/// <summary>
/// Redirect recived query from current server to other.
/// </summary>
/// <param name="tc">Server's transmission controller.</param>
/// <param name="query">Query received from client.</param>
public static void QueryHandler_DuplexRelay(BaseServerTransmissionController tc, UniformQueries.Query query)
{
bool decryptionComplete = false;
bool decryptionResult = false;
Task decryptionOperation = new Task(async delegate()
{
// Try to encrypt receved message.
decryptionResult = await EnctyptionOperatorsHandler.TryToDecryptAsync(
query,
EnctyptionOperatorsHandler.AsymmetricEO);
decryptionComplete = true;
});
decryptionOperation.Start();
// Whait for decription completing.
while (!decryptionComplete)
{
Thread.Sleep(5);
}
// Loging error to client.
if (!decryptionResult)
{
// Try to get answer in string format.
SendAnswerViaPP("DUPLEX RELEAY ERROR: Data corrupted." +
" Decryption not possible. Relay terminated.", query);
return;
}
// Detect routing target.
bool relayTargetFound =
UniformClient.BaseClient.routingTable.
TryGetRoutingInstruction(query, out Instruction instruction);
// If instruction not found.
if (!relayTargetFound)
{
// If reley target not found then server will mean that query requested to itself.
PipesProvider.Handlers.Queries.ProcessingAsync(tc, query);
//// Log
//Console.WriteLine("RELAY TARGET NOT FOUND: {q}", query);
//// DO BACKWARED ERROR INFORMATION.
//SendAnswer("error=404", UniformQueries.API.DetectQueryParts(query));
// Drop continue computing.
return;
}
// Open connection.
TransmissionLine tl = UniformClient.BaseClient.EnqueueDuplexQueryViaPP(
instruction.routingIP,
instruction.pipeName,
query,
// Delegate that will invoked when relayed server send answer.
// Redirects the answer to a client.
delegate(TransmissionLine answerTL, UniformQueries.Query receivedData)
{
// Try to get answer in string format.
SendAnswerViaPP(receivedData, query);
return;
});
}
/// <summary>
/// Validates and fixed a configuration and params of the transmission line.
/// </summary>
/// <param name="line">A transmission line for configuration.</param>
/// <returns>A result of configurating. False if failed.</returns>
public static async Task <bool> ConfigurateTransmissionLineAsync(TransmissionLine line)
{
if (line.RoutingInstruction != null) // Routing instruction applied.
{
// Is partial autorized instruction.
if (line.RoutingInstruction is PartialAuthorizedInstruction pai)
{
#region Token validation
// If token not exist, or emoty, or expired.
if (line.LastQuery.Data.TryGetParamValue("token", out UniformQueries.QueryPart token))
{
// If token value is emoty.
if (string.IsNullOrEmpty(token.PropertyValueString))
{
if (await TokenValidation(pai))
{
// Apply received token.
line.LastQuery.Data.SetParam(new UniformQueries.QueryPart("token", pai.GuestToken));
}
else
{
return(false);
}
}
}
else
{
// Validate token
if (await TokenValidation(pai))
{
// Add tokent to query,
line.LastQuery.Data.ListedContent?.Add(new UniformQueries.QueryPart("token", pai.GuestToken));
}
else
{
return(false);
}
}
#region Methods
// Trying to porovide valid guest token.
// Returns result of validation. False - token invalid.
async Task <bool> TokenValidation(PartialAuthorizedInstruction instruction)
{
// If guest token is not found or expired.
if (pai.GuestToken == null ||
UniformQueries.Tokens.IsExpired(instruction.GuestToken, instruction.GuestTokenHandler.ExpiryTime))
{
// Wait for token.
if (!await pai.TryToGetGuestTokenAsync(ClientAppConfigurator.TerminationTokenSource.Token))
{
return(false);
}
}
return(true);
}
#endregion
#endregion
#region Encriprion operators validation
if (line.LastQuery.Data.IsEncrypted && // Is query require encryption? (Query can't be encrypted if that query must request key for encryption.)
line.RoutingInstruction != null && // Is routing instruction is valid and allow encryption?
line.RoutingInstruction.encryption)
{
// Check asymmetric operator.
if (pai.AsymmetricEncryptionOperator == null)
{
Console.WriteLine("Encryption operator not configurated. Operation declined.");
return(false);
}
#region Receiving public key from intruction's target server
// Check if operator is valid.
