// 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 the License "Symbian Foundation License v1.0" to Symbian Foundation members and "Symbian Foundation End User License Agreement v1.0" to non-members

 // which accompanies this distribution, and is available

 // at the URL "http://www.symbianfoundation.org/legal/licencesv10.html".

 //

 // Initial Contributors:

 // Nokia Corporation - initial contribution.

 //

 // Contributors:

 //

 // Description:

 // ext_hdr.h - IPv6 extension headers

 // Defines the basic classes for accessing the extension

 // header structures within IPv6 packets.

 // All return types codified as TInt (Native form and signed)

 //

 /**

  @file ext_hdr.h

  @ingroup ip_packet_formats

  @publishedAll

  @released

 */

 #ifndef __EXT_HDR_H__

 #define __EXT_HDR_H__

 #include <e32def.h>

 #include "in_hdr.h"

 /**

 * @addtogroup  ip_packet_formats

 * @{

 */

 /**

 * @name Additional protocol numbers

 *

 * @{

 */

 /** Hop-by-Hop Extension Header. See TInet6HeaderHopByHop. */

 const TUint KProtocolInet6HopOptions = 0;

 /** Tunneled IPv4. The next header is TInet6HeaderIP4. */

 const TUint KProtocolInetIpip = 4;

 /** Routing Header. See TInet6HeaderRouting. */

 const TUint KProtocolInet6RoutingHeader = 43;

 /** IPv6 Fragment Header. See TInet6HeaderFragment. */

 const TUint KProtocolInet6Fragment = 44;

 /** IPsec ESP header. See TInet6HeaderESP. */

 const TUint KProtocolInetEsp	= 50;

 /** IPsec AH header. See TInet6HeaderAH. */

 const TUint KProtocolInetAh = 51;

 /** No Next Header. */

 const TUint KProtocolInet6NoNextHeader = 59;

 /** Destination Options Extension Header. See TInet6Options. */

 const TUint KProtocolInet6DestinationOptions = 60;

 /* @} */

 //

 // TInet6HeaderExtension

 // *********************

 class TInet6HeaderExtension

 	/**

 	* Basic part of normal IPv6 extension headers.

 	*

 	* This is simple class to be used in scanning the extension headers

 	* which are known to follow the following format:

 	*

 	* - 1st octet = Next Header field

 	*

 	* - 2nd octet = Length of the extension header (= (x+1)*8 octets)

 	*

 	* @note

 	*	Extension headers do not need to follow this format. Unknown

 	*	headers cannot be skipped over by just assuming this format!

 	*

 	* @publishedAll

 	* @released

 	*/

 	{

 public:

 	inline static TInt MinHeaderLength() {return 8; }

 	inline static TInt MaxHeaderLength() {return 8; }	

 	inline TUint8* EndPtr() { return i + HeaderLength(); }

 	inline TInt NextHeader() const { return i[0]; }

 	inline TInt HdrExtLen() const { return i[1]; }	// Return raw value

 	inline TInt HeaderLength() const { return (i[1]+1) << 3; } // Return true byte length

 private:

 	union

 		{

 		TUint8 i[8];

 		TUint32 iAlign;	// A dummy member to force the 4 byte alignment

 		};

 	};

 class TInet6HeaderHBH

 	/**

 	* IPv6 Hop-by-hop options header.

 @verbatim

 	From RFC 2460

     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

     |  Next Header  |  Hdr Ext Len  |                               |

     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               +

     |                                                               |

     .                                                               .

     .                            Options                            .

     .                                                               .

     |                                                               |

     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

    Next Header          8-bit selector.  Identifies the type of header

                         immediately following the Hop-by-Hop Options

                         header.  Uses the same values as the IPv4

                         Protocol field [RFC-1700 et seq.].

    Hdr Ext Len          8-bit unsigned integer.  Length of the Hop-by-

                         Hop Options header in 8-octet units, not

                         including the first 8 octets.

    Options              Variable-length field, of length such that the

                         complete Hop-by-Hop Options header is an integer

                         multiple of 8 octets long.  Contains one or more

                         TLV-encoded options, as described in section

                         4.2.

   And Options is:

 	  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - -

       |  Option Type  |  Opt Data Len |  Option Data

       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - -

       Option Type          8-bit identifier of the type of option.

