// Copyright (c) 2004-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

// engine.h - name resolver core engine header

//

#ifndef __ENGINE_H

#define __ENGINE_H

#include <s32file.h>

#include <es_sock.h>

#include <in_sock.h>

/**

@file engine.h

Engine component

@internalComponent	Domain Name Resolver

*/

#include "demon.h"

#include "hosts.h"

const TUint KQueryOrder_PreferA = 0x1;	//< if set, send A first, and then AAAA (preferred query) 

const TUint KQueryOrder_Parallel = 0x2;	//< if set, activate both queries without waiting the first to complete.

const TUint KQueryOrder_OneQuery = 0x4;	//< if set, send only the preferred query (either A or AAAA)

/**

// Configuration parameter which are extracted from the [resolver] sections

*/

class TDndConfigParameters

	{

public:

	TUint iRetries;			//< # of query retransmissions (not counting the first)

	TUint iMinTime;			//< Minimum time for retransmit

	TUint iMaxTime;			//< Maximum time for the total query to complete or fail (when server is known)

	TUint iSetupTime;		//< Maximum time to wait for DNS server to become known

	TUint iSetupPoll;		//< While waiting DNS server, interval for rechecking status (even if no monitor events)

	TUint iSprayMode:1;		//< Each query is sent to all servers with iMinTime interval (on each try)

	TUint iSkipNotFound:1;	//< Ignore "Name not found" answers from server and try another server.

	TUint iQueryHack:1;		//< Enable "QUERYTYPE?Name" special queries

	TUint iQueryOrder:3;	//< Define how A and AAAA queries are to be used.

	TUint iFlushOnConfig:1;	//< Flush DNS cache on intereface configuration change.

#ifdef LLMNR_ENABLED

    TUint iLlmnrLlOnly:1;   //< Accept only link-local replies to LLMNR queries

    TUint iLlmnrPort;       //< Default port of the Linklocal Multicast Name Resolver

	TUint iLlmnrRetries;	//< # of LLMNR query retransmissions (not counting the first)

	TUint iLlmnrMinTime;	//< Minimum time to retransmit the LLMNR query

	TUint iLlmnrMaxTime;	//< Maximum time to do LLMNR query

	TInt  iLlmnrHoplimit;	//< The IP Hoplimit (TTL) to be used in LLMR/MDNS packets.

	TIp6Addr iLlmnrIpv4;	//< The IPv4 multicast address

	TIp6Addr iLlmnrIpv6;	//< The IPv6 multicast address

#endif

	TUint iEDNS0;			//< Enable EDNS0, if >= KDnsMaxMessage, value is receive payload size.

	};

class MTimeoutManager;

class MDndListener;

class CESockIniData;

/**

// Engine part of the DND implementation.

// 

// Function

//

// @li	The engine (there will be only one instantiation) acts as the controller.

// @li	Creates and owns the CdndListener.

// @li	Maintains the communication between the other componens and the console.

//

// Contains

//

// @li	CDndListener object -  to accept socket connection from the applications requiring service

// @li	A view - to show error and log messages

// @li	A File Server handle

// @li	A Socket Server handle

// @li	A timeout manager instance for other components to use

*/

class CDndEngine : public CBase, public MDemonEngine

	{

public:

	CDndEngine(MDemonMain &aMain) : iMain(aMain), iHostsFile(iFS) {}

	~CDndEngine();

	void ConstructL();

	void HandleCommandL(TInt aCommand);

	MDemonMain &iMain;			//< The reference to the main application

public:

	RFs iFS;					//< A File Server session (opened/closed by engine)

	RSocketServ iSS;			//< A Socket Server session (opened/opened by engine)

	RHostsFile iHostsFile;		//< The hosts file source

	RSocket iSocket;			//< And Open UDP socket,for all to use for SetOpt/GetOpt only.

	// @brief If aResult < 0 (= error), output message and leave

	void CheckResultL(const TDesC &aText, TInt aResult);

	// @brief If aResult < 0 (= error), output messsage

	TInt CheckResult(const TDesC &aText, TInt aResult);

	// @brief Output text message (line)

	void ShowText(const TDesC &aText);

	//	@brief Oupput text message using format (line)

	void ShowTextf(TRefByValue<const TDesC> aFmt, ...);

	//

	// Access to the configuration file

	//

	// @brief	Find integer value from configuration with automatic min/max and default checking.

	TInt GetIniValue(const TDesC &aSection, const TDesC &aName, TInt aDefault = 0, TInt aMin = 0, TInt aMax = 1);

	// @brief	Find IP address value from configuration.

	void GetIniAddress(const TDesC &aSection, const TDesC &aName, const TDesC &aDefault, TIp6Addr &aAddr);

	// @brief	Find string value from configuration

	TBool FindVar(const TDesC &aSection, const TDesC &aVarName,TPtrC &aResult);

	// @brief	Find integer value from configuration

	TBool FindVar(const TDesC &aSection, const TDesC &aVarName,TInt &aResult);

	// @brief Release Configuration data

	void UnloadConfigurationFile();

	// @return parsed configuration parameters

	inline const TDndConfigParameters &GetConfig() const { return iParams; }

	// @return handle for the Timeout manager

	MTimeoutManager &Timer() { return *iTimer; }

private:

	// @brief Called implicitly by FindVar methods

	TBool LoadConfigurationFile();

	CESockIniData *iConfig;				//< Configuration data

	TInt iConfigErr;					//< Non-zero, if configuration file is not available

	TDndConfigParameters iParams;		//< Parsed configuration parameters

	MTimeoutManager *iTimer;			//< Generic timer handler (made available for all components)

	MDndListener *iListener;			//< The listener instance

	};

#endif