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/* SCF.h
* * Copyright (c) 1994-1995 by DataBeam Corporation, Lexington, KY * * Abstract: * This class represents the Network layer in the T.123 Transport stack. * This layer communicates over the DataLink layer (DLCI 0). It sends the * necessary packets to start a connection. It is also responsible for * disconnecting the connection. * * During arbitration of a connection, SCF arbitrates priority and DataLink * parameters. SCF instantiates a SCFCall object for each active logical * connection. Remotely initiated calls are placed in the * Remote_Call_Reference array while locally initiated calls are kept in * the Call_Reference array. * * This class inherits from ProtocolLayer although it assumes that it does * not have a higher layer to pass packets to. The T.123 document is clear * about that during the user data transmission, this layer has no purpose. * * Caveats: * None. * * Authors: * James W. Lawwill */
#ifndef _SCF_H_
#define _SCF_H_
#include "q922.h"
#include "scfcall.h"
/*
** SCF Errors */typedef enum{ SCF_NO_ERROR, SCF_NO_SUCH_DLCI, SCF_CONNECTION_FULL, SCF_MEMORY_ALLOCATION_ERROR} SCFError;
#define TRANSPORT_HASHING_BUCKETS 3
/*
** Offsets into packet */#define PROTOCOL_DISCRIMINATOR 0
#define LENGTH_CALL_REFERENCE 1
#define CALL_REFERENCE_VALUE 2
/*
** Supported commands */#define NO_PACKET 0x00
#define CONNECT 0x07
#define CONNECT_ACKNOWLEDGE 0x0f
#define SETUP 0x05
#define RELEASE_COMPLETE 0x5a
/*
** Unsupported commands as stated by T.123 */#define RELEASE 0x4d
#define ALERTING 0x01
#define CALL_PROCEEDING 0x02
#define PROGRESS 0x03
#define DISCONNECT 0x45
#define SEGMENT 0x40
#define STATUS 0x5d
#define STATUS_ENQUIRY 0x55
/*
** Packet Elements, not all of these are supported. */#define BEARER_CAPABILITY 0x04
#define DLCI_ELEMENT 0x19
#define END_TO_END_DELAY 0x42
#define LINK_LAYER_CORE_PARAMETERS 0x48
#define LINK_LAYER_PROTOCOL_PARAMETERS 0x49
#define X213_PRIORITY 0x50
#define CALLING_PARTY_SUBADDRESS 0x6d
#define CALLED_PARTY_SUBADDRESS 0x71
#define CAUSE 0x08
#define EXTENSION 0x80
/*
** Remote Call Reference */#define REMOTE_CALL_REFERENCE 0x80
/*
** Bearer Capability definitions */#define CODING_STANDARD 0
#define INFORMATION_TRANSFER_CAPABILITY 0x08
#define TRANSFER_MODE 0x20
#define LAYER_2_IDENT 0x40
#define USER_INFORMATION_LAYER_2 0x0e
/*
** DLCI element */#define PREFERRED_EXCLUSIVE 0x40
/*
** Link Layer Core Parameters */#define FMIF_SIZE 0x09
#define THROUGHPUT 0x0a
#define MINIMUM_THROUGHPUT 0x0b
#define COMMITTED_BURST_SIZE 0x0d
#define EXCESS_BURST_SIZE 0x0e
/*
** Link Layer Protocol Parameters */#define TRANSMIT_WINDOW_SIZE_IDENTIFIER 0x07
#define RETRANSMISSION_TIMER_IDENTIFIER 0x09
/*
** Q.850 Error messages, these are the only 2 errors we currently support */#define REQUESTED_CHANNEL_UNAVAILABLE 0x2c
#define NORMAL_USER_DISCONNECT 0x1f
/*
** Single Octet information elements */#define SINGLE_OCTET_ELEMENT_MASK 0x80
#define Q931_PROTOCOL_DISCRIMINATOR 0x08
#define CALL_REFERENCE_ORIGINATOR 0x80
#define CALL_ORIGINATOR_MASK 0x7f
/*
** T303 is the timeout allowed from the time we send the SETUP until we receive ** a response */#define DEFAULT_T303_TIMEOUT 30000
/*
** T313 is the timeout allowed from the time we send the CONNECT until we ** receive a response */#define DEFAULT_T313_TIMEOUT 30000
class CLayerSCF : public IProtocolLayer{public:
CLayerSCF( T123 *owner_object, CLayerQ922 *lower_layer, USHORT message_base, USHORT identifier, BOOL link_originator, PDataLinkParameters datalink, PMemoryManager memory_manager, BOOL * initialized);
virtual ~CLayerSCF(void);
SCFError ConnectRequest ( DLCI dlci, TransportPriority priority); SCFError DisconnectRequest ( DLCI dlci); SCFError ConnectResponse ( CallReference call_reference, DLCI dlci, BOOL valid_dlci);
/*