       Opt Data Len         8-bit unsigned integer.  Length of the Option

                            Data field of this option, in octets.

       Option Data          Variable-length field.  Option-Type-specific

                            data.

 @endverbatim

 	* @publishedAll

 	* @released

 	*/

 	{

 public:

 	inline TInt HeaderLength() const

 		{

 		return (i[1]+1) << 3;	// Return length in octets.

 		}

 	inline TUint8* EndPtr() { return i + HeaderLength(); }

 	inline static TInt MinHeaderLength() {return 8; }	

 	inline static TInt MaxHeaderLength() {return 8; }

 	//

 	// Access, Get Hop By Hop header values from the packet

 	//

 	inline TInt NextHeader() const

 		{

 		return i[0];

 		}

 	//From Options

 	inline TInt OptionType() const

 		/** @return The type of the first option */

 		{

 		return i[2];

 		}

 	inline TInt OptionDataLen() const

 		/** @return The data length of the first option */

 		{

 		return i[3];

 		}

 	//

 	// Access, SET Hop By Hop header values

 	//

 	inline void SetHdrExtLen(TInt aLength)

 		{

 		i[1]=(TUint8)aLength;

 		}

 	inline void SetNextHeader(TInt aNext)

 		{

 		i[0]=(TUint8)aNext;

 		}

 	//From Options

 	inline void SetOptionType(TInt aType)

 		/** Sets type of the first option.*/

 		{

 		i[2]=(TUint8)aType;

 		}

 	inline void SetOptionDataLen(TInt aLength)

 		/** Sets data length of the first option.*/

 		{

 		i[3]=(TUint8)aLength;

 		}

 private:

 	union

 		{

 		TUint8 i[8];

 		TUint32 iAlign;	// A dummy member to force the 4 byte alignment

 		};

 	};

 class TInet6HeaderHopByHop

 	/**

 	* IPv6 Hop-by-hop options header.

 	* @publishedAll

 	* @deprecated

 	*	Because of the non-standard method naming and

 	*	semantics. Use TInet6HeaderHBH instead.

 	*/

 	{

 public:

 	inline TInt HeaderLength() const

 		{

 		return i[1];

 		}

 	inline TUint8* EndPtr() { return i + HeaderLength() * 8 + MinHeaderLength(); }

 	inline static TInt MinHeaderLength() {return 8; }	

 	inline static TInt MaxHeaderLength() {return 8; }

 	//

 	// Access, Get Hop By Hop header values from the packet

 	//

 	inline TInt NextHeader() const

 		/** @return The length in 8-byte units! (non-standard, should be bytes!) */

 		{

 		return i[0];

 		}

 	//From Options

 	inline TInt OptionType() const

 		/** @return The type of the first option */

 		{

 		return i[2];

 		}

 	inline TInt OptionDataLen() const

 		/** @return The data length of the first option */

 		{

 		return i[3];

 		}

 	//

 	// Access, SET Hop By Hop header values

 	//

 	inline void SetHeaderLength(TInt aLength)

 		{

 		i[1]=(TUint8)aLength;

 		}

 	inline void SetNextHeader(TInt aNext)

 		{

 		i[0]=(TUint8)aNext;

 		}

 	//From Options

 	inline void SetOptionType(TInt aType)

 		/** Sets type of the first option.*/

 		{

 		i[2]=(TUint8)aType;

 		}

 	inline void SetOptionDataLen(TInt aLength)

 		/** Sets data length of the first option.*/

 		{

 		i[3]=(TUint8)aLength;

 		}

 private:

 	union

 		{

 		TUint8 i[8];

 		TUint32 iAlign;	// A dummy member to force the 4 byte alignment

 		};

 	};

 class TInet6HeaderRouting

 	/**

 	* IPv6 Routing Header.

 	* The Type 0 Routing header has the following format:

 @verbatim

     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

     |  Next Header  |  Hdr Ext Len  | Routing Type=0| Segments Left |

     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

     |                            Reserved                           |

     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

     |                                                               |

     +                                                               +

     |                                                               |

     +                           Address[1]                          +

     |                                                               |

     +                                                               +

     |                                                               |

     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

     |                                                               |

     +                                                               +

     |                                                               |

     +                           Address[2]                          +

     |                                                               |

     +                                                               +

     |                                                               |

     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

     .                               .                               .

