Socket.Receive() stop receiving and window size decrease to zero - c#

I have a tcp connection and two threads to handle sending and receiving respectively. Sometimes the receiving thread can not receive any data after a few minutes the program started,then get a Timeout error from the Receive() method. But Wireshark shows me there is data on the wire and because the program stop receiving, the receiving window size decrease to zero.
Seems like this happens more frequently on my laptop which is a windows 7 running by Parallels on Mac OS X.
class Test
{
public static string Host { get; set; }
public static int Port { get; set; }
public static Action<Exception> ErrorHandler { get; set; }
private Socket socket;
private object sendSync;
private Thread recvThread;
private Thread sendThread;
private Thread connectThread;
private readonly int RECEIVETIMOUT = 20 * 1000;
private readonly int MAXCONNECTATTEMPTINTERVAL = 27;
private int connectingAttempt = 0;
private ManualResetEvent sendReadyEvent;
private ManualResetEvent receiveReadyEvent;
private ManualResetEvent sendStoppedEvent;
private ManualResetEvent receiveStoppedEvent;
private Queue<byte[]> waitingRequests;
private Test()
{
sendSync = new object();
waitingRequests = new Queue<byte[]>();
sendReadyEvent = new ManualResetEvent(false);
receiveReadyEvent = new ManualResetEvent(false);
sendStoppedEvent = new ManualResetEvent(true);
receiveStoppedEvent = new ManualResetEvent(true);
sendThread = new Thread(this.Send);
sendThread.IsBackground = true;
sendThread.Start();
recvThread = new Thread(this.Receive);
recvThread.IsBackground = true;
recvThread.Start();
connectThread = new Thread(this.Connect);
connectThread.IsBackground = true;
connectThread.Start();
callbackThread = new Thread(this.callback);
callbackThread.IsBackground = true;
callbackThread.Start();
}
private static Test instance = null;
public static Test GetInstance()
{
if(instance == null)
instance = new Test();
return instance;
}
private void Connect()
{
while (true)
{
try
{
sendStoppedEvent.WaitOne();
receiveStoppedEvent.WaitOne();
socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
socket.ReceiveTimeout = RECEIVETIMOUT;
var ip = Dns.GetHostAddresses(Host)[0];
var endPoint = new IPEndPoint(ip, Port);
socket.Connect(endPoint);
sendStoppedEvent.Reset();
receiveStoppedEvent.Reset();
startSend();
startReceive();
}
catch (SocketException e)
{
var waitSecond = (int)Math.Pow(3, connectingAttempt);
if (waitSecond >= MAXCONNECTATTEMPTINTERVAL)
{
waitSecond = MAXCONNECTATTEMPTINTERVAL;
if(ErrorHandler !=null)
ErrorHandler(e);
}
Thread.Sleep(waitSecond * 1000);
connectingAttempt++;
}
}
}
public void Send(byte[] request)
{
lock (sendSync)
{
waitingRequests.Enqueue(request);
Monitor.Pulse(sendSync);
}
}
private void Send()
{
while (true)
{
sendReadyEvent.WaitOne();
byte[] bytes;
lock (sendSync)
{
if (waitingRequests.Count == 0)
Monitor.Wait(sendSync)
bytes = waitingRequests.Dequeue();
}
int i = 0;
while (i < bytes.Length)
{
try
{
i += socket.Send(bytes, i, bytes.Length - i, SocketFlags.None);
}
catch (SocketException e)
{
stopSend();
break;
}
catch (ObjectDisposedException e)
{
stopSend();
break;
}
}
}
}
private void stopSend()
{
socket.Close();
sendReadyEvent.Reset();
sendStoppedEvent.Set();
}
private void startSend()
{
sendReadyEvent.Set();
}
private int totalReceived = 0;
private int recevied = 0;
private void Receive()
{
int RECVBUFFERSIZE = 1024 * 1024 * 2;
byte[] recvBuffer = new byte[RECVBUFFERSIZE];
while (true)
{
receiveReadyEvent.WaitOne();
try
{
recevied = socket.Receive(recvBuffer, totalReceived, 1024, SocketFlags.None);
if (recevied == 0)
stopReceive();
totalReceived += recevied;
//parse data
......
}
catch (SocketException e)
{
stopReceive();
}
catch (ObjectDisposedException e)
{
stopReceive();
}
}
}
private void stopReceive()
{
totalReceived = 0;
recevied = 0;
socket.Close();
receiveReadyEvent.Reset();
receiveStoppedEvent.Set();
}
private void startReceive()
{
receiveReadyEvent.Set();
}
}
Here is the Wireshark dump
No. Time Source Destination Protocol Length Info
4850 1971.053146 client server TCP 90 netview-aix-3 > autodesk-nlm [PSH, ACK] Seq=7969 Ack=188674 Win=232 Len=36
No. Time Source Destination Protocol Length Info
4851 1971.077669 server client TCP 286 [TCP Window Full] autodesk-nlm > netview-aix-3 [PSH, ACK] Seq=188674 Ack=7969 Win=28544 Len=232
No. Time Source Destination Protocol Length Info
4852 1971.077672 server client TCP 60 autodesk-nlm > netview-aix-3 [ACK] Seq=188906 Ack=8005 Win=28544 Len=0
No. Time Source Destination Protocol Length Info
4853 1971.077766 client server TCP 189 [TCP ZeroWindow] netview-aix-3 > autodesk-nlm [PSH, ACK] Seq=8005 Ack=188906 Win=0 Len=135

Related

Connection Refused to Server when using SOCKS5 Proxy and Tor C#

I have this code that uses SOCKS5 Proxy to connect to Tor and then tries to connect the Client to the remote Server on a VPS machine that runs a C# server. The problem is I can't establish the connection.
The Server is written in C#, it listens to connections on port 1604 and it's a hidden service meaning any traffic that comes trough port 1604 will be redirected to 127.0.0.1:1604 where my server listens.
Test 1
When I connected directly to test if my client get make a HTTP request to a webserver on port 80 it works, when i use the .onion address to access the webserver it works too. When I check yougetsignal using the remote machine IP it's open as you can see
Also here is the torrc FILE config
GREAT EVERYTHING WORKS SO FAR, BUT WAIT A SECOND
Test 2
When I try to connect the client to my standalone server (not a webserver) directly it works like I expected it to do, but when i try to use the HOSTNAME generated by tor.exe (the same HOSTNAME I used in Test 1) i get Connection Refused and General SOCKS server failure.
I can't find what I'm doing wrong and why I can't reach my server, please assist me and thank you for your time.
The Code
Client
Socks Code
public class ConnectionException : ApplicationException
{
public ConnectionException(string message)
: base(message)
{
}
}
/// <summary>
/// Provides sock5 functionality to clients (Connect only).
/// </summary>
public class SocksProxy
{
private SocksProxy() { }
#region ErrorMessages
private static string[] errorMsgs = {
"Operation completed successfully.",
"General SOCKS server failure.",
"Connection not allowed by ruleset.",
"Network unreachable.",
"Host unreachable.",
"Connection refused.",
"TTL expired.",
"Command not supported.",
"Address type not supported.",
"Unknown error."
};
#endregion
public static Socket ConnectToSocks5Proxy(string proxyAdress, ushort proxyPort, string destAddress, ushort destPort,
string userName, string password)
{
IPAddress destIP = null;
IPAddress proxyIP = null;
byte[] request = new byte[257];
byte[] response = new byte[257];
ushort nIndex;
try
{
proxyIP = IPAddress.Parse(proxyAdress);
}
catch (FormatException)
{ // get the IP address
proxyIP = Dns.GetHostByAddress(proxyAdress).AddressList[0];
}
// Parse destAddress (assume it in string dotted format "212.116.65.112" )
try
{
destIP = IPAddress.Parse(destAddress);
}
catch (FormatException)
{
// wrong assumption its in domain name format "www.microsoft.com"
}
IPEndPoint proxyEndPoint = new IPEndPoint(proxyIP, proxyPort);
// open a TCP connection to SOCKS server...
Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
s.Connect(proxyEndPoint);
nIndex = 0;
request[nIndex++] = 0x05; // Version 5.
request[nIndex++] = 0x01; // 2 Authentication methods are in packet...
request[nIndex++] = 0x00; // NO AUTHENTICATION REQUIRED
//request[nIndex++] = 0x02; // USERNAME/PASSWORD
// Send the authentication negotiation request...
s.Send(request, nIndex, SocketFlags.None);
// Receive 2 byte response...
int nGot = s.Receive(response, 2, SocketFlags.None);
if (nGot != 2)
throw new ConnectionException("Bad response received from proxy server.");
if (response[1] == 0xFF)
{ // No authentication method was accepted close the socket.
s.Close();
throw new ConnectionException("None of the authentication method was accepted by proxy server.");
}
byte[] rawBytes;
if (/*response[1]==0x02*/false)
{//Username/Password Authentication protocol
nIndex = 0;
request[nIndex++] = 0x05; // Version 5.
// add user name
request[nIndex++] = (byte)userName.Length;
rawBytes = Encoding.Default.GetBytes(userName);
rawBytes.CopyTo(request, nIndex);
nIndex += (ushort)rawBytes.Length;
// add password
request[nIndex++] = (byte)password.Length;
rawBytes = Encoding.Default.GetBytes(password);
rawBytes.CopyTo(request, nIndex);
nIndex += (ushort)rawBytes.Length;
// Send the Username/Password request
s.Send(request, nIndex, SocketFlags.None);
// Receive 2 byte response...
nGot = s.Receive(response, 2, SocketFlags.None);
if (nGot != 2)
throw new ConnectionException("Bad response received from proxy server.");
if (response[1] != 0x00)
throw new ConnectionException("Bad Usernaem/Password.");
}
// This version only supports connect command.
// UDP and Bind are not supported.
// Send connect request now...
nIndex = 0;
request[nIndex++] = 0x05; // version 5.
request[nIndex++] = 0x01; // command = connect.
request[nIndex++] = 0x00; // Reserve = must be 0x00
if (destIP != null)
{// Destination adress in an IP.
switch (destIP.AddressFamily)
{
case AddressFamily.InterNetwork:
// Address is IPV4 format
request[nIndex++] = 0x01;
rawBytes = destIP.GetAddressBytes();
rawBytes.CopyTo(request, nIndex);
nIndex += (ushort)rawBytes.Length;
break;
case AddressFamily.InterNetworkV6:
// Address is IPV6 format
request[nIndex++] = 0x04;
rawBytes = destIP.GetAddressBytes();
rawBytes.CopyTo(request, nIndex);
nIndex += (ushort)rawBytes.Length;
break;
}
}
else
{// Dest. address is domain name.
request[nIndex++] = 0x03; // Address is full-qualified domain name.
request[nIndex++] = Convert.ToByte(destAddress.Length); // length of address.
rawBytes = Encoding.Default.GetBytes(destAddress);
rawBytes.CopyTo(request, nIndex);
nIndex += (ushort)rawBytes.Length;
}
// using big-edian byte order
byte[] portBytes = BitConverter.GetBytes(destPort);
for (int i = portBytes.Length - 1; i >= 0; i--)
request[nIndex++] = portBytes[i];
// send connect request.
s.Send(request, nIndex, SocketFlags.None);
// Point of breaking !!!!!!!!!!!!!!!!!!!!!!!!!!!!!
s.Receive(response); // Get variable length response...
if (response[1] != 0x00)
throw new ConnectionException(errorMsgs[response[1]]); // Crashes the Client !!!!!!!!!!!
// Success Connected...
return s;
}
}
Main Code
Socket s;
// s = SocksProxy.ConnectToSocks5Proxy("127.0.0.1", 9150, "xoembwt22tmxseask2qyuudbxoubiuafw54klkwuktvv6bxbhrdffqyd.onion", 1604, "U$er", "Pa$$word!"); //NOT WORKING
//s = SocksProxy.ConnectToSocks5Proxy("127.0.0.1", 9150, "xoembwt22tmxseask2qyuudbxoubiuafw54klkwuktvv6bxbhrdffqyd.onion", 80, "", ""); // WORKING
s = SocksProxy.ConnectToSocks5Proxy("127.0.0.1", 9150, "xoembwt22tmxseask2qyuudbxoubiuafw54klkwuktvv6bxbhrdffqyd.onion", 1604, "", ""); //NOT WORKING
// s = SocksProxy.ConnectToSocks5Proxy("127.0.0.1", 9150, "X.X.X.100", 1604, "", ""); //WORKING
//client is a TCPClient
client.Client = s;
Server
Server Class
public class Server : Common
{
private static int counter;
private readonly ConcurrentDictionary<int, ClientToken> clients = new ConcurrentDictionary<int, ClientToken>();
public TcpListener listener;
private Thread listenerThread;
public bool Active => listenerThread != null && listenerThread.IsAlive;
public static int NextConnectionId()
{
int id = Interlocked.Increment(ref counter);
if (id == int.MaxValue) throw new Exception("connection id limit reached: " + id);
return id;
}
private void Listen(int port)
{
try
{
listener = new TcpListener(new IPEndPoint(IPAddress.Any, port));
listener.Server.NoDelay = NoDelay;
listener.Server.SendTimeout = SendTimeout;
listener.Start();
Logger.Log("Server: listening port=" + port);
while (true)
{
TcpClient client = listener.AcceptTcpClient();
int connectionId = NextConnectionId();
ClientToken token = new ClientToken(client);
clients[connectionId] = token;
Thread sendThread = new Thread(() =>
{
try
{
SendLoop(connectionId, client, token.sendQueue, token.sendPending);
}
catch (ThreadAbortException) { }
catch (Exception exception)
{
Logger.LogError("Server send thread exception: " + exception);
}
});
sendThread.IsBackground = true;
sendThread.Start();
Thread receiveThread = new Thread(() =>
{
try
{
ReceiveLoop(connectionId, client, receiveQueue, MaxMessageSize);
clients.TryRemove(connectionId, out ClientToken _);
sendThread.Interrupt();
}
catch (Exception exception)
{
Logger.LogError("Server client thread exception: " + exception);
}
});
receiveThread.IsBackground = true;
receiveThread.Start();
}
}
catch (ThreadAbortException exception)
{
Logger.Log("Server thread aborted. That's okay. " + exception);
}
catch (SocketException exception)
{
Logger.Log("Server Thread stopped. That's okay. " + exception);
}
catch (Exception exception)
{
Logger.LogError("Server Exception: " + exception);
}
}
public bool Start(int port)
{
if (Active) return false;
receiveQueue = new ConcurrentQueue<Message>();
Logger.Log("Server: Start port=" + port);
listenerThread = new Thread(() => { Listen(port); });
listenerThread.IsBackground = true;
listenerThread.Priority = ThreadPriority.BelowNormal;
listenerThread.Start();
return true;
}
public void Stop()
{
if (!Active) return;
Logger.Log("Server: stopping...");
listener?.Stop();
listenerThread?.Interrupt();
listenerThread = null;
foreach (KeyValuePair<int, ClientToken> kvp in clients)
{
TcpClient client = kvp.Value.client;
try
{
client.GetStream().Close();
}
catch { }
client.Close();
}
clients.Clear();
}
public bool Send(int connectionId, byte[] data)
{
if (data.Length <= MaxMessageSize)
{
ClientToken token;
if (clients.TryGetValue(connectionId, out token))
{
token.sendQueue.Enqueue(data);
token.sendPending.Set();
return true;
}
Logger.Log("Server.Send: invalid connectionId: " + connectionId);
return false;
}
Logger.LogError("Client.Send: message too big: " + data.Length + ". Limit: " + MaxMessageSize);
