Source code of Windows XP (NT5)
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/*
* packet.h
*
* Copyright (c) 1993 - 1995 by DataBeam Corporation, Lexington, KY
* 1997 by Microsoft Corporation, Redmond, WA
*
* Abstract:
* This is the interface file for the Packet class. Instances of this
* class represent Protocol Data Units (PDUs) as they flow through the
* system. These instances manage the memory required to hold both
* encoded and decoded versions of the PDU, and make sure that no PDU
* is ever encoded or decoded more than once. The use of lock counts
* allow multiple objects in the system to reference and use the same
* packet object at the same time. This class inherits from the SimplePacket
* class (a pure virtual class).
*
* A packet object can be created in 2 different ways. It can be created
* with either decoded data or encoded data. During instantiation, the
* new packet object will calculate how much memory it will need to
* hold both the encoded and decoded data, and attempts to allocate that
* memory. If it cannot, then it will report an error, and the newly
* created object should be immediately destroyed. If the allocations are
* successful, then the packet will report success, but WILL NOT yet put
* any data into those allocated buffers.
*
* When a Lock message is sent to the object, it will put encoded
* data into the pre-allocated encode buffer. If the packet was created
* with decoded data, then this will entail an encode operation. However,
* if the packet was created with encoded data, then it is smart enough
* to just COPY the encoded data into the internal buffer, thus avoiding
* the overhead associated with the encode operation.
*
* When a Lock message is sent to the object, it will put decoded
* data into the pre-allocated decode buffer. If the packet was created
* with encoded data, then this will entail a decode operation. However,
* if the packet was created with decoded data, then it is smart enough
* to just COPY the decoded data into the internal buffer, thus avoiding
* the overhead associated with the decode operation.
*
* When Unlock messages are received, the lock count is decremented. When
* the lock count is 0, the packet deletes itself (it commits
* suicide). Note that for this reason, no other object should explicitly
* delete a packet object.
*
* Caveats:
* None.
*
* Authors:
* James J. Johnstone IV
* Christos Tsollis
*/
#ifndef _PACKET_
#define _PACKET_
#include "pktcoder.h"
/*
* Definition of class Packet.
*/
class Packet;
typedef Packet * PPacket;
class Packet : public SimplePacket
{
public:
// outgoing packets
Packet(PPacketCoder pPacketCoder,
UINT nEncodingRules,
LPVOID pInputPduStructure,
int nPduType,
BOOL fPacketDirectionUp,
PPacketError pePktErr,
BOOL fLockEncodedData = FALSE);
// incoming packets
Packet(PPacketCoder pPacketCoder,
UINT nEncodingRules,
LPBYTE pEncodedData,
UINT cbEncodedDataSize,
int nPduType,
BOOL fPacketDirectionUp,
PPacketError pePktErr);
virtual ~Packet(void);
virtual BOOL IsDataPacket (void);
virtual PVoid GetDecodedData(void);
UINT GetDecodedDataLength(void) { return Decoded_Data_Length; };
virtual int GetPDUType(void);
protected:
PPacketCoder Packet_Coder;
LPVOID m_Decoded_Data;
UINT Decoded_Data_Length;
int PDU_Type;
};
/*
* Packet (
* PPacketCoder packet_coder,
* UINT encoding_rules,
* PVoid pInputPduStructure,
* PMemory pInputPduStructure_Memory,
* int pdu_type,
* DBBoolean packet_direction_up,
* PPacketError return_value )
*
* Functional Description:
* This version of the constructor is used to create a Packet object
* for outgoing PDUs when the packet is to be created from a structure
* containing the PDU data to be encoded.
*
* Formal Parameters:
* packet_coder (i)
* Pointer to the packet coder object. This pointer will be used by
* the packet object to encode and decode PDU structures. This pointer
* must not become stale during the life of the packet object.
* encoding_rules (i)
* This value identifies which set of encoding rules should be used
* on the current packet. This is simply through to the packet coder
* during all encode and decode operations.