     .                               .                               .

     .                               .                               .

     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

     |                                                               |

     +                                                               +

     |                                                               |

     +                           Address[n]                          +

     |                                                               |

     +                                                               +

     |                                                               |

     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

    Next Header          8-bit selector.  Identifies the type of header

                         immediately following the Routing header.  Uses

                         the same values as the IPv4 Protocol field

                         [RFC-1700 et seq.].

    Hdr Ext Len          8-bit unsigned integer.  Length of the Routing

                         header in 8-octet units, not including the first

                         8 octets.  For the Type 0 Routing header, Hdr

                         Ext Len is equal to two times the number of

                         addresses in the header.

    Routing Type         0.

    Segments Left        8-bit unsigned integer.  Number of route

                         segments remaining, i.e., number of explicitly

                         listed intermediate nodes still to be visited

                         before reaching the final destination.

    Reserved             32-bit reserved field.  Initialized to zero for

                         transmission; ignored on reception.

    Address[1..n]        Vector of 128-bit addresses, numbered 1 to n.

 @endverbatim

 	* This header mapping describes only the fixed part, without

 	* any addresses.

 	* @publishedAll

 	* @released

 	*/

 	{

 public:

 	inline static TInt MinHeaderLength() {return 8; }

 	inline static TInt MaxHeaderLength() {return 8; }	

 	inline TUint8* EndPtr() { return i + HeaderLength(); }

 	enum TOffsets

 		{

 		O_NextHeader,

 		O_HdrExtLen,

 		O_RoutingType,

 		O_SegmentsLeft,

 		O_Address = 8

 		};

 	inline TInt NextHeader() const { return i[0]; }

 	inline TInt HdrExtLen() const { return i[1]; }	// Return raw value

 	inline TInt HeaderLength() const { return (i[1]+1) << 3; } // Return true byte length

 	inline TInt RoutingType() const { return i[2]; }

 	inline TInt SegmentsLeft() const { return i[3]; }

 	//SET

 	inline void SetNextHeader(TInt aNext) { i[0] = (TInt8)aNext; }

 	inline void SetHdrExtLen(TInt aLen) { i[1] = (TUint8)aLen; }	

 	inline void SetRoutingType(TInt aType) { i[2] = (TUint8)aType; }

 	inline void SetSegmentsLeft(TInt aValue) { i[3] = (TUint8)aValue; }

 private:

 	union

 		{

 		TUint8 i[8];

 		TUint32 iAlign;	// A dummy member to force the 4 byte alignment

 		};

 	};

 class TInet6Options

 	/**

 	* IPv6 Option extension headers (Hop-by-Hop, Destination Options).

 	*

 @verbatim

    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

    |  Next Header  |  Hdr Ext Len  |                               |

    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               +

    |                                                               |

    .                                                               .

    .                            Options                            .

    .                                                               .

    |                                                               |

    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Next Header          8-bit selector.  Identifies the type of header

                        immediately following the Destination Options

                        header.  Uses the same values as the IPv4

                        Protocol field [RFC-1700 et seq.].

   Hdr Ext Len          8-bit unsigned integer.  Length of the

                        Destination Options header in 8-octet units, not

                        including the first 8 octets.

   Options              Variable-length field, of length such that the

                        complete Destination Options header is an

                        integer multiple of 8 octets long.  Contains one

                        or  more TLV-encoded options, as described in

                        section 4.2.

 @endverbatim

 	* This mapping describes only the minimal 8 bytes.

 	* @publishedAll

 	* @released

 	*/

 	{

 public:

 	inline TInt HeaderLength() const { return (i[1]+1) << 3; } // Return true byte length

 	inline static TInt MinHeaderLength() {return 8; }

 	inline static TInt MaxHeaderLength() {return 8; }	

 	inline TUint8* EndPtr() { return i + HeaderLength(); }

 	enum TOffsets

 		{

 		O_NextHeader,

 		O_HdrExtLen,

 		O_Options

 		};

 	inline TInt NextHeader() const { return i[0]; }

 	inline TInt HdrExtLen() const { return i[1]; }	// Return raw value

 	inline void SetNextHeader(TInt aNext) { i[0] = (TInt8)aNext; }

 	inline void SetHdrExtLen(TInt aLen) { i[1] = (TUint8)aLen; }

 private:

 	TUint8 i[8];

 	};

 /**

 * @name Destination option types.