return false;
}
public string GetClientAddress(int connectionId)
{
ClientToken token;
if (clients.TryGetValue(connectionId, out token))
return ((IPEndPoint) token.client.Client.RemoteEndPoint).Address.ToString();
return "";
}
public bool Disconnect(int connectionId)
{
ClientToken token;
if (clients.TryGetValue(connectionId, out token))
{
token.client.Close();
Logger.Log("Server.Disconnect connectionId:" + connectionId);
return true;
}
return false;
}
private class ClientToken
{
public readonly TcpClient client;
public readonly ManualResetEvent sendPending = new ManualResetEvent(false);
public readonly SafeQueue<byte[]> sendQueue = new SafeQueue<byte[]>();
public ClientToken(TcpClient client)
{
this.client = client;
}
}
}
Common
public abstract class Common
{
public static int messageQueueSizeWarning = 100000;
public int MaxMessageSize = 2147483647;
public bool NoDelay = true;
protected ConcurrentQueue<Message> receiveQueue = new ConcurrentQueue<Message>();
public int SendTimeout = 5000;
public int ReceiveQueueCount => receiveQueue.Count;
public bool GetNextMessage(out Message message)
{
return receiveQueue.TryDequeue(out message);
}
protected static bool SendMessagesBlocking(NetworkStream stream, byte[][] messages)
{
try
{
int packetSize = 0;
for (int i = 0; i < messages.Length; ++i)
packetSize += sizeof(int) + messages[i].Length;
byte[] payload = new byte[packetSize];
int position = 0;
for (int i = 0; i < messages.Length; ++i)
{
byte[] header = Utils.IntToBytesBigEndian(messages[i].Length);
Array.Copy(header, 0, payload, position, header.Length);
Array.Copy(messages[i], 0, payload, position + header.Length, messages[i].Length);
position += header.Length + messages[i].Length;
}
stream.Write(payload, 0, payload.Length);
return true;
}
catch (Exception exception)
{
Logger.Log("Send: stream.Write exception: " + exception);
return false;
}
}
protected static bool ReadMessageBlocking(NetworkStream stream, int MaxMessageSize, out byte[] content)
{
content = null;
byte[] header = new byte[4];
if (!stream.ReadExactly(header, 4))
return false;
int size = Utils.BytesToIntBigEndian(header);
if (size <= MaxMessageSize)
{
content = new byte[size];
return stream.ReadExactly(content, size);
}
Logger.LogWarning("ReadMessageBlocking: possible allocation attack with a header of: " + size + " bytes.");
return false;
}
protected static void ReceiveLoop(int connectionId, TcpClient client, ConcurrentQueue<Message> receiveQueue,
int MaxMessageSize)
{
NetworkStream stream = client.GetStream();
DateTime messageQueueLastWarning = DateTime.Now;
try
{
receiveQueue.Enqueue(new Message(connectionId, EventType.Connected, null));
while (true)
{
byte[] content;
if (!ReadMessageBlocking(stream, MaxMessageSize, out content))
break;
receiveQueue.Enqueue(new Message(connectionId, EventType.Data, content));
if (receiveQueue.Count > messageQueueSizeWarning)
{
TimeSpan elapsed = DateTime.Now - messageQueueLastWarning;
if (elapsed.TotalSeconds > 10)
{
Logger.LogWarning("ReceiveLoop: messageQueue is getting big(" + receiveQueue.Count +
"), try calling GetNextMessage more often. You can call it more than once per frame!");
messageQueueLastWarning = DateTime.Now;
}
}
}
}
catch (Exception exception)
{
Logger.Log("ReceiveLoop: finished receive function for connectionId=" + connectionId + " reason: " +
exception);
}
stream.Close();
client.Close();
receiveQueue.Enqueue(new Message(connectionId, EventType.Disconnected, null));
}
protected static void SendLoop(int connectionId, TcpClient client, SafeQueue<byte[]> sendQueue,
ManualResetEvent sendPending)
{
NetworkStream stream = client.GetStream();
try
{
while (client.Connected)
{
sendPending.Reset();
byte[][] messages;
if (sendQueue.TryDequeueAll(out messages))
if (!SendMessagesBlocking(stream, messages))
return;
sendPending.WaitOne();
}
}
catch (ThreadAbortException) { }
catch (ThreadInterruptedException) { }
catch (Exception exception)
{
Logger.Log("SendLoop Exception: connectionId=" + connectionId + " reason: " + exception);
}
}
}

Networkstream multiple threads and transferring data

I have a application that uses a Networkstream to communicate with a server. Reading and writing takes place on two different threads. One thread is always listening for data coming from the server and the other thread writes data to the stream to send a request. The server then processes the data and then sends back a order number, but since I am writing and reading on two threads I canĀ“t read on the thread on which I initially send the data to the sever.
My Problem is that I create a listviewitem for each request I send to the server and I somehow need to identify the listviewitem that corresponds to the received order number.
private void SendCheckoutData()
{
//Start sending data
manager.SendInt(TableId);
Thread.Sleep(80);
manager.SendInt(ClientId);
Thread.Sleep(80);
manager.SendInt(ListViewCheckoutTable.Items.Count);
Thread.Sleep(80);
manager.SendInt(GetCombinedPrice());
Thread.Sleep(80);
int NumberOfItems = 0;
for (int i = 0; i < ListViewCheckoutTable.Items.Count; i++)
{
OrderMenuItem item = (OrderMenuItem)ListViewCheckoutTable.Items.GetItemAt(i);
manager.SendInt(item.Id);
Thread.Sleep(80);
manager.SendInt(item.Quantity);
Thread.Sleep(80);
NumberOfItems += item.Quantity;
}
int OrderNumber; //The variable I somehow need to assign the value to
ListViewPendingOrders.Items.Add(new PendingOrderMenuItem { OrderNumber = OrderNumber, Quantity = NumberOfItems, TotalPrice = GetCombinedPrice() });
}
TCPManager
class TCPManager
{
private readonly string ip;
private readonly int port;
TcpClient client;
NetworkStream stream;
Task ListenerTask;
CancellationTokenSource cancelToken = new CancellationTokenSource();
public TCPManager(string ip, int port)
{
this.ip = ip;
this.port = port;
}
public void Connect()
{
client = new TcpClient(ip, port);
stream = client.GetStream();
}
public void Disconnect()
{
cancelToken.Cancel();
while (!ListenerTask.IsCompleted)
{
Thread.Sleep(10);
}
stream.Close();
client.Close();
}
public void ReadData()
{
ListenerTask = new Task(() =>
{
while (true)
{
while (!stream.DataAvailable)
{
Thread.Sleep(100);
}
Thread.Sleep(100);
StartNewTask(GetInt());
}
}, cancelToken.Token, TaskCreationOptions.LongRunning);
}
private void StartNewTask(int request)
{
switch (request)
{
case RequestIds.REQUEST_ORDERNUMBER:
break;
case RequestIds.REQUEST_ORDER_COMPLETED:
break;
}
}
public int GetInt()
{
byte[] bData = new byte[sizeof(int)];
stream.Read(bData, 0, bData.Length);
int Data = BitConverter.ToInt32(bData, 0);
return Data;
}

C# - Multithreaded TCP Server/Client

I am trying to understand the correct way of how should I make good multithreaded TCP server.
