ss7_mtp2.cpp

实现了SS7中MTP2层的基本功能

#define DIRECTION 1

// File Name: SS7_MTP2.cpp
/////////////////////////////////////////////////

#include "SS7_MTP2.h"
#include <stdlib.h>
#include <stdio.h>

int outFileIndex; // for UT

// The table of timer events: (FSM_X,EVENT_X)
//    If Timer X expired, FSM "FSM_X" will got event "EVENT_X"
MTP2_FSM_Event timer_events[7] = {
    {MTP2_FSM_LSC, (int)LSCEventT1Expired},
    {MTP2_FSM_IAC, (int)IACEventT2Expired},
    {MTP2_FSM_IAC, (int)IACEventT3Expired},
    {MTP2_FSM_IAC, (int)IACEventT4Expired},
    {MTP2_FSM_CC,  (int)CCEventT5Expired},
    {MTP2_FSM_TXC, (int)TXCEventT6Expired},
    {MTP2_FSM_TXC, (int)TXCEventT7Expired} };

// Corresponding to MTP2_FSM_TYPE, list the FSM handling functions
FSMFunc fsmProcessFunc[11] = {
            NULL, // MTP2_FSM_NULL,
            & SS7_MTP2::LSC, // MTP2_FSM_LSC,
            & SS7_MTP2::RC, // MTP2_FSM_RC,
            & SS7_MTP2::TXC, // MTP2_FSM_TXC,
            & SS7_MTP2::IAC, // MTP2_FSM_IAC,
            & SS7_MTP2::POC, // MTP2_FSM_POC,
            & SS7_MTP2::CC, // MTP2_FSM_CC,
            & SS7_MTP2::AERM, // MTP2_FSM_AERM,
            & SS7_MTP2::SUERM, // MTP2_FSM_SUERM,
            & SS7_MTP2::DAEDR, // MTP2_FSM_DAEDR,
            & SS7_MTP2::DAEDT }; // MTP2_FSM_DAEDT 

void SS7_MTP2::init_data_member(void)
{
    fd = -1;
    lscState = LSCStatePowerOff;
    iacState = IACStateIdle;
    emergency = false;
    portNumber = 0;
    recvHighWaterLevel = (int)(MTP2_RECV_BUF_SIZE * HIGH_WATER_LEVEL);
    recvMidWaterLevel = (int)(MTP2_RECV_BUF_SIZE * MID_WATER_LEVEL);

    errorRate = 0;

    pocState = POCStateIdle;
    txcState = TXCStateIdle;
    rcState = RCStateIdle;
    aermState = AERMStateIdle;
    suermState = SUERMStateIdle;
    ccState = CCStateIdle;
    daedrState = DAEDRStateIdle;
    daedtState = DAEDTStateIdle;

    Ti = Tin;

    // errorRate;

    octetCountingMode = false ;
    alignmentComplete = false ;
    emergency = false ;
    linkFailure = false ;
    localProcessorOutage = false ;
    processorOutage = false ;
    noProcessorOutage = true ;
    level3IndicationReceived = false ;

    LSSUAvailable = false ;
    SIBreceived = false ;
    RTBfull = false ;
    MSUinhibited = false ;

    TXC_FSNL = 127; // FSN of the last MSU in the RTB
    TXC_FSNT = 127; // FSN of the last MSU transmitted
    TXC_FSNX = 0; // FSN expected
    TXC_FIB = 1; // Forward indicator bit
    TXC_BIB = 1; // backward indicator bit
    TXC_FSNF = 0; // FSN of the oldest MSU in the RTB 
    Cm = 0; // Counter of MSU in TB

    RC_FSNX = 0;
    RC_FIBX = 1;

    RC_FSNF = 0;
    RC_FSNT = 127;
    RTR = 0; // If = 1 means retransmission expected

    FSNR = 0;
    FIBR = 1;
    BIBT = 1;
    BSNT = 127;
    FIBT = 1;
    BSNR = 127;
    BIBR = 1;
    FSNC = 127;
    UNB = 0;
    UNF = 0;