 *

 * @{

 */

 /** One octet padding. */

 const TUint8 KDstOptionPad1				= 0;

 /** N octets padding */

 const TUint8 KDstOptionPadN				= 1;

 /** not used? (MIP6) */

 const TUint8 KDstOptionBindingAck		= 7;

 /** not used? (MIP6) */

 const TUint8 KDstOptionBindingRequest	= 8;

 /** not used? (MIP6) */

 const TUint8 KDstOptionBindingUpdate	= 0xC6;

 /** Home Address option (MIP6) */

 const TUint8 KDstOptionHomeAddress		= 0xC9;

 /** @} */

 class TInet6OptionBase

 	/**

 	* IPv6 Option value header.

 	*

 	* A basic class for handling Type-Length-Value (TLV) options.

 	*

 @verbatim

 	  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - -

       |  Option Type  |  Opt Data Len |  Option Data

       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- - - - - - - - -

       Option Type          8-bit identifier of the type of option.

       Opt Data Len         8-bit unsigned integer.  Length of the Option

                            Data field of this option, in octets.

       Option Data          Variable-length field.  Option-Type-specific

                            data.

 @endverbatim

 	* Option values are used inside option headers (for example:

 	* Hop-by-Hop options and Destination options).

 	*

 	* @publishedAll

 	* @released

 	*/

 	{

 public:

 	inline static TInt MinHeaderLength()	{ return 2; }

 	inline static TInt MaxHeaderLength()	{ return 2; }

 	inline TInt Type() const				{ return i[0]; }

 	inline TInt HeaderLength() const { return i[1] + 2; }

 	inline void SetType(TInt aType)			{ i[0] = (TUint8)aType; }

 	inline void SetDataLen(TInt aLen)		{ i[1] = (TUint8)aLen; }

 	inline TUint8* EndPtr() { return i + HeaderLength(); }

 private:

 	TUint8	i[2];

 	};

 class TInet6DstOptionBase

 	/**

 	* IPv6 Option value header.

 	* @publishedAll

 	* @deprecated

 	*	Because of the non-standard method naming and

 	*	semantics. Use TInet6OptionBase instead.

 	*/

 	{

 public:

 	inline static TInt MinHeaderLength()	{ return 2; }

 	inline static TInt MaxHeaderLength()	{ return 2; }

 	inline TInt Type() const				{ return i[0]; }

 	inline TInt HeaderLength() const { return i[1]; }

 	inline void SetType(TInt aType)			{ i[0] = (TUint8)aType; }

 	inline void SetHeaderLength(TInt aLen)	{ i[1] = (TUint8)aLen; }

 	inline TUint8* EndPtr() { return i + 2 + HeaderLength(); }

 private:

 	TUint8	i[2];

 	};

 class TInet6HeaderFragment

 	/**

 	* IPv6 Fragment Header.

 @verbatim

 RFC2460

    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

    |  Next Header  |   Reserved    |      Fragment Offset    |Res|M|

    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

    |                         Identification                        |

    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

    Next Header          8-bit selector.  Identifies the initial header

                         type of the Fragmentable Part of the original

                         packet (defined below).  Uses the same values as

                         the IPv4 Protocol field [RFC-1700 et seq.].

    Reserved             8-bit reserved field.  Initialized to zero for

                         transmission; ignored on reception.

    Fragment Offset      13-bit unsigned integer.  The offset, in 8-octet

                         units, of the data following this header,

                         relative to the start of the Fragmentable Part

                         of the original packet.

    Res                  2-bit reserved field.  Initialized to zero for

                         transmission; ignored on reception.

    M flag               1 = more fragments; 0 = last fragment.

    Identification       32 bits.  See description below.