** Functions overridden from the ProtocolLayer object */ ProtocolLayerError DataRequest ( ULONG_PTR identifier, LPBYTE buffer_address, ULONG length, PULong bytes_accepted); ProtocolLayerError DataRequest ( ULONG_PTR identifier, PMemory memory, PULong bytes_accepted); ProtocolLayerError DataIndication ( LPBYTE buffer_address, ULONG length, PULong bytes_accepted); ProtocolLayerError RegisterHigherLayer ( ULONG_PTR identifier, PMemoryManager dr_memory_manager, IProtocolLayer * higher_layer); ProtocolLayerError RemoveHigherLayer ( ULONG_PTR identifier); ProtocolLayerError PollTransmitter ( ULONG_PTR identifier, USHORT data_to_transmit, USHORT * pending_data, USHORT * holding_data); ProtocolLayerError PollReceiver(void); ProtocolLayerError GetParameters ( USHORT * max_packet_size, USHORT * prepend, USHORT * append);
ULONG OwnerCallback(ULONG, void *p1 = NULL, void *p2 = NULL, void *p3 = NULL);
private:
CallReference GetNextCallReference (void);
void ProcessMessages (void);
private:
DictionaryClass Remote_Call_Reference; DictionaryClass Call_Reference; DictionaryClass DLCI_List; SListClass Message_List;
T123 *m_pT123; // owner object
CLayerQ922 *m_pQ922; // lower layer
USHORT m_nMsgBase; USHORT Identifier; USHORT Link_Originator; USHORT Maximum_Packet_Size; DataLinkParameters DataLink_Struct; PMemoryManager Data_Request_Memory_Manager; USHORT Lower_Layer_Prepend; USHORT Lower_Layer_Append; USHORT Call_Reference_Base;};typedef CLayerSCF * PSCF;
#endif
/*
* Documentation for Public class members */
/*
* CLayerSCF::CLayerSCF ( * PTransportResources transport_resources, * IObject * owner_object, * IProtocolLayer * lower_layer, * USHORT message_base, * USHORT identifier, * BOOL link_originator, * PChar config_file, * PDataLinkParameters datalink, * PMemoryManager memory_manager, * BOOL * initialized); * * Functional Description * This is the constructor for the SCF Network layer. It registers itself * with the lower so that incoming data will be received properly. * * Formal Parameters * transport_resources (i) - Pointer to TransportResources structure. * owner_object (i) - Address of the object that owns this object * lower_layer (i) - Address of the layer below us. * message_base (i) - Message base used in owner callbacks. * identifier (i) - This objects identification number. Passed to * lower layer to identify us (DLCI 0). * link_originator (i) - BOOL, TRUE if we started the link * config_file (i) - Address of the configuration path string * datalink (i) - Address structure holding the DataLink * arbitratable parameters. * memory_manager (i) - Address of the memory manager * initialized (o) - Address of BOOL, we set it to TRUE if it * worked * * Return Value * None * * Side Effects * None * * Caveats * None * */
/*
* CLayerSCF::~CLayerSCF (void); * * Functional Description * This is the destructor for the SCF Network layer. We do our * cleanup in here * * Formal Parameters * None * * Return Value * None * * Side Effects * None * * Caveats * None */
/*
* SCFError CLayerSCF::ConnectRequest ( * DLCI dlci, * USHORT priority) * * Functional Description * This function initiates a connection with the remote site. As a result, * we will create a SCFCall and tell it to initiate a connection. * * Formal Parameters * dlci (i) - Proposed DLCI for the connection * priority (i) - Proposed priority for the connection * * Return Value * SCF_NO_ERROR - No erroro occured * * Side Effects * None * * Caveats * None * */
/*
* SCFError CLayerSCF::DisconnectRequest ( * DLCI dlci); * * Functional Description * This function starts the disconnect process. * * Formal Parameters * dlci (i) - DLCI to disconnect. * * Return Value * SCF_NO_ERROR - No error occured * SCF_NO_SUCH_DLCI - Invalid DLCI * * Side Effects * None * * Caveats * None * */
/*
* SCFError CLayerSCF::ConnectResponse ( * CallReference call_reference, * DLCI dlci, * BOOL valid_dlci); * * Functional Description * This function is called by a higher layer to confirm a connection. If * the remote site initiates a connection with us, we issue a * NETWORK_CONNECT_INDICATION to the owner object. It responds with this * call to confirm or deny the suggested dlci. * * Formal Parameters * call_reference (i) - Call reference ID, passed to owner in * NETWORK_CONNECT_INDICATION * dlci (i) - Referenced DLCI * valid_dlci (i) - TRUE if the requested DLCI is valid * * Return Value * SCF_NO_ERROR - No error occured * * Side Effects * None * * Caveats * None * */
/*