    Cp = 0;
    Ca = 0;
    Cs = 0;
    su = 0;

    furtherproving = true ;
    FISUMSUaccepted = false ;
    abnormalBSNR = false ;
    abnormalFIBR = false ;
    congestionDiscard = false ;
    congestionAccept = false ;

    for( int i=0 ; i<7 ; i++ )
    {
        timers[i].started = false;
    }
    timers[0].timer_val = T1;
    timers[1].timer_val = T2;
    timers[2].timer_val = T3;
    timers[3].timer_val = T4;
    timers[4].timer_val = T5;
    timers[5].timer_val = T6;
    timers[6].timer_val = T7;

    pSUWithLen = (SUWithLength *) malloc( sizeof(unsigned short)
                                          + sizeof(SUHeaderL2) + MAX_MSU_LEN );
    pSndSigUnit = (SndSigUnit *) malloc( sizeof(unsigned short) + sizeof(unsigned char)
                                     + sizeof(unsigned char) * 5 + sizeof(unsigned short)
                                     + 	sizeof(SUHeaderL2) + MAX_MSU_LEN );

    outFileIndex = 0; // for UT
    gettimeofday( & IACTimer, NULL );
    gettimeofday( & FISUTimer, NULL );
    gettimeofday( & LSCRestartTimer, NULL );
}

// will use 
SS7_MTP2::SS7_MTP2(int _portNumber) :
                recvBuffer(MTP2_RECV_BUF_SIZE),
                MSU2L3Buffer(MTP2_MSU2L3_BUF_SIZE),
                eventQueue(MTP2_EVENT_QUEUE),
                LSSUBuffer(MTP2_LSSU_BUF_SIZE),
                sendBuffer(MTP2_SEND_BUF_SIZE),
                resendBuffer(MTP2_SEND_BUF_SIZE)
{
    init_data_member();

    portNumber = _portNumber;
}

SS7_MTP2::SS7_MTP2(void) :
                recvBuffer(MTP2_RECV_BUF_SIZE),
                MSU2L3Buffer(MTP2_MSU2L3_BUF_SIZE),
                eventQueue(MTP2_EVENT_QUEUE),
                LSSUBuffer(MTP2_LSSU_BUF_SIZE),
                sendBuffer(MTP2_SEND_BUF_SIZE),
                resendBuffer(MTP2_SEND_BUF_SIZE)
{
    init_data_member();
}

SS7_MTP2::SS7_MTP2(int _portNumber,int _recvBufSize,int _msu2L3BufSize,
              int _sendBufSize,int _reLssuBufSize)
                : recvBuffer(_recvBufSize),
                  MSU2L3Buffer(_msu2L3BufSize),
                  eventQueue(MTP2_EVENT_QUEUE),
                  LSSUBuffer(_reLssuBufSize),
                  sendBuffer(_sendBufSize),
                resendBuffer(_sendBufSize)
{
    init_data_member();

    portNumber = _portNumber;
    recvHighWaterLevel = (int)(_recvBufSize * HIGH_WATER_LEVEL);
    recvMidWaterLevel = (int)(_recvBufSize * MID_WATER_LEVEL);
}

SS7_MTP2::~SS7_MTP2(void)
{
    if( pSUWithLen )
    {
        free( pSUWithLen );
    }

    if( pSndSigUnit )
    {
        free( pSndSigUnit );
    }

}

int SS7_MTP2::sendLSSU(void)
{
    return 0;
}

int SS7_MTP2::sendFISU(void)
{
    return 0;
}

int SS7_MTP2::sendSIO(void)
{
    return 0;
}

int SS7_MTP2::sendSIOS(void)
{
    return 0;
}

int SS7_MTP2::sendSIPO(void)
{
    return 0;
}

int SS7_MTP2::sendSIN(void)
{
    return sendSINorSIE(false);
}

int SS7_MTP2::sendSIE(void)
{
    return sendSINorSIE(true);
}

int SS7_MTP2::sendSINorSIE(bool _emergency)
{
    return 0;
}

// Initialize to work

int SS7_MTP2::poweron(void)
{
    printf("SS7_MTP2::poweron() !\n");

    MTP2_FSM_Event event_out;

    int n = 7;
    FILE * fpFlag = fopen( LOCAL_FLAG_FILE, "wb" );
    if( fpFlag == NULL )
    {
        printf("SS7_MTP2::poweron() -- Fail to write Flag file %s!\n", LOCAL_FLAG_FILE );
        // return 0;
    }
    else
    {
        fwrite( & n,  sizeof(int), 1, fpFlag );
        fclose( fpFlag );
    }

    AppendEvent( MTP2_FSM_TXC, TXCEventStart );
    AppendEvent( MTP2_FSM_TXC, TXCEventSendSIOS );

    // LSC --> AERM
    AppendEvent( MTP2_FSM_AERM, AERMEventSetTi2Tin );

    localProcessorOutage = false;
    emergency = false;

    lscState = LSCStateOutOfService;
    printf("SS7_MTP2::poweron() - Link(%d) state=LSCStateOutOfService!\n", portNumber );

    return 0;
}

int SS7_MTP2::start(void)
{
    printf("SS7_MTP2::start() !\n");