 @endverbatim

 	* @publishedAll

 	* @released

 	*/

 	{

 public:

 	enum TOffsets

 		{

 		O_FragmentOffset = 2

 		};

 	inline TInt HeaderLength() const

 		{

 		return 8;

 		}

 	inline TUint8* EndPtr() { return i + HeaderLength(); }

 	inline static TInt MinHeaderLength() {return 8; }

 	inline static TInt MaxHeaderLength() {return 8; }

 	//

 	// Access, Get Fragmentation header values from the packet

 	//

 	inline TInt NextHeader() const { return i[0]; }

 	inline TInt FragmentOffset() const

 		{

 		//

 		//	The Offset is returned as octet count (3 righmost bits are zero)

 		//

 		return ((i[2] << 8) + i[3]) & 0xfff8;

 		}

 	inline TInt MFlag() const

 		{

 		return i[3] & 0x01;

 		}

 	inline TInt32 Id() const

 		{

 		return *(TInt32 *)(&i[4]);	// *ASSUMES* proper aligment!!!

 		}

 	//

 	// Building methods

 	//

 	inline void ZeroAll()

 		{

 		*((TInt32 *)&i[0]) = 0;		// *ASSUMES* proper aligment!!!

 		*((TInt32 *)&i[4]) = 0;		// *ASSUMES* proper aligment!!!

 		}

 	inline void SetNextHeader(TInt aNext)

 		{

 		i[0] = (TUint8)aNext;

 		}

 	inline void SetFragmentOffset(TInt aOffset)

 		{

 		//

 		// The aOffset is assumed to be given in octets. The least significant

 		// 3 bits should be ZERO (bits are just masked away).

 		//

 		i[2]=(TUint8)(aOffset >> 8);

 		i[3]=(TUint8)((i[3] & 0x7) | (aOffset & ~0x7));

 		}

 	inline void SetMFlag(TInt aFlag)

 		{

 		i[3]= (TUint8)((i[3] & ~0x1) | (aFlag & 0x1));

 		}

 	inline void SetId(TInt32 aId)

 		{

 		*((TInt32 *)&i[4]) = aId;	// *ASSUMES* proper aligment!!!

 		}

 private:

 	union

 		{

 		TUint8 i[8];

 		TUint32 iAlign;	// A dummy member to force the 4 byte alignment

 		};

 	};

 class TInet6HeaderAH

 	/**

 	* IPsec Authentication Header.

 	*

 	* The function parameters and return values are in host order,

 	* except SPI, which is always in network byte order.

 @verbatim

 Extract from RFC-2402

     0                   1                   2                   3

     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

    | Next Header   |  Payload Len  |          RESERVED             |

    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

    |                 Security Parameters Index (SPI)               |

    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

    |                    Sequence Number Field                      |

    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

    |                                                               |

    +                Authentication Data (variable)                 |

    |                                                               |

    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

 @endverbatim

 	* @publishedAll

 	* @released

 	*/

 	{

 public:

 	//

 	// Basic

 	//

 	inline static TInt MinHeaderLength() {return 3*4; }

 	inline static TInt MaxHeaderLength() {return 3*4; }

 	inline TUint8 *EndPtr() {return i + HeaderLength();}

 	//

 	// Access, get values

 	//

 	inline TInt NextHeader() const

 		{

 		return i[0];

 		}

 	//

 	// PayloadLength returns the raw value

 	//

 	inline TInt PayloadLength() const

 		{

 		return i[1];

 		}

 	//

 	// *NOTE* AH is called IPv6 extension header, but its

 	// length field semantics does not follow the normal

 	// IPv6 extension header logic (it follows the IPv4)

 	//

 	inline TInt HeaderLength() const

 		{

 		return (i[1]+2) << 2;	// IPv4 and IPv6

 		}

 	//

 	// SPI is returned in network byte order

 	//

 	inline TUint32 SPI() const

 		{

 		return *((TUint32 *)(i + 4));

 		}

 	inline TUint32 Sequence() const

 		{

 		return (i[8] << 24) | (i[9] << 16) | (i[10] << 8) | i[11];

 		}

 	// The length of the Authentication Data (in octets).

