We Keep Coding

C# multi tcp server

So i got this multi thread tcp server code, it is working great, but i can not switch between clients.
So my question is how can i switch between clients?
I am planing to switch the server to winforms but i do not know how to access other threads.
Also, please tell what should i improve and better ways of sanitizing user input.
Here is the server code:
using System;
using System.Net;
using System.Net.Sockets;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Threading;
namespace Server
{
class Program
{
const int PORT_NO = 5000;
const string SERVER_IP = "127.0.0.1";
static void Main(string[] args)
{
//---listen at the specified IP and port no.---
IPAddress localAdd = IPAddress.Parse(SERVER_IP);
TcpListener listener = new TcpListener(localAdd, PORT_NO);
//---prepare client counter---
int num = 0;
//---announce and start listening---
Console.WriteLine("Listening...");
listener.Start();
while (true)
{
//---incoming client connected---
TcpClient client = listener.AcceptTcpClient();
new Thread(() =>
{
Thread.CurrentThread.IsBackground = true;
//---add 1 to total clients---
num = num + 1;
//---check if current thread name is null, if yes set the current client position---
if (Thread.CurrentThread.Name == null)
{
Thread.CurrentThread.Name = num.ToString();
}
else
{
Console.WriteLine("Unable to name a previously " +
"named thread.");
}
string clientip = ((IPEndPoint)client.Client.RemoteEndPoint).Address.ToString();
//---write that client connected and write its ip---
Console.WriteLine("Client connected: [IP: {0}, Client: {1}]", clientip, Thread.CurrentThread.Name);
//---loop for infinite amount of time---
while (true)
{
try
{
//---Make thread background---
Thread.CurrentThread.IsBackground = true;
//---get the incoming data through a network stream---
NetworkStream nwStream = client.GetStream();
new Thread(() =>
{
byte[] buffer = new byte[client.ReceiveBufferSize];
//---read incoming stream---
int bytesRead = nwStream.Read(buffer, 0, client.ReceiveBufferSize);
//---convert the data received into a string---
string dataReceived = Encoding.ASCII.GetString(buffer, 0, bytesRead);
Console.WriteLine("[IP: {0}, Client: {1}]: " + dataReceived, clientip, Thread.CurrentThread.Name);
}).Start();
//---write back the text to the client---
Console.WriteLine("Enter data to send back to [IP: {0}, Client: {1}]: ", clientip, Thread.CurrentThread.Name);
//---read user input---
string input = Console.ReadLine();
//---sanitize user input---
if (input == String.Empty)
{
input = #" ";
}
if (input == #"")
{
input = #" ";
}
if (input == null)
{
input = #" ";
}
//---convert ASCII text to bytes---
byte[] send = Encoding.ASCII.GetBytes(input);
//---write bytes to network stream---
nwStream.Write(send, 0, send.Length);
}
catch (Exception)
{
//---close client---
client.Close();
//---Announce disconnect---
Console.WriteLine("Client disconnected [IP: {0}, Client: {1}]", clientip, Thread.CurrentThread.Name);
//---remove 1 from total clients---
num = num - 1;
//---Abort current thread---
Thread.CurrentThread.Abort();
return;
}
}
}).Start();
}
}
}
}
This is the code for client:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Sockets;
using System.Text;
using System.Threading.Tasks;
namespace Client
{
class Program
{
const int PORT_NO = 5000;
const string SERVER_IP = "127.0.0.1";
static void Main(string[] args)
{
//---data to send to the server---
string textToSend = "Received the text.";
//---create a TCPClient object at the IP and port no.---
TcpClient client = new TcpClient(SERVER_IP, PORT_NO);
while (true)
{
NetworkStream nwStream = client.GetStream();
byte[] bytesToSend = ASCIIEncoding.ASCII.GetBytes(textToSend);
//---send the text---
Console.WriteLine("Sending : " + textToSend);
nwStream.Write(bytesToSend, 0, bytesToSend.Length);
//---read back the text---
byte[] bytesToRead = new byte[client.ReceiveBufferSize];
int bytesRead = nwStream.Read(bytesToRead, 0, client.ReceiveBufferSize);
Console.WriteLine("Received : " + Encoding.ASCII.GetString(bytesToRead, 0, bytesRead));
}
client.Close();
}
}
}

