292 lines
8.6 KiB
C++
292 lines
8.6 KiB
C++
/*
|
|
* 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
|