* ProtocolLayerError CLayerSCF::DataRequest ( * ULONG identifier, * LPBYTE buffer_address, * USHORT length, * USHORT * bytes_accepted); * * Functional Description * This function is called by a higher layer to request transmission of * a packet. For the SCF, this functio is not used * * Formal Parameters * identifier (i) - Identifier of the higher layer * buffer_address (i) - Buffer address * length (i) - Length of packet to transmit * bytes_accepted (o) - Number of bytes accepted by the Multiplexer. * This value will either be 0 or the packet * length since this layer is a packet to byte * converter. * * Return Value * PROTOCOL_LAYER_ERROR * * Side Effects * None * * Caveats * None * */
/*
* ProtocolLayerError CLayerSCF::DataRequest ( * ULONG, * PMemory, * USHORT *) * * Functional Description * This function is not used. * * Formal Parameters * No parameters used * * Return Value * PROTOCOL_LAYER_ERROR * * Side Effects * None * * Caveats * None * */
/*
* ProtocolLayerError Multiplexer::DataIndication ( * LPBYTE buffer_address, * USHORT length, * USHORT * bytes_accepted); * * Functional Description * This function is called by the lower layer when it has data to pass up * * Formal Parameters * buffer_address (i) - Buffer address * length (i) - Number of bytes available * bytes_accepted (o) - Number of bytes accepted * * Return Value * PROTOCOL_LAYER_NO_ERROR - No error occured * * Side Effects * None * * Caveats * None * */
/*
* ProtocolLayerError CLayerSCF::RegisterHigherLayer ( * ULONG identifier, * IProtocolLayer * higher_layer); * * Functional Description * This function is called by the higher layer to register its identifier * and its address. In some cases, the identifier is the DLCI number in * the packet. If this multiplexer is being used as a stream to packet * converter only, the identifer is not used and all data is passed to the * higher layer. This is a NULL function by SCF * * Formal Parameters * identifier (i) - Identifier used to identify the higher layer * higher_layer (i) - Address of higher layer * * Return Value * PROTOCOL_LAYER_NO_ERROR - No higher layer allowed * * Side Effects * None * * Caveats * None * */
/*
* ProtocolLayerError CLayerSCF::RemoveHigherLayer ( * ULONG identifier); * * Functional Description * This function is called by the higher layer to remove the higher layer. * If any more data is received with its identifier on it, it will be * trashed. This is a NULL function for SCF * * Formal Parameters * identifier (i) - Identifier used to identify the higher layer * * Return Value * PROTOCOL_LAYER_REGISTRATION_ERROR - No higher layer allowed * * Side Effects * None * * Caveats * None * */
/*
* ProtocolLayerError CLayerSCF::PollTransmitter ( * ULONG identifier, * USHORT data_to_transmit, * USHORT * pending_data, * USHORT * holding_data); * * Functional Description * This function is called to give SCF a chance transmit data * in its Data_Request buffer. * * Formal Parameters * identifier (i) - Not used * data_to_transmit (i) - This is a mask that tells us to send Control * data, User data, or both. Since the * SCF does not differentiate between * data types it transmits any data it has * pending_data (o) - Return value to indicat which data is left * to be transmitted. * * Return Value * PROTOCOL_LAYER_NO_ERROR - No error occured * * Side Effects * None * * Caveats * None * */
/*
* ProtocolLayerError CLayerSCF::PollReceiver ( * ULONG identifier); * * Functional Description * This function is called to give SCF a chance pass packets * to higher layers. It is not used in SCF. * * Formal Parameters * identifier (i) - Not used * * Return Value * PROTOCOL_LAYER_NO_ERROR - No error occured * * Side Effects * None * * Caveats * None * */
/*
* ProtocolLayerError CLayerSCF::GetParameters ( * ULONG identifier, * USHORT * max_packet_size, * USHORT * prepend, * USHORT * append); * * Functional Description * This function is called to get the maximum packet size. This function * is not used in SCF. It is here because we inherit from ProtocolLayer * and this is a pure virtual function in that class. * * Formal Parameters * identifier (i) - Not used * max_packet_size (o) - Returns the maximum packet size * prepend (o) - Number of bytes prepended to a packet * append (o) - Number of bytes appended to a packet * * Return Value * PROTOCOL_LAYER_REGISTRATION_ERROR - Function can not be called * * Side Effects * None * * Caveats * None * */
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