/// <summary>
/// Runs when data is received from a client. Parses the information and sends it off
/// to a method to handle the information.
/// </summary>
/// <param name="asyncResult">Result containing the client info</param>
public void DataReceivedCallback(IAsyncResult asyncResult)
{
ClientInfo client = (ClientInfo)asyncResult.AsyncState;
try
{
var readBytes = _usingSsl ? client._clientSslStream.EndRead(asyncResult) : client.ClientSocket().EndReceive(asyncResult);
client.ClientStringBuilder().Append(Encoding.ASCII.GetString(client.DataBuffer(), 0, readBytes));// Add on the new data
string currentData = client.ClientStringBuilder().ToString();
int position;
while ((position = currentData.IndexOf("<EOF>", StringComparison.Ordinal)) != -1)// Keep going until we don't have any more commands
{
string command = currentData.Substring(0, position);
Console.WriteLine($"<{client._username}> {command}");
currentData = currentData.Remove(0, position + 5); // Remove the command from the currentData string
HelperMethods.CommandHandler(command, client); // Handle the command
}
client.ClientStringBuilder().Clear(); // We used the data in the string builder so now we can clear it
client.ClientStringBuilder().Append(currentData); // There still might be some data left so we add it back in
client.BeginReceiveData(); // Continue receiving data
}
catch (ObjectDisposedException)
{
Console.WriteLine("DataReceivedCallback(): Socket was closed before finishing receive");
}
catch (SocketException se)
{
if (se.ErrorCode == 10054)// Connection reset by peer.
{
Console.WriteLine($"DataReceivedCallback(): Client went offline");
}
else
{
Console.WriteLine($"DataReceivedCallback(): {se.Message} Error Code: {se.ErrorCode}");
}
HelperMethods.RemoveClientFromAll(client);
}
catch (IOException ioe)
{
if (ioe.InnerException is SocketException se)
{
if (se.ErrorCode == 10054)// Connection reset by peer.
{
Console.WriteLine($"DataReceivedCallback(): Client went offline");
}
}
else
{
Console.WriteLine($"DataReceivedCallback(): {ioe.Message}");
}
HelperMethods.RemoveClientFromAll(client);
}
catch (Exception e)
{
Console.WriteLine($"DataReceivedCallbackSsl(): {e.Message}");
if (e.InnerException != null)
{
Console.WriteLine($"DataReceivedCallbackSsl(): {e.InnerException}");
}
HelperMethods.RemoveClientFromAll(client);
}
}
/// <summary>
/// Runs on a new client connection, and sets a client id and adds to list of clients.
/// </summary>
/// <param name="asyncResult">Result from connection containing socket to client</param>
public static void ClientConnectCallback(IAsyncResult asyncResult)
{
try
{
Socket clientSocket = Globals.Listener.EndAccept(asyncResult);
NetworkStream networkStream = new NetworkStream(clientSocket);
SslStream sslStream = new SslStream(networkStream, false);
// Authenticate the server but don't require the client to authenticate.
try
{
sslStream.AuthenticateAsServer(Globals.ServerCertificate, false,
true);
// Display the properties and settings for the authenticated stream.
HelperMethods.DisplaySecurityLevel(sslStream);
HelperMethods.DisplaySecurityServices(sslStream);
HelperMethods.DisplayCertificateInformation(sslStream);
HelperMethods.DisplayStreamProperties(sslStream);
// Set timeouts to 5 seconds.
sslStream.ReadTimeout = 5000;
sslStream.WriteTimeout = 5000;
}
catch (AuthenticationException e)
{
Console.WriteLine($"Exception: {e.Message}");
if (e.InnerException != null)
{
Console.WriteLine($"Inner exception: {e.InnerException.Message}");
}
Console.WriteLine("Authentication failed - closing the connection.");
sslStream.Close();
clientSocket.Close();
Globals.Listener.BeginAccept(ClientConnectCallback, null);// keep listening
return;
}
catch (Exception e)
{
Console.WriteLine($"Exception: {e.Message}");
sslStream.Close();
clientSocket.Close();
Globals.Listener.BeginAccept(ClientConnectCallback, null);// keep listening
return;
}
byte[] clientId = new byte[10];
Globals.Random.NextBytes(clientId);
string idString = clientId.Aggregate("", (current, idByte) => current + idByte);
// Keep trying until we get a username that isn't taken
while (HelperMethods.UsernameTaken(idString))
{
Globals.Random.NextBytes(clientId);
idString = clientId.Aggregate("", (current, idByte) => current + idByte);
}
ClientInfo newClient = new ClientInfo(clientSocket, sslStream, networkStream);
newClient.SetUsername(idString);// Set the default username to the randomly generated byte id
Globals.ClientList.Add(newClient);
Console.WriteLine($"Client {newClient.GetUsername()} connected");
newClient.BeginReceiveData();
Globals.Listener.BeginAccept(ClientConnectCallback, null);
}
catch (ObjectDisposedException)
{
Console.WriteLine("ClientConnectCallback(): Object already disposed");
}
catch (SocketException se)
{
Console.WriteLine(se.Message);
}
}
