//dnsproxyengine.h

/*

* Copyright (c) 2008-2009 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:

* dnsproxyengine.h - Dns Engine class

* @file

* @internalTechnology

*

*/

#ifndef DNS_PROXY_ENGINE_H

#define DNS_PROXY_ENGINE_H

#include <es_ini.h>

#include <es_enum.h> 

#include "dnsproxyserver.h"

#include "dnsproxydb.h"

#include "dns_hdr.h"

//Literals constants for reading .ini file

_LIT(DNS_PROXY_INI_DATA,             "resolver.ini");

_LIT(DNS_PROXY_INI_SECTION,          "proxyresolver");	

_LIT(DNS_PROXY_INI_NUM_SOCK_SESSION, "sessioncount");

_LIT(DNS_PROXY_INI_NUM_RETRIES,      "retries");	

_LIT(DNS_PROXY_INI_QUEUE_SIZE,       "queuesize");

_LIT(DNS_PROXY_INI_TTL,              "TTL");

_LIT(DNS_PROXY_INI_DB_SIZE,          "dbsize");

_LIT(DNS_PROXY_INI_TIMER_VAL,        "timerval");

_LIT(DNS_PROXY_INI_SERIAL_NUM,       "serialnum");

_LIT(DNS_PROXY_INI_REFRESH_TIME,     "refreshtime");

_LIT(DNS_PROXY_INI_RETRY_TIME,       "retrytime");

_LIT(DNS_PROXY_INI_EXPIRE_TIME,      "expiretime");

const TUint   KSessioncount = 1;

const TUint   KRetrycount   = 2;

const TUint   KQSize 		= 20;

const TUint   KTtl		    = 21600;//dhcp lease timer is 6 hrs

const TUint   KDbSize       = 10;

const TUint   KTimerVal     = 5;

const TUint32 KSerialNum   = 10000;

const TUint32 KRefreshTime = 900;

const TUint32 KRetryTime   = 600;

const TUint32 KExpireTime  = 300;

const TUint32 KAddrLength  = 100;

//T Type class for DNS Proxy Configuration parameters

class TDnsProxyConfigParams

	{

public:

    TUint iSessionCount;//< Max number of Socket sessions  

    TUint iRetryCount;	//< Possible number of retries 

    TUint iQSize;       //< Queue size limit 

    TUint iTTL;			//< Time to Live

    TUint iDbSize;      //< Max number of DB entries

	TUint iTimerVal;	//< Timeout value for response timer

	TUint32 iSerialNum; //< This is required for NS response

	TUint32 iRefreshTime; //< This is required for NS response

	TUint32 iRetryTime; //< This is required for NS response

	TUint32 iExpiretime; //< This is required for NS response

	};

//forward declaration

class CDnsProxyListener;

class CESockIniData;

class CDnsProxyDb;

class CDnsServerConfig;

/**

 *  This class is an entry point and reads all configuration values and creates 

 *  some necessary objects

 *  @internalTechnology

 * */

class CDnsProxyEngine:public CBase

	{

	public:

		//two phase construction

        static CDnsProxyEngine* GetInstanceL();

		~CDnsProxyEngine();

		//Starts DNSProxy. The method is called from DNSProxy server session.

		TInt Start(const RMessage2& aMessage);

		//Stops DNSProxy. The method is called from DNSProxy server session.

		void Stop();

		//Returns instance of socket server

		RSocketServ& GetSocketServer();

		//Returns an instance of Listener

		CDnsProxyListener* GetProxyListener();

	    // The method updates DNS Proxy DB. 

		TInt AddDbEntryL(const RMessage2& aMsg);

		//remove entry from db

		TInt RemoveDbEntry(const RMessage2& aMsg);

		//This method updates domain name

		void UpdateDomainName(const RMessage2& aMsg);

		// The method to update domain info

		TInt UpdateDomainInfo(const RMessage2& aMsg);

		void UpdateLocalAddr(TInetAddr& aAddr);

		// Suffix is available or not

		TInt IsSuffixAvailable();

	    //This method returns the configuration parameters read from .ini file.

		const TDnsProxyConfigParams& GetConfig() const;

		TInt SetDlinkConnectionInfo(const RMessage2 &aMessage);

		TInt SetUplinkConnectionInfo(const RMessage2 &aMessage);

	protected:

	    // Initializes the member variables

		void ConstructL();	

	private:

        static CDnsProxyEngine* NewL();

		//constructor

		CDnsProxyEngine();

		//reads the configuation file

		void ReadConfiguration();

		//reads the configuation file for specified name /value pair	

		TInt GetIniValue(const TDesC& aSection, const TDesC& aName, TInt aValue=0);

		//finds the value for given name 

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

		//loads the cinfiguaration file 

		TBool LoadConfigurationFile();

		//unloads cinfiguration file

		void UnLoadConfigurationFile();

	public:

		TDnsProxyConfigParams 	    iConfigParams;		//< Parsed configuration parameters

		CDnsServerConfig* 		    iProxyServer;		//< DNS server configuration

		CDnsProxyDb* 				iDnsproxydb;          //< DNS Proxy db instance

		TInetAddr                   iProxyIfAddr;		//< Listener interface address

		TBuf8<KMaxName>             iSuffixInfo;

	private:

		CESockIniData* 			    iConfigData;		//< Used to read config data 		

		TInt 					    iConfigDataErr;     //< Contains config data error

		RSocketServ 			    iSockServ;          //< socket server handler

		CDnsProxyListener* 		    iListener;          //< Intance of listener object

		TBool                       iSuffixAvailable;   //< Suffix is available

	private:

		TBuf<KDnsMaxMessage> iBuf;	      //< Receive buffer

		TBuf<KDnsMaxMessage> iDomainName; 

		static CDnsProxyEngine* iDnsProxyEngine;

	};

 inline const TDnsProxyConfigParams& CDnsProxyEngine::GetConfig() const

 /**

 *  This method returns an instance of config params 

 *  @internalTechnology

 * */ 

 	{ 

 	return iConfigParams; 

 	}

 inline RSocketServ& CDnsProxyEngine::GetSocketServer()

/**

 *  This method returns an instance of socket server 

 *  @internalTechnology

 * */

	{

	return iSockServ;

	}

inline CDnsProxyListener* CDnsProxyEngine::GetProxyListener()

/**

 *  This method returns an instance of listener object

 *  @internalTechnology

 * */

	{

	return iListener;

	}

#endif /* DNS_PROXY_ENGINE_H */