protected override void ClientConnected(int clientNumber)
{
Traces.NntpServerTraceEvent(TraceEventType.Verbose, string.Format("[Client {0}] ClientConnected", clientNumber));
lock (_clients)
{
_clients.Add(clientNumber, new Client(clientNumber));
}
// log connection
PerfCounters.IncrementCounter(PerfCounterName.CurrentConnections);
PerfCounters.IncrementCounter(PerfCounterName.TotalConnections);
if (_postingAllowed)
{
SendData(GeneralResponses.ServerReadyPostingAllowed, clientNumber);
}
else
{
SendData(GeneralResponses.ServerReadyPostingNotAllowed, clientNumber);
}
}
protected override void DataReceived(string data, int clientNumber)
{
try
{
Stopwatch sw = new Stopwatch();
sw.Start();
NntpCommand nntpCommand = null;
var client = GetClient(clientNumber);
string response;
if (client == null)
{
throw new Exception("Client object for [" + clientNumber + "] is not available");
}
//LogMessage(clientNumber, client.AuthenticatedClientUsername, data, NO_LOGGING, string.Empty);
//LogMessage(clientNumber, string.Empty, data, NO_LOGGING, string.Empty);
// log receive data size
PerfCounters.IncrementCounterBy(PerfCounterName.BytesReceived, data.Length);
bool parseCommand = false;
string additionalData = string.Empty;
if (client.PreviousCommand == Command.POST)
{
Traces.NntpServerTraceEvent(TraceEventType.Verbose, client, "DataReceived: Client is posting data");
//System.Diagnostics.Debug.WriteLine("Buffer: {0}", client.Buffer);
//System.Diagnostics.Debug.WriteLine("Recv: {0}", data);
// client is posting data,
// keep buffering until dotted terminator reached
string postData = data;
/*
* string ascSeq = string.Empty;
* for (int i = 0; i < postData.Length; i++)
* {
* ascSeq += (int)postData[i] + " ";
* }
* //System.Diagnostics.Trace.WriteLine("ascSeq - " + ascSeq);
*/
// Append the data to the internal buffer
client.Buffer.Append(postData);
// Then extract (at least) the last 5 chars (or min the number of currently received bytes) to determine the termination...
string lastChars = string.Empty;
if (client.Buffer.Length >= 5)
{
int len = Math.Max(postData.Length, 5);
lastChars = client.Buffer.ToString(client.Buffer.Length - len, len);
}
// Check for "termination" signal...
if (lastChars.IndexOf("\r\n.\r\n") >= 0)
{
//System.Diagnostics.Trace.WriteLine("Termination sequence sent");
var buf = client.Buffer.ToString();
// extract post data up to the dot terminator
client.Buffer = new StringBuilder(buf.Substring(0, buf.IndexOf("\r\n.\r\n")));
// grab any data received after the terminator
additionalData = buf.Substring(buf.IndexOf("\r\n.\r\n") + 5);
// flag to say we wish to process the received data
parseCommand = true;
}
//else if (lastChars.StartsWith(".\r\n"))
//{
// // WHAT does this mean???
// // no post data in this request
// postData = string.Empty;
// // grab any data received after the terminator
// additionalData = data.Substring(3);
// // flag to say we wish to process the received data
// parseCommand = true;
//}
//client.Buffer.Append(postData);
if (parseCommand)
{
//System.Diagnostics.Trace.WriteLine("Posting article");
// create a new command
nntpCommand =
new NntpCommandPostData
{
Provider = _dataProvider
};
// TODO: nntpCommand.ClientUsername = client.AuthenticatedClientUsername;
// log command
PerfCounters.IncrementCounter(PerfCounterName.TotalNntpCommandPostData);
// ensure command executed in context of authenticated user
// TODO: client.ImpersonateClient();
Traces.NntpServerTraceEvent(TraceEventType.Verbose, client, "Received: {0}: {1}", nntpCommand.Command, client.Buffer.ToString());
// post the article
response = nntpCommand.Parse(client.Buffer.ToString(), null, client);
Traces.NntpServerTraceEvent(TraceEventType.Verbose, client, "Response: {0}", response);
// revert to service security context
// TODO: client.RevertImpersonation();
// send back success/fail message
SendData(response, clientNumber);
PerfCounters.IncrementCounter(PerfCounterName.CommandsProcessedPerSecond);
// clear down buffer & reset command
client.Buffer = new StringBuilder();
client.PreviousCommand = Command.NOTRECOGNISED;
nntpCommand = null;
}
}
else
{
//System.Diagnostics.Trace.WriteLine("Client not posting data");
// client is not posting data,
// wait until CR-LF pair is reached
string postData = data;
if (postData.IndexOf("\r\n") >= 0)
{
//System.Diagnostics.Trace.WriteLine("CR-LF pair received");
// extract up to end of line
postData = postData.Substring(0, postData.IndexOf("\r\n"));
// obtain further data (should not normally be present)
additionalData = data.Substring(data.IndexOf("\r\n") + 2);
parseCommand = true;
}
client.Buffer.Append(postData);
if (parseCommand)
{
// determine type of command and extract parameters
