' Connect the client to the server.
client.Connect(ip, rcon_port)
' Try to autheticate.
client.Send(authPacket)
' Create the buffer to read to. Max. package size is 4096 byte.
Dim buffer(4095) As Byte
' Listen for the answer.
client.Receive(buffer)
Return System.Text.ASCII.Encoding.getString(buffer)
Catch ex As Exception
MessageBox.Show(ex.Message)
Return "-1"
End Try
End Function

Public Function sendCommand(ByVal rconCommand As String) As String
Try
' Build the package with Type = 2 (= Input to server).
Dim cmdPacket As Byte() = buildTcpPacket(rconCommand, 2, 1)
' Send the command.
client.Send(cmdPacket, SocketFlags.None)
' Create the buffer to read to. Max. package size is 4096 byte.
Dim buffer(4095) As Byte
' Listen for the answer.
client.Receive(buffer)
Return Encoding.ASCII.GetString(buffer)
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Function



And Method 2:


Private Sub connect()
Try
Dim client As New TcpClient(server, port)
Dim data As Byte() = buildTcpPacket(rcon_password, 3, id)
Dim stream As NetworkStream = client.GetStream()
stream.Write(data, 0, data.Length)

data = New Byte(4095) {}
Dim bytes As Int32 = stream.Read(data, 0, data.Length)
Dim response As String = Encoding.ASCII.GetString(data, 0, bytes)
MsgBox("received: " & response)

data = buildTcpPacket(rcon_command, 2, id)
stream.Write(data, 0, data.Length)

data = New Byte(4095) {}
bytes = stream.Read(data, 0, data.Length
response = Encoding.ASCII.GetString(data, 0, bytes)
MsgBox("received: " & response)

stream.Close()
client.Close()
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub


I only created method 2 to make sure that method 1 has no other problem than the RCON-part, since it is embedded in a larger, more complicated program.

I'm sorry if my English is terrible, all help appreciated.

Answer

Found the solution: Encoding.ASCII.GetString() ends encoding the stream/array once it found a terminator symbol. For some strange reason the RCON server seems to send gibberish data before actually answering.

Sorry I can't provide any code, lost my project while migrating to a new machine. Still wanted to provide an answer though, if anyone ever runs into the same problem.

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