Here is what I have so far:
public class WorldServer
{
public List<ServerClient> clients = new List<ServerClient>();
public int port = 8080;
public TcpListener server;
private bool serverStarted;
private int connectionIncrementor;
private MySQLConnection mySQLConnection = new MySQLConnection();
private MySqlConnection mysqlConn = null;
static void Main(string[] args)
{
WorldServer serverInstance = new WorldServer();
Console.WriteLine("Starting World Server...");
try
{
serverInstance.mysqlConn = new MySqlConnection(serverInstance.mySQLConnection.mysqlConnectionString);
serverInstance.mysqlConn.Open();
Console.WriteLine("Connected to MySQL version: " + serverInstance.mysqlConn.ServerVersion + "\n");
}
catch (Exception e)
{
Console.WriteLine("MySQL Error: " + e.ToString());
}
finally
{
if (serverInstance.mysqlConn != null)
{
serverInstance.mysqlConn.Close();
}
}
serverInstance.clients = new List<ServerClient>();
try
{
serverInstance.server = new TcpListener(IPAddress.Any, serverInstance.port);
serverInstance.server.Start();
serverInstance.StartListening();
serverInstance.serverStarted = true;
Console.WriteLine("Server has been started on port: " + serverInstance.port);
}
catch (Exception e)
{
Console.WriteLine("Socket error: " + e.Message);
}
while (true)
{
serverInstance.Update();
}
}
private void Update()
{
//Console.WriteLine("Call");
if (!serverStarted)
{
return;
}
foreach (ServerClient c in clients.ToList())
{
//Check if TCP is not null
if (c.tcp == null)
return;
// Is the client still connected?
if (!IsConnected(c.tcp))
{
c.tcp.Close();
clients.Remove(c);
Console.WriteLine(c.connectionId + " has disconnected.");
continue;
//Console.WriteLine("Check for connection?\n");
}
else
{
// Check for message from Client.
NetworkStream s = c.tcp.GetStream();
if (s.DataAvailable)
{
string data = c.streamReader.ReadLine();
if (data != null)
{
if (ValidateJSON(data))
{
Thread incomingData = new Thread(() => OnIncomingData(c, data));
incomingData.Start();
}
}
}
//continue;
}
}
}
public bool ValidateJSON(string s)
{
try
{
JToken.Parse(s);
return true;
}
catch (JsonReaderException ex)
{
Trace.WriteLine(ex);
return false;
}
}
private void OnIncomingData(ServerClient c, string data)
{
dynamic json = JsonConvert.DeserializeObject(data);
string header = json.header;
//Console.WriteLine("HEADER ID:" + json.header);
string connId = json.connectionId;
int.TryParse(connId, out int connectionId);
int characterId = 0;
Dictionary<string, string> receivedData = new Dictionary<string, string>();
if (json.data != null)
{
receivedData = json.data.ToObject<Dictionary<string, string>>();
}
if (json.data["characterId"] != null)
{
characterId = json.data["characterId"];
}
string prefix = header.Substring(0, 2);
if (prefix != "1x")
{
Console.WriteLine("Unknown packet: " + data + "\n");
}
else
{
string HeaderPacket = header.Substring(2);
switch (HeaderPacket)
{
default:
Console.WriteLine("Unknown packet: " + data + "\n");
break;
case "004":
Console.WriteLine("Test Packet"); ;
break;
}
}
//Broadcast(null, data, clients);
//Console.WriteLine(c.clientName + " has sent the following message :" + data);
}
public bool IsConnected(TcpClient c)
{
try
{
if (c != null && c.Client != null && c.Client.Connected)
{
if (c.Client.Poll(0, SelectMode.SelectRead))
{
return !(c.Client.Receive(new byte[1], SocketFlags.Peek) == 0);
}
return true;
}
else
{
return false;
}
}
catch
{
return false;
}
}
private void StartListening()
{
server.BeginAcceptTcpClient(OnConnection, server);
}
private void OnConnection(IAsyncResult ar)
{
connectionIncrementor++;
TcpListener listener = (TcpListener)ar.AsyncState;
clients.Add(new ServerClient(listener.EndAcceptTcpClient(ar)));
clients[clients.Count - 1].connectionId = connectionIncrementor;
StartListening();
//Send a message to everyone, say someone has connected!
Dictionary<string, object> SendDataBroadcast = new Dictionary<string, object>();
SendDataBroadcast.Add("connectionId", clients[clients.Count - 1].connectionId);
Broadcast("001", SendDataBroadcast, clients[clients.Count - 1].connectionId);
Console.WriteLine(clients[clients.Count - 1].connectionId + " has connected.");
}
public void Broadcast(string header, Dictionary<string, object> data, int cnnId = 0)
{
string jsonData = JsonConvert.SerializeObject(data, Formatting.Indented);
foreach (ServerClient c in clients)
{
try
{
if (header == null)
{
header = "000";
}
JsonData SendData = new JsonData();
SendData.header = "0x" + header;
SendData.data = JObject.Parse(jsonData);
SendData.connectionId = cnnId;
string JSonData = JsonConvert.SerializeObject(SendData);
//Console.WriteLine("SENDING: " + JSonData);
c.streamWriter.WriteLine(JSonData);
c.streamWriter.Flush();
}
catch (Exception e)
{
Console.WriteLine("Write error : " + e.Message + " to client " + c.connectionId);
}
}
}
public void Send(string header, Dictionary<string, object> data, int cnnId)
{
string jsonData = JsonConvert.SerializeObject(data, Formatting.Indented);
foreach (ServerClient c in clients.ToList())
{
if (c.connectionId == cnnId)
{
try
{
//Console.WriteLine("Sending...");
if (header == null)
{
header = "000";
}
JsonData SendData = new JsonData();
SendData.header = "0x" + header;
SendData.data = JObject.Parse(jsonData);
SendData.connectionId = cnnId;
string JSonData = JsonConvert.SerializeObject(SendData);
c.streamWriter.WriteLine(JSonData);
c.streamWriter.Flush();
//Console.WriteLine("Trying to send data to connection id: " + cnnId + " data:" + sendData);
}
catch (Exception e)
{
Console.WriteLine("Write error : " + e.Message + " to client " + c.connectionId);
}
}
}
}
}
public class ServerClient
{
public TcpClient tcp;
public StreamReader streamReader;
public StreamWriter streamWriter;
public int accountId;
public int connectionId;
public ServerClient(TcpClient clientSocket)
{
tcp = clientSocket;
streamReader = new StreamReader(tcp.GetStream(), false);
streamWriter = new StreamWriter(tcp.GetStream());
clientSocket.NoDelay = true;
}
}
The TCP server works. However I am really not sure if this is the best approach I can take.
Have I made the multi-threading well ? Probably not. I would like to receive advices where i can make it better.
Do I need to create a new thread on every OnIncomingData ?
Do I need to create new thread on every Send and Broadcast ?
Very often I receive error here foreach (ServerClient c in clients.ToList()). What can be the cause of it ?
What parts of the client is good to be multithreaded also aka the listening function for incoming data or the sending functions?
All advices are most welcome!