nntpCommand = ClassifyCommand(client);
// clear down buffer
client.Buffer = new StringBuilder();
}
}
if (nntpCommand != null)
{
// ensure command executed in context of authenticated user
// TODO: client.ImpersonateClient();
// execute the command
var dataSendInAction = false;
Action <string> streamWriter = p =>
{
SendData(p, client.ClientNumber);
dataSendInAction = true;
Traces.NntpServerTraceEvent(TraceEventType.Verbose, client, "Received: Response: {0}", p);
};
Traces.NntpServerTraceEvent(TraceEventType.Verbose, client, "Received: Command: {0}, Parameters: {1}", nntpCommand.Command, client.CommandParameters);
response = nntpCommand.Parse(client.CommandParameters, streamWriter, client);
// revert to service security context
// TODO: client.RevertImpersonation();
// log command
PerfCounterName perfCounterNameForCommand = GetTotalCounterFromCommand(client.PreviousCommand);
PerfCounters.IncrementCounter(perfCounterNameForCommand);
// client attempting to authenticate more than once
// then re-authenticate
if (client.PreviousCommand == Command.AUTHINFO &&
nntpCommand.AuthToken == null)
{
if (client.Authenticated)
{
// TODO: client.AuthServerContext.Dispose();
// TODO: client.AuthServerContext = null;
client.Authenticated = false;
}
}
// steps 2 and 3 of the authentication process
if (client.PreviousCommand == Command.AUTHINFO &&
nntpCommand.AuthToken != null)
{
try
{
// TODO: ServerCredential serverCredential = new ServerCredential(Credential.Package.NTLM);
//if (client.AuthServerContext == null)
//{
// client.AuthServerContext = new ServerContext(serverCredential, nntpCommand.AuthToken);
// response = response.Replace("<token>", Convert.ToBase64String(client.AuthServerContext.Token));
//}
//else
//{
//client.AuthServerContext.Accept(nntpCommand.AuthToken);
client.Authenticated = true;
response = GeneralResponses.AuthenticationAccepted;
// PerfCounters.IncrementCounter(PerfCounterName.ResponseAuthenticationAccepted);
//}
}
catch (Exception ex)
{
// error during authentication (e.g. access denied)
// return response to client
Traces.NntpServerTraceEvent(TraceEventType.Critical, client, "Failed to authenticate: {0}", Traces.ExceptionToString((ex)));
// TODO: client.AuthServerContext.Dispose();
// TODO: client.AuthServerContext = null;
client.Authenticated = false;
response = GeneralResponses.AccessDenied;
PerfCounters.IncrementCounter(PerfCounterName.ResponseAccessDenied);
}
}
//// if user not logged in, send back authenticated required
//// message
//if (client.PreviousCommand != Command.MODE &&
// client.PreviousCommand != Command.AUTHINFO &&
// (!client.Authenticated ||
// (client.Authenticated &&
// client.AuthenticatedClientUsername.Length == 0)))
//{
// response = GeneralResponses.AuthenticationRequired;
// PerfCounters.IncrementCounter(PerfCounterName.ResponseAuthenticationRequired);
//}
// send response to client
if (dataSendInAction == false)
{
if (string.IsNullOrEmpty(response) == false)
{
SendData(response, clientNumber);
Traces.NntpServerTraceEvent(TraceEventType.Verbose, client, "Received: Response: {0}", response);
PerfCounters.IncrementCounter(PerfCounterName.CommandsProcessedPerSecond);
// log sent data size
PerfCounters.IncrementCounterBy(PerfCounterName.BytesSent, response.Length);
}
else
{
throw new Exception("No data returned from parsed command [" + client.PreviousCommand + "]");
}
}
// adjust client state after command execution
switch (client.PreviousCommand)
{
case Command.POST:
if (nntpCommand.PostCancelled)
{
Trace.WriteLine("Posting is not allowed, reset status on client object");
client.PreviousCommand = Command.NOTRECOGNISED;
}
break;
case Command.QUIT:
DisconnectClient(clientNumber);
break;
}
}
// continue processing if needed
// additional commands may follow the command
// or post data just processed
if (additionalData.Trim().Length > 0)
{
DataReceived(additionalData, clientNumber);
}
sw.Stop();
lock (_perfCounterLock)
{
PerfCounters.IncrementCounterBy(PerfCounterName.AverageProcessingTime, sw.ElapsedTicks);
PerfCounters.IncrementCounter(PerfCounterName.AverageProcessingTimeBase);
}
}
catch (Exception ex)
{
Traces.NntpServerTraceEvent(TraceEventType.Critical, "[Client {0}] DataReceived failed: {1}", clientNumber, Traces.ExceptionToString(ex));
if (clientNumber > 0)
{
PerfCounters.IncrementCounter(PerfCounterName.ResponseProgramFault);
// INFO: Reply with more specific error message:
//if (DetailedErrorResponse)
//{
var resp = string.Format(
"503 program fault - command not performed {0}\r\n",
GetErrorResponseFromExeption(ex));
SendData(resp, clientNumber);
//}
//else
//{
// SendData(GeneralResponses.ProgramFault, clientNumber);
//}
}
}
}