* pInputPduStructure (i)
* Pointer to the input PDU structure.
* pInputPduStructure_Memory
* Pointer to a Memory struct for the buffer containing the pdu structure.
* Exactly one of the args pInputPduStructure_Memory and pInputPduStructure
* should be non-NULL;
* pdu_type (i)
* The type of PDU contained in the packet. This is passed through
* to the packet coder specified above.
* packet_direction_up (i)
* The packet_direction_up flag indicates the initial orientation of
* the packet. Valid values are:
* TRUE - The packet's direction is up.
* FALSE - The packet's direction is down.
* return_value (o)
* When the constructor returns control to the calling function, this
* variable will be set to one of the return values listed below.
*
* Return Value:
* PACKET_NO_ERROR
* The Packet object was constructed correctly.
* PACKET_MALLOC_FAILURE
* The constructor was unable to allocate the memory required to work
* properly. The Packet object should be deleted.
*
* Side Effects:
* None.
*
* Caveats:
* None.
*/
/*
* Packet (
* PPacketCoder packet_coder,
* UINT encoding_rules,
* PUChar encoded_data_ptr,
* UShort encoded_data_length,
* int pdu_type,
* DBBoolean packet_direction_up,
* PPacketError return_value )
*
* Functional Description:
* This version of the constructor is used to create a Packet object
* for incomming PDUs when the packet is to be created from an encoded
* data stream containing the PDU data to be decoded.
*
* Formal Parameters:
* packet_coder (i)
* Pointer to the packet coder object. This pointer will be used by
* the packet object to encode and decode PDU structures. This pointer
* must not become stale during the life of the packet object.
* encoding_rules (i)
* This value identifies which set of encoding rules should be used
* on the current packet. This is simply through to the packet coder
* during all encode and decode operations.
* encoded_data_ptr (i)
* Pointer to the input encoded PDU.
* encoded_data_length (i)
* The length in bytes of the input encoded PDU.
* pdu_type (i)
* The type of PDU contained in the packet. This is passed through
* to the packet coder specified above.
* packet_direction_up (i)
* The packet_direction_up flag indicates the initial orientation of
* the packet. Valid values are:
* TRUE - The packet's direction is up.
* FALSE - The packet's direction is down.
* return_value (o)
* When the constructor returns control to the calling function, this
* variable will be set to one of the return values listed below.
*
* Return Value:
* PACKET_NO_ERROR
* The Packet object was constructed correctly.
* PACKET_MALLOC_FAILURE
* The constructor was unable to allocate the memory required to work
* properly. The Packet object should be deleted.
*
* Side Effects:
* None.
*
* Caveats:
* None.
*/
/*
* ~Packet ()
*
* Functional Description:
* Destructor for the Packet class. The destructor ensures that all
* resources that have been allocated are freed.
*
* Formal Parameters:
* None.
*
* Return Value:
* None.
*
* Side Effects:
* None.
*
* Caveats:
* None.
*/
/*
* GetDecodedData ()
*
* Functional Description:
* The GetDecodedData method returns a pointer to the decoded data
* buffer.
*
* Formal Parameters:
* None.
*
* Return Value:
* A pointer to the decoded data. If an decoding error occurs, this
* method will return NULL.
*
* Side Effects:
* None.
*
* Caveats:
* None.
*/
/*
* GetDecodedDataLength ()
*
* Functional Description:
* This method returns the decoded data's length.
*
* Formal Parameters:
* None.
*
* Return Value:
* The number of bytes in the decoded data.
*
* Side Effects:
* None.
*
* Caveats:
* None.
*/
/*
* GetPDUType ()
*
* Functional Description:
* This method returns the PDU type.
*
* Formal Parameters:
* None.
*
* Return Value:
* Either DOMAIN_MCS_PDU or CONNECT_MCS_PDU dependant upon the PDU type.
*
* Side Effects:
* None.
*
* Caveats:
* None.
*/
#endif