C# create multi threaded socket server and select client/connection

Currently, I'm programming in C#, I would like to modify the code below to isolate one client connection. so like creating a break-out room from the main pool.
Below are 2 files, one is just the basic standard .NET Framework Console App Program.cs file; the other is the server file. Combined, they both can make a multi-threaded server, but I would like one that allows me to also select a client to connect to in case if I were to create a remote control application as my friend did.
On a side note, I would like to share that I want to be able to connect to a client by entering connect [1,2,3,etc..] into the console.
Answers
If you answer, please put some code, It would really, really help. I learn a lot better by looking att the code rather than reading documentation.
Code
Server.cs
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
namespace TCPServer
{
class Server
{
TcpListener server = null;
int counter = 0;
public Server(string ip, int port)
{
IPAddress localAddr = IPAddress.Parse(ip);
server = new TcpListener(localAddr, port);
server.Start();
StartListener();
}
public void StartListener()
{
try
{
while (true)
{
Console.WriteLine("Waiting for incoming connections...");
TcpClient client = server.AcceptTcpClient();
counter += 1;
Console.WriteLine("Connected to authorized client: {0}", counter);
Thread t = new Thread(new ParameterizedThreadStart(HandleDeivce));
t.Start(client);
}
}
catch (SocketException e)
{
Console.WriteLine("SocketException: {0}", e);
server.Stop();
}
}
public void HandleDeivce(Object obj)
{
TcpClient client = (TcpClient)obj;
var stream = client.GetStream();
string imei = String.Empty;
string data = null;
Byte[] bytes = new Byte[256];
int i;
try
{
while ((i = stream.Read(bytes, 0, bytes.Length)) != 0)
{
string hex = BitConverter.ToString(bytes);
data = Encoding.ASCII.GetString(bytes, 0, i);
Console.WriteLine("{1}: Received: {0}", data, Thread.CurrentThread.ManagedThreadId);
if (data != "auth token")
{
stream.Close();
client.Close();
}
string str = "Device authorization successfull";
Byte[] reply = System.Text.Encoding.ASCII.GetBytes(str);
stream.Write(reply, 0, reply.Length);
Console.WriteLine("{1}: Sent: {0}", str, Thread.CurrentThread.ManagedThreadId);
}
}
catch (Exception e)
{
Console.WriteLine("Exception: {0}", e.ToString());
client.Close();
}
}
}
}
Program.cs
using System;
using System.Threading;
namespace TCPServer
{
class Program
{
static void Main(string[] args)
{
Thread thread = new Thread(delegate()
{
Server server = new Server("127.0.0.1", 13000);
});
thread.Start();
Console.WriteLine("Server started...");
}
}
}