I wrote code for an OP last year that was a TCP Server and wrote to a SQL Server. I modified that code a few minutes ago to make it more general. The changes are not tested but original code worked very well. I used Asynchronous Send and Receive. I also used a fifo to send messages from the transport layer to the application layer. See code below
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.Data;
using System.Data.SqlClient;
using System.Timers;
using System.Threading;
namespace TCP_Server
{
public class StateObject
{
public long connectionNumber = -1;
public Socket workSocket { get; set; }
public byte[] buffer { get; set; }
public int fifoCount { get; set; }
}
public enum PROCESS_STATE
{
ACCEPT,
READ,
PROCESS,
UNPACK
}
public enum UNPACK_STATUS
{
ERROR,
NOT_ENOUGH_BYTES,
BAD_CRC,
GOOD_MESSAGE,
DEFAULT
}
public enum PROTOCOL_NUMBER
{
LOGIN_MESSAGE,
NONE
}
class Program
{
const string IP = "127.0.0.1";
const int PORT = 8841;
const Boolean test = true;
static void Main(string[] args)
{
Server server = new Server(IP, PORT, test);
Console.WriteLine("Connection Ended");
}
}
public class Server
{
const int BUFFER_SIZE = 1024;
const string CONNECT_STRING = #"Data Source=.\SQLEXPRESS;Initial Catalog=MyDataTable;Integrated Security=SSPI;";
const string LOGIN_INSERT_COMMMAND_TEXT = "use MyTable INSERT INTO Login (TerminalID,Date) VALUES(#TerminalID,#Date)";
const string LOCATION_INSERT_COMMMAND_TEXT = "INSERT INTO MyTable (CurrTime, Message)" +
"VALUES (#CurrTime, #Message)";
static SqlConnection conn = null;
static SqlCommand cmdLogin = null;
static SqlCommand cmdLocation = null;
static long connectionNumber = 0;
//mapping of connection number to StateObject
static Dictionary<long, KeyValuePair<List<byte>, StateObject>> connectionDict = new Dictionary<long, KeyValuePair<List<byte>, StateObject>>();
//fifo contains list of connections number wait with receive data
public static List<long> fifo = new List<long>();
public static AutoResetEvent allDone = new AutoResetEvent(false);
public static AutoResetEvent acceptDone = new AutoResetEvent(false);
public enum DATABASE_MESSAGE_TYPE
{
LOGIN,
LOCATION
}
public class WriteDBMessage
{
public DATABASE_MESSAGE_TYPE message { get; set; }
}
public class WriteDBMessageLogin : WriteDBMessage
{
public DateTime date { get; set; }
public string message { get; set; }
}
public class WriteDBMessageLocation : WriteDBMessage
{
public DateTime currTime { get; set; }
public byte[] message { get; set; }
}
public static class WriteDBAsync
{
public enum Mode
{
READ,
WRITE
}
public static List<WriteDBMessage> fifo = new List<WriteDBMessage>();
public static System.Timers.Timer timer = null;
public static void WriteDatabase()
{
timer = new System.Timers.Timer(1000);
timer.Elapsed += Timer_Elapsed;
timer.Start();
}
public static WriteDBMessage ReadWriteFifo(Mode mode, WriteDBMessage message)
{
Object thisLock2 = new Object();
lock (thisLock2)
{
switch (mode)
{
case Mode.READ:
if (fifo.Count > 0)
{
message = fifo[0];
fifo.RemoveAt(0);
}
break;
case Mode.WRITE:
fifo.Add(message);
break;
}
}
return message;
}
static void Timer_Elapsed(object sender, ElapsedEventArgs e)
{
timer.Enabled = false;
WriteDBMessage row = null;
int rowsAdded = 0;
uint number = 0;
try
{
while ((row = ReadWriteFifo(Mode.READ, null)) != null)
{
switch (row.message)
{
case DATABASE_MESSAGE_TYPE.LOGIN:
cmdLogin.Parameters["#Date"].Value = ((WriteDBMessageLogin)row).date;
rowsAdded = cmdLogin.ExecuteNonQuery();
break;
}
}
}
catch (Exception ex)
{
//Console.WriteLine("Error : '{0}'", ex.Message);
}
timer.Enabled = true;
}
}
public Server(string IP, int port, Boolean test)
{
try
{
conn = new SqlConnection(CONNECT_STRING);
conn.Open();
cmdLogin = new SqlCommand(LOGIN_INSERT_COMMMAND_TEXT, conn);
cmdLogin.Parameters.Add("#TerminalID", SqlDbType.NVarChar, 8);
cmdLogin.Parameters.Add("#Date", SqlDbType.DateTime);
cmdLocation = new SqlCommand(LOCATION_INSERT_COMMMAND_TEXT, conn);
cmdLocation.Parameters.Add("#IMEI", SqlDbType.NVarChar, 50);
cmdLocation.Parameters.Add("#TrackTime", SqlDbType.DateTime);
cmdLocation.Parameters.Add("#currTime", SqlDbType.DateTime);
cmdLocation.Parameters.Add("#Longitude", SqlDbType.NChar, 50);
cmdLocation.Parameters.Add("#Lattitude", SqlDbType.NVarChar, 50);
cmdLocation.Parameters.Add("#speed", SqlDbType.Float);
}
catch (Exception ex)
{
Console.WriteLine("Error : '{0}'", ex.Message);
//Console.ReadLine();
return;
}
try
{
//initialize the timer for writing to database.
WriteDBAsync.WriteDatabase();
StartListening(IP, port, test);
// Open 2nd listener to simulate two devices, Only for testing
//StartListening(IP, port + 1, test);
ProcessMessages();
}
catch (Exception ex)
{
Console.WriteLine("Error : '{0}'", ex.Message);
//Console.ReadLine();
return;
}
}
public void StartListening(string IP, int port, Boolean test)
{
try
{
// Establish the local endpoint for the socket.
// The DNS name of the computer
// running the listener is "host.contoso.com".
IPHostEntry ipHostInfo = Dns.GetHostEntry(IP); //Dns.Resolve(Dns.GetHostName());
IPAddress ipAddress = ipHostInfo.AddressList[0];
//IPAddress local = IPAddress.Parse(IP);
IPEndPoint localEndPoint = null;
if (test)
{
localEndPoint = new IPEndPoint(IPAddress.Any, port);
}
else
{
localEndPoint = new IPEndPoint(ipAddress, port);
}
// Create a TCP/IP socket.
Socket listener = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp);
// Bind the socket to the local endpoint and listen for incoming connections.
allDone.Reset();
acceptDone.Reset();
listener.Bind(localEndPoint);
listener.Listen(100);
//login code, wait for 1st message
Console.WriteLine("Wait 5 seconds for login message");
listener.BeginAccept(new AsyncCallback(AcceptCallback), listener);
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
}
public void ProcessMessages()
{
UInt16 sendCRC = 0;
DateTime date;
int year = 0;
int month = 0;
int day = 0;
int hour = 0;
int minute = 0;
int second = 0;
KeyValuePair<List<byte>, StateObject> byteState;
KeyValuePair<UNPACK_STATUS, byte[]> status;
byte[] receiveMessage = null;
StateObject state = null;
byte[] serialNumber = null;
byte[] serverFlagBit = null;
byte[] stringArray = null;
string stringMessage = "";
byte lengthOfCommand = 0;
PROTOCOL_NUMBER protocolNumber = PROTOCOL_NUMBER.NONE;
try
{
Boolean firstMessage = true;
acceptDone.Set();
//loop forever
while (true)
{
allDone.WaitOne();
//read fifo until empty
while (true)
{
//read one connection until buffer doesn't contain any more packets
byteState = ReadWrite(PROCESS_STATE.PROCESS, null, null, -1);
if (byteState.Value.fifoCount == -1) break;
state = byteState.Value;
while (true)
{
status = Unpack(byteState);
if (status.Key == UNPACK_STATUS.NOT_ENOUGH_BYTES)
break;
if (status.Key == UNPACK_STATUS.ERROR)
{
Console.WriteLine("Error : Bad Receive Message, Data");
break;
}
