/*

* Copyright (c) 2007-2008 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:    Implements functionality of NATFW STUN server client session

*

*/

#ifndef NATFWSTUNSRVIMPL_H

#define NATFWSTUNSRVIMPL_H

#include <e32base.h>

#include <in_sock.h>

#include "natfwconnectivityapidefs.h"

#include "mncmincomingconnectionobserver.h"

#include "natfwunsaftransactionid.h"

class MNATFWStunSrvObserver;

class CNATFWCredentials;

class CNATFWUNSAFMessage;

class MNcmConnectionMultiplexer;

/**

 * Implementation class of NATFW STUN server.

 *

 * @lib stunserver.lib

 * @since S60 v3.2

 */                                                   

NONSHARABLE_CLASS( CNATFWSTUNSrvImpl ) : public CBase, 

    public MNcmIncomingConnectionObserver

    {

    friend class ut_cnatfwstunsrvimpl;

public:

    /**

     * Two-phased constructor.

     * @param aObserver    A callback object to receive and handle

     *                     event notifications from NAT FW STUN server.

     * @param aObserver    Stun server observer

     * @param aMultiplexer A multiplexer

     */

    static CNATFWSTUNSrvImpl* NewL( MNATFWStunSrvObserver& aObserver,

        MNcmConnectionMultiplexer& aMultiplexer );

    /**

     * Destructor.

     */

    virtual ~CNATFWSTUNSrvImpl();

    /**

     * Adds authentication params which are used to authenticate

     * incoming binding requests.

     * 

     * Notifies the client of STUN requests that are valid.

     *  

     * @since S60 3.2

     * @param aIdentifications Identification array.

     * @return void

     */

    void AddAuthenticationParamsL( 

        const RPointerArray<CNATFWCredentials>& aIdentifications );

    /**

     * Removes specified authentication params from STUN server.

     *  

     * @since S60 3.2

     * @param aIdentifications Identification array.

     * @return void

     */

    void RemoveAuthenticationParamsL( 

        const RPointerArray<CNATFWCredentials>& aIdentifications );

    /**

     * Sets role for an agent. 

     *  

     * @since S60 3.2

     * @param aRole       Either controlling or controlled.  

     * @param aTieBreaker Value for determining which agent will change

     *                    Role if role conflict is present

     * @return void

     */             

    void SetRoleL( TNATFWIceRole aRole, TUint64 aTieBreaker );

// from base class MNcmIncomingConnectionObserver

    void IncomingMessageL( TUint aStreamId, 

        const TDesC8& aMessage, const TInetAddr& aLocalAddr, 

        const TInetAddr& aFromAddr, const TInetAddr& aPeerRemoteAddress,

        TBool& aConsumed );

private: // Constructors

    void ConstructL( MNcmConnectionMultiplexer& aMultiplexer );

    CNATFWSTUNSrvImpl( MNATFWStunSrvObserver& aObserver );

private: // private methods

    /**

     * Function that checks if role conflict is present between agents.

     *

     * @since S60 3.2   

     * @param aRequest UNSAF message.    

     * return ETrue if chosen role conflicts

     *        EFalse if not 

     */    

    TBool IsRoleConflictPresent( const CNATFWUNSAFMessage& aRequest );

    /**

     * Setting function for changing peer remote address.

     * @since S60 3.2

     * @param aFromAddr          Address the server saw in request.

     * @param aPeerRemoteAddress Peer remote address.

     * return void

     */

    void SetPeerRemoteAddress( const TInetAddr& aFromAddr,

        TInetAddr& aPeerRemoteAddress) const;

    /**

     * Decodes a byte stream and return the decoded UNSAF message.

     *  

     * @since S60 3.2

     * @param aData Incoming message data.

     * @return Decoded message, ownership is transferred.

     *         NULL if the stream didn't contain an UNSAF message.

     * @return One of the standard system-wide error codes.