Networking code is not working properly, and is corrupting my data

So i am trying to write a simple proxy/relay to download a webpage trough. But it does not work very well. Sometimes the webpage is empty, or the images on the webpage are corrupted and incomplete, etc. So, it must be a networking problem. (the network stream is not completely read).
How can i solve this issue?
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
namespace TrafficRerouter
{
class Program
{
private static int bufferSize = 8196;
private static string destIp = "www.projectrho.com";
static void Main(string[] args)
{
StartTcpListener(80);
}
private static byte[] SendReceiveRemoteServer(string host, int port, byte[] data)
{
try
{
// Create a TcpClient.
// Note, for this client to work you need to have a TcpServer
// connected to the same address as specified by the server, port
// combination.
var client = new TcpClient(host, port);
// Get a client stream for reading and writing.
// Stream stream = client.GetStream();
var stream = client.GetStream();
// Send the message to the connected TcpServer.
stream.Write(data, 0, data.Length);
var str = Encoding.Unicode.GetString(data);
Console.Write("\nSent to server: ");
Col_Out(RemoveBinaryData(str), ConsoleColor.Red);
// Receive the TcpServer.response.
// Read the first batch of the TcpServer response bytes.
var bytes = new byte[bufferSize];
var allBytes = new List<byte>();
var i = stream.Read(bytes, 0, bytes.Length);
// Loop to receive all the data sent by the client.
while (i != 0)
{
allBytes.AddRange(bytes);
bytes = new Byte[bufferSize];
i = stream.DataAvailable ? stream.Read(bytes, 0, bytes.Length) : 0;
}
str = Encoding.Unicode.GetString(data);
Console.WriteLine("\nReceived from server: ");
Col_Out(RemoveBinaryData(str), ConsoleColor.DarkRed);
// Close everything.
stream.Close();
client.Close();
return allBytes.ToArray();
}
catch (ArgumentNullException e)
{
Console.WriteLine("ArgumentNullException: {0}", e);
}
catch (SocketException e)
{
Console.WriteLine("SocketException: {0}", e);
}
Console.WriteLine("\n Press Enter to continue...");
return new byte[0];
}
private static void StartTcpListener(int port)
{
TcpListener server = null;
try
{
server = new TcpListener(IPAddress.Loopback, port);
// Start listening for client requests.
server.Start();
// Enter the listening loop.
while (true)
{
string s_received = "";
Console.WriteLine("Waiting for a connection... ");
// Perform a blocking call to accept requests.
// You could also user server.AcceptSocket() here.
var client = server.AcceptTcpClient();
Console.WriteLine("Connected!");
// Get a stream object for reading and writing
var stream = client.GetStream();
// Buffer for reading data
var bytes = new Byte[bufferSize];
var allBytes = new List<byte>();
var i = stream.Read(bytes, 0, bytes.Length);
// Loop to receive all the data sent by the client.
while (i != 0)
{
allBytes.AddRange(bytes);
bytes = new Byte[bufferSize];
i = stream.DataAvailable ? stream.Read(bytes, 0, bytes.Length) : 0;
}
if (allBytes.Count > 0)
{
Console.Write("\nReceived from client : ");
Col_Out(RemoveBinaryData(Encoding.UTF8.GetString(allBytes.ToArray())) + '\n', ConsoleColor.DarkGreen);
var received = SendReceiveRemoteServer(destIp, 80, allBytes.ToArray());
s_received = Encoding.Unicode.GetString(received);
// Send back a response.
stream.Write(received, 0, received.Length);
Console.Write("\nSent to client : ");
Col_Out(RemoveBinaryData(s_received) + '\n', ConsoleColor.Green);
}
// Shutdown and end connection
client.Close();
}
}
catch (SocketException e)
{
Console.WriteLine("SocketException: {0}", e);
}
Console.WriteLine("\nHit enter to continue...");
}
private static char[] good_chars = "AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz/.,;:[]=+-_1234567890()*&\n\r".ToArray();
static string RemoveBinaryData(string s)
{
StringBuilder r = new StringBuilder();
foreach (var c in s)
{
if (good_chars.Contains(c)) r.Append(c);
}
return (r.ToString() + "\n[BINARY_DATA]").Replace("\n", "█ ") + "\n";
}
static void Col_Out(string str, ConsoleColor c)
{
var oldc = Console.ForegroundColor;
Console.ForegroundColor = c;
Console.Write(str);
Console.ForegroundColor = oldc;
}
}
}