//message is 2 start bytes + 1 byte (message length) + 1 byte message length + 2 end bytes
receiveMessage = status.Value;
int messageLength = receiveMessage[2];
Console.WriteLine("Status : '{0}', Receive Message : '{1}'", status.Key == UNPACK_STATUS.GOOD_MESSAGE ? "Good" : "Bad", BytesToString(receiveMessage.Take(messageLength + 5).ToArray()));
if (status.Key != UNPACK_STATUS.GOOD_MESSAGE)
{
break;
}
else
{
if (firstMessage)
{
if (receiveMessage[3] != 0x01)
{
Console.WriteLine("Error : Expected Login Message : '{0}'", BytesToString(receiveMessage));
break;
}
firstMessage = false;
}
//skip start bytes, message length. then go back 4 bytes (CRC and serial number)
serialNumber = receiveMessage.Skip(2 + 1 + messageLength - 4).Take(2).ToArray();
protocolNumber = (PROTOCOL_NUMBER)receiveMessage[3];
Console.WriteLine("Protocol Number : '{0}'", protocolNumber.ToString());
switch (protocolNumber)
{
case PROTOCOL_NUMBER.LOGIN_MESSAGE:
break;
} //end switch
}// End if
} //end while
}//end while fifo > 0
allDone.Reset();
}//end while true
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
}
static string BytesToString(byte[] bytes)
{
return string.Join("", bytes.Select(x => x.ToString("X2")));
}
static KeyValuePair<UNPACK_STATUS, byte[]> Unpack(KeyValuePair<List<byte>, StateObject> bitState)
{
List<byte> working_buffer = bitState.Key;
//return null indicates an error
if (working_buffer.Count() < 3) return new KeyValuePair<UNPACK_STATUS, byte[]>(UNPACK_STATUS.NOT_ENOUGH_BYTES, null);
int len = working_buffer[2];
if (working_buffer.Count < len + 5) return new KeyValuePair<UNPACK_STATUS, byte[]>(UNPACK_STATUS.NOT_ENOUGH_BYTES, null);
// check start and end bytes
// remove message fro workig buffer and dictionary
KeyValuePair<List<byte>, StateObject> byteState = ReadWrite(PROCESS_STATE.UNPACK, null, null, bitState.Value.connectionNumber);
if (byteState.Key.Count == 0) return new KeyValuePair<UNPACK_STATUS, byte[]>(UNPACK_STATUS.ERROR, null);
List<byte> packet = byteState.Key;
//crc test
byte[] crc = packet.Skip(len + 1).Take(2).ToArray();
ushort crcShort = (ushort)((crc[0] << 8) | crc[1]);
//skip start bytes, crc, and end bytes
return new KeyValuePair<UNPACK_STATUS, byte[]>(UNPACK_STATUS.GOOD_MESSAGE, packet.ToArray());
}
static KeyValuePair<List<byte>, StateObject> ReadWrite(PROCESS_STATE ps, Socket handler, IAsyncResult ar, long unpackConnectionNumber)
{
KeyValuePair<List<byte>, StateObject> byteState = new KeyValuePair<List<byte>, StateObject>(); ;
StateObject stateObject = null;
int bytesRead = -1;
int workingBufferLen = 0;
List<byte> working_buffer = null;
byte[] buffer = null;
Object thisLock1 = new Object();
lock (thisLock1)
{
switch (ps)
{
case PROCESS_STATE.ACCEPT:
acceptDone.WaitOne();
acceptDone.Reset();
stateObject = new StateObject();
stateObject.buffer = new byte[BUFFER_SIZE];
connectionDict.Add(connectionNumber, new KeyValuePair<List<byte>, StateObject>(new List<byte>(), stateObject));
stateObject.connectionNumber = connectionNumber++;
stateObject.workSocket = handler;
byteState = new KeyValuePair<List<byte>, StateObject>(null, stateObject);
acceptDone.Set();
break;
case PROCESS_STATE.READ:
//catch when client disconnects
//wait if accept is being called
//acceptDone.WaitOne();
try
{
stateObject = ar.AsyncState as StateObject;
// Read data from the client socket.
bytesRead = stateObject.workSocket.EndReceive(ar);
if (bytesRead > 0)
{
byteState = connectionDict[stateObject.connectionNumber];
buffer = new byte[bytesRead];
Array.Copy(byteState.Value.buffer, buffer, bytesRead);
byteState.Key.AddRange(buffer);
}
//only put one instance of connection number into fifo
if (!fifo.Contains(byteState.Value.connectionNumber))
{
fifo.Add(byteState.Value.connectionNumber);
}
}
catch (Exception ex)
{
//will get here if client disconnects
fifo.RemoveAll(x => x == byteState.Value.connectionNumber);
connectionDict.Remove(byteState.Value.connectionNumber);
byteState = new KeyValuePair<List<byte>, StateObject>(new List<byte>(), null);
}
break;
case PROCESS_STATE.PROCESS:
if (fifo.Count > 0)
{
//get message from working buffer
//unpack will later delete message
//remove connection number from fifo
// the list in the key in known as the working buffer
byteState = new KeyValuePair<List<byte>, StateObject>(connectionDict[fifo[0]].Key, connectionDict[fifo[0]].Value);
fifo.RemoveAt(0);
//put a valid value in fifoCount so -1 below can be detected.
byteState.Value.fifoCount = fifo.Count;
}
else
{
//getting here is normal when there is no more work to be performed
//set fifocount to zero so rest of code know fifo was empty so code waits for next receive message
byteState = new KeyValuePair<List<byte>, StateObject>(null, new StateObject() { fifoCount = -1 });
}
break;
case PROCESS_STATE.UNPACK:
try
{
working_buffer = connectionDict[unpackConnectionNumber].Key;
workingBufferLen = working_buffer[2];
if ((working_buffer[0] != 0x78) && (working_buffer[1] != 0x78) && (working_buffer[workingBufferLen + 3] != 0x0D) && (working_buffer[workingBufferLen + 4] != 0x0A))
{
working_buffer.Clear();
return new KeyValuePair<List<byte>, StateObject>(new List<byte>(), null);
}
List<byte> packet = working_buffer.GetRange(0, workingBufferLen + 5);
working_buffer.RemoveRange(0, workingBufferLen + 5);
byteState = new KeyValuePair<List<byte>, StateObject>(packet, null);
}
catch (Exception ex)
{
int testPoint = 0;
}
break;
}// end switch
}
return byteState;
}
public static void AcceptCallback(IAsyncResult ar)
{
try
{
// Get the socket that handles the client request.
// Retrieve the state object and the handler socket
// from the asynchronous state object.
Socket listener = (Socket)ar.AsyncState;
Socket handler = listener.EndAccept(ar);
// Create the state object.
StateObject state = ReadWrite(PROCESS_STATE.ACCEPT, handler, ar, -1).Value;
handler.BeginReceive(state.buffer, 0, BUFFER_SIZE, 0,
new AsyncCallback(ReadCallback), state);
}
catch (Exception ex)
{
int myerror = -1;
}
}
public static void ReadCallback(IAsyncResult ar)
{
try
{
StateObject state = ar.AsyncState as StateObject;
Socket handler = state.workSocket;
// Read data from the client socket.
KeyValuePair<List<byte>, StateObject> byteState = ReadWrite(PROCESS_STATE.READ, handler, ar, -1);
if (byteState.Value != null)
{
allDone.Set();
handler.BeginReceive(state.buffer, 0, BUFFER_SIZE, 0,
new AsyncCallback(ReadCallback), state);
}
else
{
int testPoint = 0;
}
}
catch (Exception ex)
{
int myerror = -1;
}
// Signal the main thread to continue.
allDone.Set();
}
}
}

.NET UDPClient: Error: An existing connection was forcibly closed by the remote host

I had a perfectly fine working console program that uses UdpClient.send to send messages to another program on the localhost (over port 7777). (which oddly enough is an almost identical version this C# script, but running in unity3d, and it has no trouble receiving with the same code).