if (!pai.AsymmetricEncryptionOperator.IsValid)
{
try
{
// Start async key exchanging.
var keysExchangingOperator = RequestPublicEncryptionKeyAsync(pai);
try
{
if (!keysExchangingOperator.IsCompleted)
{
keysExchangingOperator.Start();
}
}
catch { };
// Drop current query as invalid cause encryption operator still in processing.
line.Processing = false;
return(false);
}
catch (Exception ex)
{
// Unlock loop.
line.Processing = false;
Console.WriteLine("SECRET KEY ERROR (bcpph1): " + ex.Message);
return(false);
}
}
#endregion
#region Adding public key for backward encryption if not added yet
if (!line.LastQuery.Data.QueryParamExist("pk"))
{
line.LastQuery.Data.SetParam(new UniformQueries.QueryPart(
"pk",
EnctyptionOperatorsHandler.AsymmetricEO.EncryptionKey));
}
#endregion
// Encrypt query by public key of target server.
return(await EnctyptionOperatorsHandler.TryToEncryptAsync(
line.LastQuery.Data,
line.RoutingInstruction.sEncCode,
line.RoutingInstruction.AsymmetricEncryptionOperator,
ClientAppConfigurator.TerminationTokenSource.Token));
}
#endregion
}
}
return(true);
}
/// <summary>
/// A handler that will recives a message from a server.
/// </summary>
/// <param name="sharedObject">
/// Normaly is a <see cref="TransmissionLine"/> that contains information about current transmission.
/// </param>
public static async void HandlerInputTransmissionAsync(object sharedObject)
{
// Drop as invalid in case of incorrect transmitted data.
if (!(sharedObject is TransmissionLine lineProcessor))
{
Console.WriteLine("TRANSMISSION ERROR (UQPP0): INCORRECT TRANSFERD DATA TYPE. PERMITED ONLY \"LineProcessor\"");
return;
}
// Mark line as busy to avoid calling of next query, cause this handler is async.
lineProcessor.Processing = true;
#region Reciving message
// Open stream reader.
byte[] receivedData = null;
try
{
Console.WriteLine("{0}/{1}: WAITING FOR MESSAGE",
lineProcessor.ServerName, lineProcessor.ServerPipeName);
// Avoid an error caused to disconection of client.
try
{
receivedData = await UniformDataOperator.Binary.IO.StreamHandler.StreamReaderAsync(lineProcessor.pipeClient);
}
// Catch the Exception that is raised if the pipe is broken or disconnected.
catch (Exception e)
{
// Log error.
Console.WriteLine("DNS HANDLER ERROR (USAH0): {0}", e.Message);
// Stop processing merker to pass async block.
lineProcessor.Processing = false;
// Close processor case this line already deprecated on the server side as single time task.
lineProcessor.Close();
return;
}
}
// Catch the Exception that is raised if the pipe is broken or disconnected.
catch (Exception e)
{
// Log
if (receivedData == null || receivedData.Length == 0)
{
Console.WriteLine("DNS HANDLER ERROR ({1}): {0}", e.Message, lineProcessor.pipeClient.GetHashCode());
}
}
#endregion
// Log
if (receivedData == null || receivedData.Length == 0)
{
Console.WriteLine("{0}/{1}: RECEIVED MESSAGE IS EMPTY.",
lineProcessor.ServerName, lineProcessor.ServerPipeName);
}
else
{
// Log state.
Console.WriteLine("{0}/{1}: MESSAGE RECIVED",
lineProcessor.ServerName, lineProcessor.ServerPipeName);
// Decode to Query.
UniformQueries.Query receviedQuery;
try
{
receviedQuery = UniformDataOperator.Binary.BinaryHandler.FromByteArray <UniformQueries.Query>(receivedData);
}
catch (Exception ex)
{
Console.WriteLine("DNS HANDLER ERROR 401({1}): QUERY DAMAGED : {0}", ex.Message, lineProcessor.pipeClient.GetHashCode());
// Stop processing merker to pass async block.
lineProcessor.Processing = false;
// Close processor case this line already deprecated on the server side as single time task.
lineProcessor.Close();
return;
}
// Decrypt if required.
await EnctyptionOperatorsHandler.TryToDecryptAsync(
receviedQuery,
EnctyptionOperatorsHandler.AsymmetricEO,
ClientAppConfigurator.TerminationTokenSource.Token);
#region Processing message
// Try to call answer handler.
string tableGUID = lineProcessor.ServerName + "\\" + lineProcessor.ServerPipeName;
// Look for delegate in table.
if (DuplexBackwardCallbacks[tableGUID] is
Action <TransmissionLine, UniformQueries.Query> registredCallback)
{
if (registredCallback != null)
{
// Invoke delegate if found and has dubscribers.
registredCallback.Invoke(lineProcessor, receviedQuery);
// Drop reference.