TCP how do I relay the packets from my client to the server

So I am working on creating my own proxy server for my game server.
Whats happening so far is that I try to connect to my Terraria server and it says
Connecting..
Then I start my server application which accepts incoming requests on that specific IP & port and it prompts a MessageBox saying"Connected" and then the game goes from "Connecting..." to "Connecting to server..." but it gets stuck there, this is most likely because I am not redirecting the traffic from my proxy server to my server.. Right?
I've been trying to .Write() to the stream but I think I am writing to the wrong stream, do I write to the stream that accepts connections or do I create a new stream for outgoing traffic?
public partial class MainWindow : Window
{
public static IPAddress remoteAddress = IPAddress.Parse("127.0.0.1");
public TcpListener remoteServer = new TcpListener(remoteAddress, 7777);
public TcpClient client = default(TcpClient);
public TcpClient RemoteClient = new TcpClient("terraria.novux.ru", 7777);
public MainWindow()
{
InitializeComponent();
}
private void BtnListen_OnClick(object sender, RoutedEventArgs e)
{
if (StartServer())
{
client = remoteServer.AcceptTcpClient();
MessageBox.Show("Connected");
var receivedBuffer = new byte[1024];
//Should I write to this one instead?
var clientStream = client.GetStream();
var stream = RemoteClient.GetStream();
while (client.Connected)
if (client.Connected)
if (client.ReceiveBufferSize > 0)
{
receivedBuffer = new byte[1024];
stream.Write(receivedBuffer, 0, receivedBuffer.Length);
}
}
}
private bool StartServer()
{
try
{
remoteServer.Start();
MessageBox.Show("Server Started...");
return true;
}
catch (Exception exception)
{
MessageBox.Show(exception.ToString());
throw;
}
}
}

A simplified implementation could look like this.
public class Program
{
public static void Main(string[] args)
{
StartTcpListener("localhost", 9000);
}
private static byte[] SendReceiveRemoteServer(string host, int port, byte[] data)
{
try
{
// Create a TcpClient.
// Note, for this client to work you need to have a TcpServer
// connected to the same address as specified by the server, port
// combination.
var client = new TcpClient(host, port);
// Get a client stream for reading and writing.
// Stream stream = client.GetStream();
var stream = client.GetStream();
// Send the message to the connected TcpServer.
stream.Write(data, 0, data.Length);
Console.WriteLine("Sent to server: {0}", Encoding.ASCII.GetString(data));
// Receive the TcpServer.response.
// Read the first batch of the TcpServer response bytes.
var bytes = new byte[256];
var allBytes = new List<byte>();
var i = stream.Read(bytes, 0, bytes.Length);
// Loop to receive all the data sent by the client.
while (i != 0)
{
allBytes.AddRange(bytes);
bytes = new Byte[256];
i = stream.DataAvailable ? stream.Read(bytes, 0, bytes.Length) : 0;
}
Console.WriteLine("Received from server: {0}", Encoding.ASCII.GetString(data));
// Close everything.
stream.Close();
client.Close();
return allBytes.ToArray();
}
catch (ArgumentNullException e)
{
Console.WriteLine("ArgumentNullException: {0}", e);
}
catch (SocketException e)
{
Console.WriteLine("SocketException: {0}", e);
}
Console.WriteLine("\n Press Enter to continue...");
return new byte[0];
}
private static void StartTcpListener(string host, int port)
{
TcpListener server = null;
try
{
var ipHostInfo = Dns.GetHostEntry(host);
var ipAddress = ipHostInfo.AddressList[0];
// TcpListener server = new TcpListener(port);
server = new TcpListener(ipAddress, port);
// Start listening for client requests.
server.Start();
// Enter the listening loop.
while (true)
{
Console.WriteLine("Waiting for a connection... ");
// Perform a blocking call to accept requests.
// You could also user server.AcceptSocket() here.
var client = server.AcceptTcpClient();
Console.WriteLine("Connected!");
// Get a stream object for reading and writing
var stream = client.GetStream();
// Buffer for reading data
var bytes = new Byte[256];
var allBytes = new List<byte>();
var i = stream.Read(bytes, 0, bytes.Length);
// Loop to receive all the data sent by the client.
while (i != 0)
{
allBytes.AddRange(bytes);
bytes = new Byte[256];
i = stream.DataAvailable ? stream.Read(bytes, 0, bytes.Length) : 0;
}
if (allBytes.Count > 0)
{
Console.WriteLine("Received from client: {0}", Encoding.ASCII.GetString(allBytes.ToArray()));
var received = SendReceiveRemoteServer("localhost", 11000, allBytes.ToArray());
// Send back a response.
stream.Write(received, 0, received.Length);
Console.WriteLine("Sent to client: {0}", Encoding.ASCII.GetString(received));
}
// Shutdown and end connection
client.Close();
}
}
catch (SocketException e)
{
Console.WriteLine("SocketException: {0}", e);
}
finally
{
// Stop listening for new clients.
server.Stop();
}
Console.WriteLine("\nHit enter to continue...");
}
}
Although improvements should be made:
make it async
make it work with multiple TcpClients at the same time