     */    

    CNATFWUNSAFMessage* DecodeMessageL( const TDesC8& aData ) const;

    /**

     * Encodes an UNSAF message.

     *

     * @since S60 3.2

     * @param aRequest   UNSAF message.

     * @param aPassword  Key for checking the message integrity.

     * @param aErrorCode Error code.

     * @return

     */

    HBufC8* EncodeMessageL( const CNATFWUNSAFMessage& aRequest, 

        const TDesC8& aPassword, const TInt aErrorCode ) const;

    /**

     * Validates the request. Authenticate and check message integrity.

     * Sends binding response if everything goes right and error response

     * if there is missing argument or message integrity check fails.

     *  

     * @since S60 3.2

     * @param aRequest    UNSAF message.

     * @param aByteStream Same UNSAF message as aRequest, but in undecoded

     *                    format.

     * @return ETrue if needed attributes are present in binding request.

     *         EFalse if any needed attribute is missing.

     */

    TBool IsRequestValidL( const CNATFWUNSAFMessage& aRequest,

                           const TDesC8& aByteStream );

    /**

     * Verifies the integrity of a Binding Request.

     *  

     * @since S60 3.2

     * @param aRequest    UNSAF message.

     * @param aByteStream Same message as aRequest, but in undecoded format

     * @param aPassword   Key for checking the message integrity.

     * @return ETrue If integrity check succeeded.

     *         EFalse Integrity check fails.

     */    

    TBool CheckIntegrityL( const CNATFWUNSAFMessage& aRequest,

                           const TDesC8& aByteStream,

                           const TDesC8& aPassword );

    /**

     * Finds the credential which match for the given username and

     * returns the password.

     *  

     * @since S60 3.2

     * @param aRequest The received UNSAF message.

     * @param aError Returns error code via reference 

     * @return Password NUll if password not found.

     */                                     

    HBufC8* GetPassword( const CNATFWUNSAFMessage& aRequest, TInt& aError );

    /**

     * Creates and sends binding response or binding error response.

     *  

     * @since S60 3.2

     * @param aRequest   The received UNSAF message.

     * @param aErrorCode Error code.

     * @param aPassword  Password is used to calculate message integrity.

     * @return void

     */

    void SendResponseL( const CNATFWUNSAFMessage& aRequest, TInt aErrorCode, 

                        const TDesC8& aPassword );

    TBool IsRetransmittedRequest( const CNATFWUNSAFMessage& aRequest ) const;

    void SaveTransactionIdL( const TNATFWUNSAFTransactionID& aId );

    TInt FindTransactionId( const TNATFWUNSAFTransactionID& aId ) const;

private:

    /*

     * Observer for STUN request related notifies.

     */

    MNATFWStunSrvObserver& iObserver;

    /**

     * Identification array, password for authentication

     */

    RPointerArray<CNATFWCredentials> iIdentificationArray;

    /**

     * A Stream Id

     */

    TUint iStreamId; 

    /**

     * Remote address

     */

    TInetAddr iFromAddress;

    /**

     * Multiplexer instance

     * Not own.

     */

    MNcmConnectionMultiplexer* iMultiplexer;

    /**

     * Peer remote address

     */

    TInetAddr iPeerAddr;

    /**

     * Local address

     */

    TInetAddr iLocalAddress;

    /**

     * Username

     * Own.

     */

    HBufC8* iUsername;

    /**

     * Boolean indicating if data indication includes STUN binding request

     */

    TBool iRequestInsideIndication;

    /**

     * Current role

     */

    TInt iRole;

    /**

     * Chosen role conflicts with another agent if true

     */

    TBool iRoleConflict;

    /**

     * Value for determining which agent will change it's role if role 

     * conflict is present

     */

    TUint64 iTieBreaker;

    /**

     * Array containing latest transaction identifiers.

     */

    RArray<TNATFWUNSAFTransactionID> iTransactionIds;

    };

#endif // NATFWSTUNSRVIMPL_H