Ejemplos de crc_generate_key en C++ (Cpp)

Ejemplo n.º 1

Archivo: crc_benchmark.c Proyecto: 0xLeo/liquid-dsp

// Helper function to keep code base small
void crc_bench(struct rusage *_start,
               struct rusage *_finish,
               unsigned long int *_num_iterations,
               crc_scheme _crc,
               unsigned int _n)
{
    // normalize number of iterations
    if (_crc != LIQUID_CRC_CHECKSUM)
        *_num_iterations /= 8;

    unsigned long int i;

    // create arrays
    unsigned char msg[_n];
    unsigned int key = 0;

    // initialze message
    for (i=0; i<_n; i++)
        msg[i] = rand() & 0xff;

    // start trials
    getrusage(RUSAGE_SELF, _start);
    for (i=0; i<(*_num_iterations); i++) {
        key ^= crc_generate_key(_crc, msg, _n);
        key ^= crc_generate_key(_crc, msg, _n);
        key ^= crc_generate_key(_crc, msg, _n);
        key ^= crc_generate_key(_crc, msg, _n);
    }
    getrusage(RUSAGE_SELF, _finish);
    *_num_iterations *= 4;
}

Ejemplo n.º 2

Archivo: crc_autotest.c Proyecto: Clivia/liquid-dsp

// 
// autotest helper function
//
void validate_crc(crc_scheme _check,
                  unsigned int _n)
{
    unsigned int i;

    // generate pseudo-random data
    unsigned char data[_n];
    msequence ms = msequence_create_default(9);
    for (i=0; i<_n; i++)
        data[i] = msequence_generate_symbol(ms,8);
    msequence_destroy(ms);

    // generate key
    unsigned int key = crc_generate_key(_check, data, _n);

    // contend data/key are valid
    CONTEND_EXPRESSION(crc_validate_message(_check, data, _n, key));

    //
    unsigned char data_corrupt[_n];
    unsigned int j;
    for (i=0; i<_n; i++) {
        for (j=0; j<8; j++) {
            // copy original data sequence
            memmove(data_corrupt, data, _n*sizeof(unsigned char));

            // flip bit j at byte i
            data[i] ^= (1 << j);

            // contend data/key are invalid
            CONTEND_EXPRESSION(crc_validate_message(_check, data, _n, key)==0);
        }
    }
}

Ejemplo n.º 3

Archivo: packetizer.c Proyecto: 0xLeo/liquid-dsp

// Execute the packetizer on an input message
//
//  _p      :   packetizer object
//  _msg    :   input message (uncoded bytes)
//  _pkt    :   encoded output message
void packetizer_encode(packetizer _p,
                       unsigned char * _msg,
                       unsigned char * _pkt)
{
    unsigned int i;

    // copy input message to internal buffer[0]
    memmove(_p->buffer_0, _msg, _p->msg_len);

    // compute crc, append to buffer
    unsigned int key = crc_generate_key(_p->check, _p->buffer_0, _p->msg_len);
    for (i=0; i<_p->crc_length; i++) {
        // append byte to buffer
        _p->buffer_0[_p->msg_len+_p->crc_length-i-1] = key & 0xff;

        // shift key by 8 bits
        key >>= 8;
    }

    // execute fec/interleaver plans
    for (i=0; i<_p->plan_len; i++) {
        // run the encoder: buffer[0] > buffer[1]
        fec_encode(_p->plan[i].f,
                   _p->plan[i].dec_msg_len,
                   _p->buffer_0,
                   _p->buffer_1);

        // run the interleaver: buffer[1] > buffer[0]
        interleaver_encode(_p->plan[i].q,
                           _p->buffer_1,
                           _p->buffer_0);
    }

    // copy result to output
    memmove(_pkt, _p->buffer_0, _p->packet_len);
}