/// <summary>
/// Call to disconnect from the server.
/// </summary>
/// <remarks>Always call disconnect before exiting the program. Failure to do so could cause a zombie thread.
/// Also note that this sets the <see cref="Client.ClientNetwork.Username">Username</see> to blank and makes <see cref="Client.ClientNetwork.Connected">Connected</see> false.</remarks>
/// <example>Always call this function on exit.
/// <code>protected override void Dispose( bool disposing )
/// {
/// // Always call this before exiting the program
/// ClientNetwork.Disconnect();
/// }</code></example>
public static void Disconnect(bool forced)
{
try
{
// Try to close the stream
connectionStream.Close();
}
catch
{}
username = "";
connected = false;
if (forced)
{
Network.Header logoffHeader = new SDCSCommon.Network.Header();
logoffHeader.DataType = Network.DataTypes.Logout;
logoffHeader.Encrypted = false;
logoffHeader.Length = 0;
DataReceivedEventArgs e = new DataReceivedEventArgs();
e.Header = logoffHeader;
e.Data = System.Text.UnicodeEncoding.Unicode.GetBytes("Lost connection to server");
DataReceived(null, e);
}
try
{
// Try to kill the thread
listeningThread.Abort();
}
catch
{}
}
/// <summary>
/// Sends the keepAlive signal to check if the network connection is still active
/// </summary>
private static void sendKeepAlive()
{
Network.Header pingHead = new SDCSCommon.Network.Header();
pingHead.DataType = Network.DataTypes.Ping;
pingHead.Encrypted = false;
pingHead.FromID = 0;
pingHead.Length = 0;
pingHead.ToID = -1;
SendData(Network.headerToBytes(pingHead));
}
/// <summary>
/// Function for the connection watching thread to live in. Basically is a message pump for the network
/// </summary>
private void connectionWatcherFunc()
{
// Records the last time a byte was received so we can check for a read timeout
System.DateTime lastRead;
// First send the random code for the client
Network.Header sendHead = new SDCSCommon.Network.Header();
sendHead.DataType = Network.DataTypes.RandomPassCode;
sendHead.FromID = -1;
sendHead.ToID = 0;
sendHead.Length = 32;
// Create a random 32 byte unicode string
randomCode = new byte[32];
Random rand = new Random();
rand.NextBytes(randomCode);
// And send it to the client
sendData(Network.headerToBytes(sendHead), randomCode);
// Now loop forever
while (true)
{
// Each while loop continually checks if the server is shutting down.
// This is to make sure that we don't end up with zombie threads.
while (conn.stream.DataAvailable == false)
{
if (ServerNetwork.ShuttingDown)
return;
if (BuddyListData.Count != 0)
sendBuddyListData();
if (System.DateTime.Now - lastActivity > TimeSpan.FromMilliseconds(KEEP_ALIVE_TIME))
sendKeepAlive();
Thread.Sleep(100);
}
byte[] headerBuffer = new byte[Network.HEADER_SIZE];
lastRead = System.DateTime.Now;
for (int i = 0; i < headerBuffer.Length; i++)
{
while (conn.stream.DataAvailable == false)
{
if (frmServer.ShuttingDown || (System.DateTime.Now - lastRead) > System.TimeSpan.FromMilliseconds(MAX_READ_WAIT_TIME))
return;
Thread.Sleep(100);
}
headerBuffer[i] = (byte)conn.stream.ReadByte();
lastRead = System.DateTime.Now;
}
Network.Header head = Network.bytesToHeader(headerBuffer);
// This is to prevent a user from spoofing themselves as another user
head.FromID = conn.userID;
// Read in exactly the amount of data sent
byte[] data = new byte[head.Length];
lastRead = System.DateTime.Now;
for (int i = 0; i < head.Length; i++)
{
while (conn.stream.DataAvailable == false)
{if (frmServer.ShuttingDown || (System.DateTime.Now - lastRead) > System.TimeSpan.FromMilliseconds(MAX_READ_WAIT_TIME))
return;
Thread.Sleep(100);}
data[i] = (byte)conn.stream.ReadByte();
lastRead = System.DateTime.Now;
}
// We don't want to allow someone to do anything but log in until they are logged in
if ((loggedIn && head.DataType != Network.DataTypes.LoginInformation) || head.DataType == Network.DataTypes.LoginInformation || head.DataType == Network.DataTypes.Ping)
{
switch (head.DataType)
{
case Network.DataTypes.InstantMessage: // Instant message data
for (int i = 0; i < ServerNetwork.netStreams.Count; i++)
{
if (((ServerNetwork.connection)ServerNetwork.netStreams[i]).userID == head.ToID)
{
((ServerNetwork.connection)ServerNetwork.netStreams[i]).watchingClass.sendData(Network.headerToBytes(head), data);
}
}
break;
case Network.DataTypes.WhiteBoard: // Whiteboard drawing information
break;
case Network.DataTypes.LoginInformation: // Initial login
// We receive a double hased password from the client. We store the single hash in the user database.
// First we convert the received username and double hash in to unicode strings.
int usernameLength = BitConverter.ToInt32(data,0);
string username = System.Text.UnicodeEncoding.Unicode.GetString(data, 4, usernameLength);
string password = System.Text.UnicodeEncoding.Unicode.GetString(data, 4 + usernameLength, data.Length - (4 + usernameLength));
Network.Header confirmHead = new SDCSCommon.Network.Header();
confirmHead.DataType = Network.DataTypes.LoginStatus;
confirmHead.FromID = -1;
confirmHead.Length = 4;
// This statement performs the second hash on the stored password and compares it with the password received from
// the client.
if (CryptoFunctions.getMD5Hash(String.Concat(ServerDatabase.getUserPass(username), System.Text.UnicodeEncoding.Unicode.GetString(randomCode))) == password)
{ // Login successful
conn.userID = ServerDatabase.getUserID(username);
conn.username = username;
// Make sure we are only logged in from one place at a time
lock (ServerNetwork.netStreams.SyncRoot)
{
for (int i = ServerNetwork.netStreams.Count - 1; i >= 0; i--)
if (((ServerNetwork.connection)ServerNetwork.netStreams[i]).userID == conn.userID && ((ServerNetwork.connection)ServerNetwork.netStreams[i]).watchingClass.loggedIn)
((ServerNetwork.connection)ServerNetwork.netStreams[i]).watchingClass.Shutdown();
}
confirmHead.ToID = conn.userID;
// Send the Login OK message to let the client know they're authenticated
sendData(Network.headerToBytes(confirmHead), BitConverter.GetBytes(Network.LoginOK));
loggedIn = true;
// Let everyone know that the user is now online
conn.userState = SDCSCommon.Network.UserState.Online;
ServerNetwork.notifyBuddyStatus(conn.userID, conn.username, Network.UserState.Online);
ServerNetwork.refreshBuddyList(conn);
}
else
{ // Login failed
confirmHead.ToID = 0;
sendData(Network.headerToBytes(confirmHead), BitConverter.GetBytes(Network.LoginBad));
Shutdown();
}
break;
case Network.DataTypes.Logout:
Shutdown();
break;
default:
break;
}
}
else
Shutdown();
lastActivity = System.DateTime.Now;
}
}