DuplexBackwardCallbacks.Remove(tableGUID);
// Inform subscribers about answer receiving.
eDuplexBackwardCallbacksReceived?.Invoke(tableGUID);
}
else
{
Console.WriteLine("{0}/{1}: ANSWER CALLBACK HAS NO SUBSCRIBERS",
lineProcessor.ServerName, lineProcessor.ServerPipeName);
}
}
else
{
Console.WriteLine("{0}/{1}: ANSWER HANDLER NOT FOUND BY {2}",
lineProcessor.ServerName, lineProcessor.ServerPipeName, tableGUID);
}
//Console.WriteLine("{0}/{1}: ANSWER READING FINISH.\nMESSAGE: {2}",
// lineProcessor.ServerName, lineProcessor.ServerPipeName, message);
#endregion
}
// Stop processing merker to pass async block.
lineProcessor.Processing = false;
// Close processor case this line already deprecated on the server side as single time task.
lineProcessor.Close();
}
/// <summary>
/// Code that will work on server loop when connection will be established.
/// Recoomended to using as default DNS Handler for queries reciving.
/// </summary>
public static async void ClientToServerAsync(BaseServerTransmissionController controller)
{
DateTime sessionTime = DateTime.Now.AddSeconds(5000);
// Read until trasmition exits not finished.
while (controller.PipeServer.IsConnected)
{
// Open stream reader.
byte[] binaryQuery;
#region Reciving message
// Read data from stream.
// Avoid an error caused to disconection of client.
try
{
binaryQuery = await StreamHandler.StreamReaderAsync(controller.PipeServer);
}
// Catch the Exception that is raised if the pipe is broken or disconnected.
catch (Exception e)
{
Console.WriteLine("DNS HANDLER ERROR: {0}", e.Message);
return;
}
if (DateTime.Compare(sessionTime, DateTime.Now) < 0)
{
Console.WriteLine("Connection terminated cause allowed time has expired.");
// Avoid disconnectin error.
try
{
controller.PipeServer.Disconnect();
}
catch
{
// Exception caused by disconecction on client side.
}
return;
}
#endregion
#region Finalizing connection
// Disconnect user if query recived.
if (controller.PipeServer.IsConnected)
{
try
{
controller.PipeServer.Disconnect();
}
catch
{
// Exception caused by disconecction on client side.
}
}
// Remove temporal data.
controller.PipeServer.Dispose();
#endregion
#region Query processing
// Drop if stream is over.
if (binaryQuery == null || binaryQuery.Length == 0)
{
//Console.WriteLine("NULL REQUEST AVOIDED. CONNECTION TERMINATED.");
break;
}
// Decode query from binary data.
Query query;
try
{
query = UniformDataOperator.Binary.BinaryHandler.FromByteArray <Query>(binaryQuery);
}
catch (Exception ex)
{
Console.WriteLine("DNS HANDLER ERROR (DNS50): DAMAGED DATA : {0}", ex.Message);
return;
}
// Try to decrypt. In case of fail decryptor returns an entry message.
await EnctyptionOperatorsHandler.TryToDecryptAsync(
query, EnctyptionOperatorsHandler.AsymmetricEO);
// Log query.
Console.WriteLine(@"RECIVED QUERY (DNS0): {0}", query);
// Try to get correct transmisssion controller.
if (controller is ClientToServerTransmissionController CToSTS)
{
// Redirect handler.
CToSTS.queryHandlerCallback?.Invoke(controller, query);
}
else
{
// Log error.
Console.WriteLine(@"DNS HANDLER ERROR (DNS40):\nQuery processing not posssible.\nTransmission controller not {0}",
typeof(ClientToServerTransmissionController).FullName);
}
#endregion
}
// Log about transmission finish.
Console.WriteLine("{0} : TRANSMISSION FINISHED AT {1}",
controller.PipeName, DateTime.Now.ToString("HH:mm:ss.fff"));
}