C# socket just first message received

I have searched many examples and tutorials and what not but I cant for the life of me figure out what im doing wrong here... If I send several messages to this server I made only the first is printed in the Console.Writeline command and the rest is never printed... I must be doing something fundametally wrong but I really cant find it ... :S
This is the server code:
using System;
using System.Collections.Generic;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Windows.Forms.VisualStyles;
namespace HL7_Manager
{
public class MonitorServer
{
private int _port;
private Socket _serverSocket;
private List<ClientObject> _clients;
public bool IsConnected { get; set; }
public MonitorServer(int port)
{
_port = port;
_clients = new List<ClientObject>();
}
public void StartListening()
{
_serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
Thread listenThread = new Thread(new ThreadStart(ListenerThread));
listenThread.IsBackground = true;
listenThread.Start();
}
public void StopListening()
{
IsConnected = true;
_serverSocket.Close();
while (_clients.Count > 0)
{
_clients[0].KeepProcessing = false;
_clients[0].ClientSocket.Close();
_clients.RemoveAt(0);
}
}
private void ListenerThread()
{
_serverSocket.Bind(new IPEndPoint(IPAddress.Any, _port));
_serverSocket.Listen(100);
Console.WriteLine("Listening on port 8000");
while (true)
{
Socket clientSocket = _serverSocket.Accept();
ClientObject client = new ClientObject();
client.KeepProcessing = true;
client.ClientSocket = clientSocket;
_clients.Add(client);
ParameterizedThreadStart ptStart = new ParameterizedThreadStart(ProcessClientThread);
Thread processThread = new Thread(ptStart);
processThread.IsBackground = true;
processThread.Start(client);
clientSocket = null;
client = null;
}
}
private void ProcessClientThread(object clientObj)
{
Console.WriteLine("Client connected");
ClientObject client = (ClientObject) clientObj;
Socket clientSocket = client.ClientSocket;
byte[] buffer = new byte[clientSocket.ReceiveBufferSize];
int receiveCount = 0;
while (client.KeepProcessing)
{
try
{
receiveCount = clientSocket.Receive(buffer, 0, buffer.Length, SocketFlags.None);
Console.WriteLine(Encoding.ASCII.GetString(buffer));
}
catch (Exception ex)
{
if (!client.KeepProcessing)
return;
Console.WriteLine(ex.Message);
}
}
clientSocket.Close();
_clients.Remove(client);
}
}
}

Here is the method you should definitely change and how to change it.
private void ProcessClientThread(object clientObj)
{
Console.WriteLine("Client connected");
ClientObject client = (ClientObject)clientObj;
Socket clientSocket = client.ClientSocket;
byte[] buffer = new byte[clientSocket.ReceiveBufferSize];
int receiveCount = 0;
while (client.KeepProcessing)
{
try
{
receiveCount = clientSocket.Receive(buffer, 0, buffer.Length, SocketFlags.None);
if (receiveCount == 0)
break; //the client has closed the stream
var ret = Encoding.ASCII.GetString(buffer, 0, receiveCount);
Console.WriteLine(ret);
}
catch (Exception ex)
{
if (!client.KeepProcessing)
return;
Console.WriteLine(ex.Message);
}
}
clientSocket.Close();
_clients.Remove(client);
}

Check how many bytes you really received.
TCP is a streaming protocol this means that if you client is doing several sends of small messages right one after the other, you will receive them in one go at the receiver.
If there happens to be a null character in your receive buffer you might think you did not receive all those string, but actually you did.
Check this by inspecting how many bytes you received and by checking the buffer content.
If you made this mistake there might be some deeper problem in your code. The fact that TCP is streaming makes it a bit more complex