    LSC( LSCEventStart, 0 );
    return 0;
}

int SS7_MTP2::updateStates(void)
{
    // printf("SS7_MTP2::updateStates() !\n");

    // limit the number of events to be processed in one round ??
    // so that we could balance between link ports
    // now we process one event at once for each 

    MTP2_FSM_Event event;

    // read -- read out; seek -- ?
    if( lscState == LSCStateOutOfService )
    {
        struct timeval t;
        gettimeofday( & t, NULL );
        long diff = (t.tv_sec - LSCRestartTimer.tv_sec) * 1000000
                    + (t.tv_usec - LSCRestartTimer.tv_usec);

        if( diff > 1000000 ) // 1s        
        {
            LSCRestartTimer = t;
            LSC( LSCEventStart, 0 );
        }
    }

    if( eventQueue.read( (unsigned char *)& event, sizeof(MTP2_FSM_Event) ) == 0 )
    {
        // printf("SS7_MTP2::updateStates() - FSMType=%d,event=%d,param=%d!\n",
        //        event.FSMType, event.name, (unsigned int)event.param );
        if( fsmProcessFunc[event.FSMType] != NULL )
        {
            (this->*(fsmProcessFunc[event.FSMType]))( event.name, event.param );
        }
    }
    else
    {
        printf("SS7_MTP2::updateStates() - no event in the eventQueue!\n" );
        usleep( 100000 ); // 50ms, no event in the queue
        //return 0;
    }

    if( lscState == LSCStateInitialAlignment )
    {
        struct timeval t;
        gettimeofday( & t, NULL );
        long diff = (t.tv_sec - IACTimer.tv_sec) * 1000000 + (t.tv_usec - IACTimer.tv_usec);

        bool flag = true;
        FILE * fpFlag = fopen( REMOTE_FLAG_FILE, "rb" );
        if( fpFlag == NULL )
        {
         //   printf("SS7_MTP2::writeSUDowntoL() -- Flag file %s not there!\n",
         //        REMOTE_FLAG_FILE );
            flag = false;
        }
        else
        {
            fclose( fpFlag);
        }

        if( flag && (diff > 900000) ) {

            IACTimer = t;

            LSSU lssu;
            MTP2_FSM_Event event_out;

            BIBT = TXC_BIB;
            BSNT = (TXC_FSNX - 1 + 128) % 128;
            FIBT = TXC_FIB;

            lssu.suHeader.FSN = TXC_FSNT;
            lssu.suHeader.FIB = FIBT;
            lssu.suHeader.BSN = BSNT;
            lssu.suHeader.BIB = BIBT;

            lssu.suHeader.LI = 1;

            // populate the SndSigUnit
            pSndSigUnit->Length = SND_SU_HEADER_SIZE
                              + sizeof(SUHeaderL2) + lssu.suHeader.LI;
            pSndSigUnit->Type = 0;
            // pSndSigUnit->TimeStamp[0] = 0; // It's for L1 or L2 to populate?
            pSndSigUnit->ChName = (unsigned short)portNumber;

            switch( iacState )
            {
            case IACStateIdle:
                printf("SS7_MTP2::updateStates() - send repeated NONE - IACStateIdle!\n" );
                break;
            case IACStateNotAligned:
/*************************
                printf("SS7_MTP2::updateStates() - send repeated SIO - IACStateNotAligned!\n" );
                // sending SIO
                lssu.SF = LSSUTypeSIO;
                memcpy( (unsigned char *)pSndSigUnit->PktBuf,
                    (unsigned char *)& lssu, sizeof(SUHeaderL2) + lssu.suHeader.LI );
                writeSUDowntoL1( pSndSigUnit );
                // Need to append event to DAEDT? -- some extra msgs
**************************/
                break;
            case IACStateAligned:
            case IACStateProving:
                printf("SS7_MTP2::updateStates() - send repeated SIN/E - %s!\n",
                       (iacState == IACStateAligned) ? "IACStateAligned" : "IACStateProving" );
                // sending SIN/SIE
                lssu.SF = emergency ? LSSUTypeSIE : LSSUTypeSIN;
                memcpy( (unsigned char *)pSndSigUnit->PktBuf,
                    (unsigned char *)& lssu, sizeof(SUHeaderL2) + lssu.suHeader.LI );
                writeSUDowntoL1( pSndSigUnit );
                // Need to append event to DAEDT? -- some extra msgs
                break;
            default:               
                printf("SS7_MTP2::updateStates() - send NONE - default!\n" );
                break;
            }
        }
    }

    return 1; // processed 1 event
}