Now I need to get replies from that program. I added a thread (see bottom) which listens on port 7778 for messages. But I am getting an error when starting saying that:
An existing connection was forcibly closed by the remote host
using Newtonsoft.Json;
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
namespace Blaster
{
class Blaster
{
UdpClient client;
IPEndPoint outPoint;
IPEndPoint inPoint;
public int oPort = 7777;
public int iPort = 7778;
public string hostName = "localhost";
public int stepNum = 0;
const int rate = 1000;
public System.Timers.Timer clock;
Thread listener;
static void Main(string[] args)
{
Blaster b = new Blaster();
b.run();
}
Blaster()
{
client = new UdpClient();
outPoint = new IPEndPoint(Dns.GetHostAddresses(hostName)[0], oPort);
inPoint = new IPEndPoint(Dns.GetHostAddresses(hostName)[0], iPort);
}
void run()
{
this.stepNum = 0;
listener = new Thread(new ThreadStart(translater));
listener.IsBackground = true;
listener.Start();
Console.WriteLine("Press Enter to do a send loop...\n");
Console.ReadLine();
Console.WriteLine("started at {0:HH:mm:ss.fff}", DateTime.Now);
start();
Console.WriteLine("Press Enter to stop");
Console.ReadLine();
stop();
client.Close();
}
void stop()
{
clock.Stop();
clock.Dispose();
}
void start()
{
clock = new System.Timers.Timer(rate);
clock.Elapsed += send;
clock.AutoReset = true;
clock.Enabled = true;
}
void send(Object source, System.Timers.ElapsedEventArgs e)
{
Console.WriteLine("sending: {0}", stepNum);
Byte[] sendBytes = Encoding.ASCII.GetBytes(message());
try
{
client.Send(sendBytes, sendBytes.Length, outPoint);
}
catch (Exception err)
{
Console.WriteLine(err.ToString());
}
}
string message()
{
Packet p = new Packet();
p.id = "car";
p.start = DateTime.Now;
p.x = 1.2f;
p.y = 0.4f;
p.z = 4.5f;
p.step = stepNum++;
string json = JsonConvert.SerializeObject(p);
return json;
}
void translater()
{
Byte[] data = new byte[0];
client.Client.Bind(inPoint);
while (true)
{
try
{
data = client.Receive(ref inPoint);
}
catch (Exception err)
{
Console.WriteLine("Blaster.translater: recieve data error: " + err.Message);
client.Close();
return;
}
string json = Encoding.ASCII.GetString(data);
Console.WriteLine(json);
Packet p = JsonConvert.DeserializeObject<Packet>(json);
}
}
}
}
Ok, I had seen some examples of folks using a single client object for both send and receive (as well as the same port). But then I saw a different port was needed if they were on the same host. Now I see you need a separate udpClient.
using Newtonsoft.Json;
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
namespace Blaster
{
class Blaster
{
UdpClient client;
IPEndPoint outPoint;
IPEndPoint inPoint;
public int oPort = 7777;
public int iPort = 7778;
public string hostName = "localhost";
public int stepNum = 0;
const int rate = 1000;
public System.Timers.Timer clock;
Thread listener;
static void Main(string[] args)
{
Blaster b = new Blaster();
b.run();
}
Blaster()
{
client = new UdpClient();
outPoint = new IPEndPoint(Dns.GetHostAddresses(hostName)[0], oPort);
inPoint = new IPEndPoint(Dns.GetHostAddresses(hostName)[0], iPort);
}
void run()
{
this.stepNum = 0;
listener = new Thread(new ThreadStart(translater));
listener.IsBackground = true;
listener.Start();
Console.WriteLine("Press Enter to do a send loop...\n");
Console.ReadLine();
Console.WriteLine("started at {0:HH:mm:ss.fff}", DateTime.Now);
start();
Console.WriteLine("Press Enter to stop");
Console.ReadLine();
stop();
client.Close();
}
void stop()
{
clock.Stop();
clock.Dispose();
}
void start()
{
clock = new System.Timers.Timer(rate);
clock.Elapsed += send;
clock.AutoReset = true;
clock.Enabled = true;
}
void send(Object source, System.Timers.ElapsedEventArgs e)
{
Console.WriteLine("sending: {0}", stepNum);
Byte[] sendBytes = Encoding.ASCII.GetBytes(message());
try
{
client.Send(sendBytes, sendBytes.Length, outPoint);
}
catch (Exception err)
{
Console.WriteLine(err.ToString());
}
}
string message()
{
Packet p = new Packet();
p.id = "car";
p.start = DateTime.Now;
p.x = 1.2f;
p.y = 0.4f;
p.z = 4.5f;
p.step = stepNum++;
string json = JsonConvert.SerializeObject(p);
return json;
}
void translater()
{
UdpClient server = new UdpClient();
Byte[] data = new byte[0];
server.Client.Bind(inPoint);
while (true)
{
try
{
data = server.Receive(ref inPoint);
}
catch (Exception err)
{
Console.WriteLine("Blaster.translater: recieve data error: " + err.Message);
client.Close();
return;
}
string json = Encoding.ASCII.GetString(data);
Console.WriteLine(json);
Packet p = JsonConvert.DeserializeObject<Packet>(json);
}
}
}
}

Socket Error 10054 : Error Handling Issue

Eveyone.
How to resolve the Error code 10054 ? There are some description about this error. Here is my full source code for communication. I want to know whether my code is ok or not.
WSAECONNRESET10054 Connection reset by peer. An existing connection
was forcibly closed by the remote host. This normally results if the
peer application on the remote host is suddenly stopped, the host is
rebooted, the host or remote network interface is disabled, or the
remote host uses a hard close (see setsockopt for more information on
the SO_LINGER option on the remote socket). This error may also result
if a connection was broken due to keep-alive activity detecting a
failure while one or more operations are in progress. Operations that
were in progress fail with WSAENETRESET. Subsequent operations fail
with WSAECONNRESET.
Full Source Code
using System;
using System.Net;
using System.Net.Sockets;
using System.Reflection;
using System.Threading;
using LogManager;
namespace CoreUnitPlatform
{
public class SocketCommCoreUnit
{
#region property
private volatile bool _shouldStop;
private LogWriter log = LogWriter.Instance;
private bool m_bSocketConnected = false;
private Socket m_clientSocket = null;
private SocketCommType m_connectedSockType;
private EventHandlerDataReceived m_evtHandlerDataReceived;
private EventHandlerSocketConnected m_evtHandlerSocketConnected;
private EventHandlerSocketConnectedFailed m_evtHandlerSocketConnectedFailed;
private EventHandlerSocketDisconnected m_evtHandlerSocketDisconnected;
private IPAddress m_IPAddress;
private IPEndPoint m_IPEndPoint;
private int m_portNo;
private Socket m_serverSocket = null;
private Thread m_threadConnectSocket = null;
private string Name = string.Empty;
#endregion
#region constructor
public SocketCommCoreUnit()
{
this.Name = "SocketCommCoreUnit";
Instance();
}
#endregion
#region delegatge
public delegate void EventHandlerDataReceived(string msg);
public delegate void EventHandlerSocketConnected();
public delegate void EventHandlerSocketConnectedFailed();
public delegate void EventHandlerSocketDisconnected();
public enum SocketCommType { SERVER, CLIENT };
public bool SocketConnected
{
get { lock (this) { return m_bSocketConnected; } }
set { lock (this) { m_bSocketConnected = value; } }
}
#endregion
#region public
public void ConnectSocketProc()
{
while (!_shouldStop)
{
try
{
if (SocketConnected == false)
{
if (m_connectedSockType == SocketCommType.SERVER)
{
m_clientSocket = m_serverSocket.Accept(); // If a client is connected, wait for data from client
