// Method: server listening to client request.
public void StartListening()
{
// Establish the local endpoint for the socket
// using the DNS name of the local computer.
_ipHostInfo = Dns.GetHostEntry(Dns.GetHostName());
_ipAddress = _ipHostInfo.AddressList[0];
_localEndPoint = new IPEndPoint(_ipAddress, 3000);
// Proxy endpoint.
_proxyEndPoint = new IPEndPoint(_ipAddress, 4000);
// New socket to connect with proxy.
Socket proxySocket = new Socket(_ipAddress.AddressFamily,
SocketType.Stream, ProtocolType.Tcp);
// Create a TCP/IP socket to listen for connections.
Socket listener = new Socket(_ipAddress.AddressFamily,
SocketType.Stream, ProtocolType.Tcp);
try
{
// Bind the socket to the local endpoint and
// listen for incoming connections.
listener.Bind(_localEndPoint);
listener.Listen(100);
// Create a new thread just for checking clients' status.
Thread checkThread = new Thread(TestClientStatus);
checkThread.Name = "check thread";
checkThread.IsBackground = true;
checkThread.Start();
// Name main thread.
Thread.CurrentThread.Name = "main thread";
// Connect with proxy
proxySocket.Connect(_proxyEndPoint);
_proxyConnection = new ClientConnection(proxySocket);
// Make a new thread to maintain proxy connection.
Thread proxyThread = new Thread(ProxyCommunicate);
proxyThread.Name = "proxy thread";
proxyThread.IsBackground = true;
proxyThread.Start();
// Add main hall to list of chat room.
_localCR.Add(_mainHall);
while (true)
{
Console.WriteLine("Waiting for a connection...");
// Start an asynchronous socket to handle client request.
// Program will pause here until request accepted.
Socket handler = listener.Accept();
// Once accepted, create a ClientConnection object
// and a UserInfo object to contain that particular
// user information.
ClientConnection clientState = new ClientConnection(handler);
UserInfo newUser = new UserInfo(clientState);
// Assign name for connected client.
newUser.UserName = "******" + _clientCount.ToString();
clientState.GetUser(newUser);
// Update server's client list.
_userList.Add(newUser);
// Add user to main hall.
_mainHall.AddUser(newUser);
// Update user's current room = main hall.
newUser.CurrentChatRoom = _mainHall;
_clientCount++;
// Create new thread to asynchronously handle client request.
Thread clientThread = new Thread(RequestHandler);
clientThread.Start(clientState);
// Name the thread after client name.
clientThread.Name = newUser.UserName;
// Set the thread to be running in background.
clientThread.IsBackground = true;
// This thread (main thread) will pause here until the client
// thread created above signal that it has created successfully.
_mainThread.WaitOne();
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
// Informing proxy that this server is going offline.
_packetSent.title = MsgTitle.server_off.ToString();
_packetSent.sender = this.ServerName;
_packetSent.content = null;
foreach (var entry in _peerServerDict.Values)
{
_packetSent.IP = entry.ClientSocket.LocalEndPoint.ToString();
entry.sendMsg(_packetSent);
}
_proxyConnection.sendMsg(_packetSent);
// Shutdown listening socket.
listener.Shutdown(SocketShutdown.Both);
listener.Close();
}
Console.WriteLine("\nPress ENTER to continue...");
Console.Read();
}
// Method: maintaining communication with proxy.
// Executed on separated thread.
private void ProxyCommunicate()
{
// Inform proxy that this server is on.
_packetSent.title = MsgTitle.server_on.ToString();
_packetSent.time = _now;
// use local EP of this server so that proxy can send this EP
// to other servers, then they can connect to this server.
_packetSent.IP = _localEndPoint.ToString();
_packetSent.content = null;
_packetSent.sender = this.ServerName;
_proxyConnection.sendMsg(_packetSent);
Console.WriteLine("proxy is online");
bool notDone = true;
try
{
// Begin receiving info from proxy.
while (notDone)
{
int bytesRec = _proxyConnection.ClientSocket.Receive(_proxyConnection.ReceiveBuffer);
string stringRec = Encoding.ASCII.GetString(_proxyConnection.ReceiveBuffer, 0, bytesRec);
var serializer = new JavaScriptSerializer();
var serializedResult = serializer.Deserialize <Packet>(stringRec);
_packetReceived = serializedResult;
//Console.WriteLine(_packetReceived.content);
//Console.WriteLine(_packetReceived.IP);
//Console.WriteLine(_packetReceived.sender);
//Console.WriteLine(_packetReceived.title);
// When proxy is checking whether this server is still online.
if (_packetReceived.title.Equals(MsgTitle.are_you_online.ToString()))
{
// Inform proxy that this server is still online.
_packetSent.title = MsgTitle.online.ToString();
_packetSent.time = _now;
_packetSent.IP = _proxyConnection.ClientSocket.LocalEndPoint.ToString();
_packetSent.content = "online";
_packetSent.sender = this.ServerName;
_proxyConnection.sendMsg(_packetSent);
}
// Proxy inform that there is a new server online.
else if (_packetReceived.title.Equals(MsgTitle.server_on.ToString()))
{
// content will be name of server online
// IP is the IP of that server.
// create new thread and call the servercommunicate function
// create/update server ClientConnection
//Console.WriteLine("sender is " + _packetReceived.sender);
// New socket to connect with proxy.
Socket serverSocket = new Socket(_ipAddress.AddressFamily,
SocketType.Stream, ProtocolType.Tcp);
// Generate endpoint for server.
IPEndPoint remoteEP = createIPEndPoint(_packetReceived.IP);
serverSocket.Connect(remoteEP);
// Create new instance of ClientConnection to hold info.
ClientConnection newServerConn = new ClientConnection(serverSocket);
UserInfo serverInfo = new UserInfo(newServerConn);
newServerConn.GetUser(serverInfo);
newServerConn.Name = _packetReceived.content;
// Add this server to server dict.
//Console.WriteLine("content " + _packetReceived.content);
_peerServerDict[_packetReceived.content] = newServerConn;
// Make a new thread to maintain servers connection.
Thread serverThread = new Thread(ServerCommunicate);
serverThread.Name = newServerConn.Name;
//Console.WriteLine(serverThread.Name);
serverThread.IsBackground = true;
serverThread.Start(newServerConn);
}
else if (_packetReceived.title.Equals(MsgTitle.server_off.ToString()))
{
// Content is the name of the server.
if (_peerServerDict.ContainsKey(_packetReceived.content))
{
_peerServerDict.Remove(_packetReceived.content);
Console.WriteLine("Server " + _packetReceived.content + " is offline");
}
}
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
notDone = false;
}
}