 	// *NOTE* This will include the potential padding! -- msa

 	inline TInt DataLength() const		{

 		return HeaderLength() - 12;

 		}

 	inline TPtr8 ICV()

 		{

 		return TPtr8((TUint8 *)&i[12], DataLength(), DataLength());

 		}

 	//

 	// Build

 	//

 	inline void SetNextHeader(TInt aNext)

 		{

 		i[0] = (TUint8)aNext;

 		}

 	inline void SetPayloadLength(TInt aByte)

 		{

 		i[1] = (TUint8)aByte;

 		}

 	//

 	// *NOTE* AH is called IPv6 extension header, but its

 	// length field semantics does not follow the normal

 	// IPv6 extension header logic (it follows the IPv4)

 	// As this is bit tricky, a "cooked version" of PayloadLength

 	// setting is also provided (e.g. take in bytes, and compute

 	// the real payload length value) -- msa

 	inline void SetHeaderLength(TInt aLength)

 		{

 		i[1] = (TUint8)((aLength >> 2) - 2);

 		}

 	inline void SetSPI(TUint32 aSPI)

 		{

 		*((TUint32 *)(i + 4)) = aSPI;

 		}

 	inline void SetReserved(TInt aValue)

 		{

 		i[3] = (TUint8)aValue;

 		i[2] = (TUint8)(aValue >> 8);

 		}

 	inline void SetSequence(TUint32 aSeq)

 		{

 		i[11] = (TUint8)aSeq;

 		i[10] = (TUint8)(aSeq >> 8);

 		i[9] = (TUint8)(aSeq >> 16);

 		i[8] = (TUint8)(aSeq >> 24);

 		}

 protected:

 	union

 		{

 		TUint8 i[3*4];

 		TUint32 iAlign;	// A dummy member to force the 4 byte alignment

 		};

 	};

 class TInet6HeaderESP

 	/**

 	* IPsec Encapsulating Security Payload Packet Format.

 	*

 	* The function parameters and return values are in host

 	* order (except SPI, which is always in network byte order)

 	*

 @verbatim

 RFC-2406

  0                   1                   2                   3

  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ----

 |               Security Parameters Index (SPI)                 | ^Auth.

 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Cov-

 |                      Sequence Number                          | |erage

 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ----

 |                    Payload Data* (variable)                   | |   ^

 ~                                                               ~ |   |

 |                                                               | |Conf.

 +               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Cov-

 |               |     Padding (0-255 bytes)                     | |erage*

 +-+-+-+-+-+-+-+-+               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |   |

 |                               |  Pad Length   | Next Header   | v   v

 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ------

 |                 Authentication Data (variable)                |

 ~                                                               ~

 |                                                               |

 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

 @endverbatim

 	* This only defines the fixed portion of the ESP, 8 bytes).

 	* @publishedAll

 	* @released

 	*/

 	{

 public:

 	//

 	// Basic

 	//

 	inline static TInt MinHeaderLength() {return 2*4; }

 	inline static TInt MaxHeaderLength() {return 2*4; }

 	inline TInt HeaderLength() const {return 2*4; }

 	inline TUint8 *EndPtr() {return i + HeaderLength();}

 	//

 	// Access, get values

 	//

 	//

 	// SPI is returned in network byte order

 	//

 	inline TUint32 SPI() const

 		{

 		return *((TUint32 *)(i + 0));

 		}

 	inline TUint32 Sequence() const

 		{

 		return (i[4] << 24) | (i[5] << 16) | (i[6] << 8) | i[7];

 		}

 	//

 	// IV is not exactly part of the header, but provide

 	// a method that returns a Ptr to it (assuming the

 	// IV is accessible directly after the fixed part).

 	//

 	inline TPtr8 IV(TInt aLen)

 		{

 		return TPtr8((TUint8 *)&i[sizeof(i)], aLen, aLen);

 		}

 	//

 	// Build

 	//

 	inline void SetSPI(TUint32 aSPI)

 		{

 		*((TUint32 *)(i + 0)) = aSPI;

 		}

 	inline void SetSequence(TUint32 aSeq)

 		{

 		i[7] = (TUint8)aSeq;

 		i[6] = (TUint8)(aSeq >> 8);

 		i[5] = (TUint8)(aSeq >> 16);

 		i[4] = (TUint8)(aSeq >> 24);

 		}

 protected:

 	union

 		{

 		TUint8 i[2*4];

 		TUint32 iAlign;	// A dummy member to force the 4 byte alignment

 		};

 	};

 /** @} */

 #endif