m_evtHandlerSocketConnected();
SocketConnected = true;
}
else
{
m_clientSocket.Connect(m_IPAddress, m_portNo);
if (m_clientSocket.Connected == true)
{
m_evtHandlerSocketConnected();
SocketConnected = true;
}
}
}
else
{
try
{
byte[] buffer = new byte[1024];
int readBytes = this.m_clientSocket.Receive(buffer);
if (readBytes == 0)
{
this.reConnect();
}
else
{
string received = System.Text.Encoding.ASCII.GetString(buffer);
m_evtHandlerDataReceived(received);
}
}
catch (SocketException sex)
{
if (sex.NativeErrorCode.Equals(10054))
{
log.AddErrorLog(this.Name, MethodBase.GetCurrentMethod().Name, string.Format("Error Occured [{0}]: MESASGE[{1}]\r\nSOURCE[{2}]\r\nTRACE[{3}]", sex.NativeErrorCode, sex.Message, sex.Source, sex.StackTrace));
this.reConnect();
}
}
}
}
catch
{
m_evtHandlerSocketConnectedFailed();
}
Thread.Sleep(100);
}
}
public void Initialize(string IP, int port, SocketCommType sockType, EventHandlerDataReceived evtHandlerDataReceived, EventHandlerSocketConnected evtHandlerDataConnected, EventHandlerSocketDisconnected evtHandlerSocketDisconnected, EventHandlerSocketConnectedFailed evtHandlerSocketConnectedFailed)
{
m_connectedSockType = sockType;
m_evtHandlerDataReceived = evtHandlerDataReceived;
m_evtHandlerSocketDisconnected = evtHandlerSocketDisconnected;
m_evtHandlerSocketConnected = evtHandlerDataConnected;
m_evtHandlerSocketConnectedFailed = evtHandlerSocketConnectedFailed;
m_portNo = port;
m_IPAddress = IPAddress.Parse(IP);
m_IPEndPoint = new IPEndPoint(m_IPAddress, m_portNo);
if (sockType == SocketCommType.SERVER)
{
OpenServer();
}
else
{
OpenClient();
}
}
public void Instance()
{
}
public void OpenClient()
{
try
{
#if _NO_USE_SOCKET
#else
RunClientSocket();
#endif
}
catch (System.Exception ex)
{
log.AddErrorLog(this.Name, MethodBase.GetCurrentMethod().Name, string.Format("Error Occured: MESASGE[{0}]\r\nSOURCE[{1}]\r\nTRACE[{2}]", ex.Message, ex.Source, ex.StackTrace));
}
}
public void OpenServer()
{
try
{
#if _NO_USE_SOCKET
#else
RunServerSocket();
#endif
}
catch (System.Exception ex)
{
log.AddErrorLog(this.Name, MethodBase.GetCurrentMethod().Name, string.Format("Error Occured: MESASGE[{0}]\r\nSOURCE[{1}]\r\nTRACE[{2}]", ex.Message, ex.Source, ex.StackTrace));
}
}
public void Release()
{
try
{
if (this.m_clientSocket != null && this.m_clientSocket.Connected)
{
SocketConnected = false;
m_evtHandlerSocketDisconnected();
this.m_clientSocket.Shutdown(SocketShutdown.Both);
this.m_clientSocket.Close();
}
if (m_serverSocket != null)
{
m_serverSocket.Close();
}
if ((m_threadConnectSocket != null) && (m_threadConnectSocket.IsAlive == true))
{
Thread.Sleep(1);
RequestStop();
SocketConnected = false;
m_threadConnectSocket.Abort();
m_threadConnectSocket.Join();
}
}
catch (System.Exception ex)
{
log.AddErrorLog(this.Name, MethodBase.GetCurrentMethod().Name, string.Format("Error Occured: MESASGE[{0}]\r\nSOURCE[{1}]\r\nTRACE[{2}]", ex.Message, ex.Source, ex.StackTrace));
}
}
public void RequestStop()
{
_shouldStop = true;
}
public void RunClientSocket()
{
m_clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
ConfigureTcpSocket(m_clientSocket, SocketCommType.CLIENT);
m_threadConnectSocket = new Thread(new ThreadStart(ConnectSocketProc));
m_threadConnectSocket.Start();
}
public void RunServerSocket()
{
m_serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
m_serverSocket.Bind(m_IPEndPoint);
m_serverSocket.Blocking = true; // The server socket is working in blocking mode
ConfigureTcpSocket(m_serverSocket, SocketCommType.SERVER);
m_serverSocket.Listen(1);
m_threadConnectSocket = new Thread(new ThreadStart(ConnectSocketProc));
m_threadConnectSocket.Start();
}
public void Send(byte[] msg)
{
#if _NO_USE_SOCKET
#else
if (SocketConnected == false)
{
throw new Exception("SOCKET_NOT_CONNECT_BEFORE_SEND_DATA;");
}
try
{
m_clientSocket.Send(msg);
}
catch (System.Exception ex)
{
SocketConnected = false;
m_evtHandlerSocketDisconnected();
log.AddErrorLog(this.Name, MethodBase.GetCurrentMethod().Name, string.Format("Error Occured: MESASGE[{0}]\r\nSOURCE[{1}]\r\nTRACE[{2}]", ex.Message, ex.Source, ex.StackTrace));
}
#endif
}
#endregion
#region private
private void ConfigureTcpSocket(Socket tcpSocket, SocketCommType socketCommType)
{
//// Don't allow another socket to bind to this port.
//tcpSocket.ExclusiveAddressUse = true;
//// The socket will linger for 10 seconds after
//// Socket.Close is called.
//tcpSocket.LingerState = new LingerOption(true, 10);
// Disable the Nagle Algorithm for this tcp socket.
tcpSocket.NoDelay = true;
//if (socketCommType == SocketCommType.CLIENT)
//{
// tcpSocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.DontLinger, false);
// tcpSocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
// //tcpSocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout, 3000);
// //tcpSocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.SendTimeout, 3000);
// // Set the receive buffer size to 8k
// tcpSocket.ReceiveBufferSize = 2048;
// // Set the send buffer size to 8k.
// tcpSocket.SendBufferSize = 2048;
//}
//// Set the receive buffer size to 8k
//tcpSocket.ReceiveBufferSize = 1024;
// Set the timeout for synchronous receive methods to
// 1 second (1000 milliseconds.)
//tcpSocket.ReceiveTimeout = 1000;
//// Set the send buffer size to 8k.
//tcpSocket.SendBufferSize = 1024;
// Set the timeout for synchronous send methods
// to 1 second (1000 milliseconds.)
//tcpSocket.SendTimeout = 1000;
//// Set the Time To Live (TTL) to 42 router hops.
//tcpSocket.Ttl = 42;
}
private void ConfigureTcpSocket(Socket tcpSocket)
{
//// Don't allow another socket to bind to this port.
//tcpSocket.ExclusiveAddressUse = true;
//// The socket will linger for 10 seconds after
//// Socket.Close is called.
//tcpSocket.LingerState = new LingerOption(true, 10);
// Disable the Nagle Algorithm for this tcp socket.
tcpSocket.NoDelay = true;
//// Set the receive buffer size to 8k
//tcpSocket.ReceiveBufferSize = 8192;
// Set the timeout for synchronous receive methods to
// 1 second (1000 milliseconds.)
//tcpSocket.ReceiveTimeout = 1000;
//// Set the send buffer size to 8k.
//tcpSocket.SendBufferSize = 8192;
// Set the timeout for synchronous send methods
// to 1 second (1000 milliseconds.)
//tcpSocket.SendTimeout = 1000;
//// Set the Time To Live (TTL) to 42 router hops.
//tcpSocket.Ttl = 42;
}
private void reConnect()
{
try
{
SocketConnected = false;
m_evtHandlerSocketDisconnected();
m_clientSocket.Disconnect(true);
log.AddSystemLog(this.Name, MethodBase.GetCurrentMethod().Name, string.Format("Try Re-Connection..."));
if (m_connectedSockType == SocketCommType.SERVER)
{
}
else
{
m_clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
}
}
catch (System.Exception exc)
{
log.AddErrorLog(this.Name, MethodBase.GetCurrentMethod().Name, string.Format("Error Occured: MESASGE[{0}]\r\nSOURCE[{1}]\r\nTRACE[{2}]", exc.Message, exc.Source, exc.StackTrace));
}
}
#endregion
}
}
I made a (IMOHO) nice post about async sockets here, It has some pseudo code about server/client sockets.
Article: Unable to read data correctly from .Net socket in C#
I think the code of Asynchronous example is great.

Categories