File content as of revision 1:7c424a3e12ea:

#include "ipserver.h"

void printCadena(char* cad, int lenc){
    
    printf("\r\n");
    for (int i=0; i<lenc; i++){
        
        printf("cad[%d] = %d\r\n", i, cad[i]);
        }
    
    }

IpData::IpData(char* tx_buffer){
    
    this->id = ID_DEV;
    this->isValidData = false;
    
    this->len_tx_data = 0;
    this->tx_buff = tx_buffer;
    
    }
    
char* IpData::__findHeader(char* buffer){
    /*
    Find header and get ip data (without header)
    
    Input:
    
    Return:
        valid_ipdata:   ip data without header
        
        Example:
        
        buffer = [ B0 B1 $ J R O $ B7 B8 B9 B10 ..... ]
        
        return
            valid_ip_data = [ B7 B8 B9 B10 ..... ]
        
    
    */
    char* valid_ip_data;
    
    //printf("\r\nSearching header in %s\r\n", buffer);
    
    //Finding header
    valid_ip_data = strstr(buffer, HEADER);
    
    if (valid_ip_data == NULL){
        printf("\r\nHeader was not found\r\n");   
        return NULL;
    }
    
    //printf("\r\nHeader was found %s\r\n", valid_ip_data);
    
    //printf("\r\nskipping header ...\r\n");
    
    valid_ip_data += 5;  //skip header
        
    return valid_ip_data;
    }

char IpData::__getXor( char* data, unsigned long len_data){
    
    char new_xor = 0;
    
    for(unsigned long i = 0; i < len_data; i++){
        new_xor = new_xor xor data[i];
        }
    
    return new_xor;
    }
    
int IpData::__verifyData( char* ip_data, unsigned long len_data){
    
    char new_xor = 0;
    
    new_xor = this->__getXor(ip_data, len_data);
    
    if (new_xor != 0){
        printf("\r\nInvalid XOR: %d\r\n", new_xor);
        return 0;
    }
        
    //printf("\r\nXOR verified successfully\r\n");
    return 1;
    }

int IpData::__getParameters(){
    return 1;
    }
    
char* IpData::encode(unsigned short cmd, char* payload, unsigned long len_payload){

    int head_size= strlen(HEADER);
    char xor_wr;
    
    //Copy header
    strcpy(tx_buff, HEADER);
    len_tx_data = len_payload + 5;     //Incluye la longitud de la data + 1B (id_class) + 1B (id_dev) + 2B (cmd) + 1B (xor)
    len_tx_buffer = len_tx_data + 9;     //Incluye 5 bytes del Header + 4 de la longitud
    
    tx_buff[0+head_size] = (len_tx_data >> 24) & 0xff;
    tx_buff[1+head_size] = (len_tx_data >> 16) & 0xff;
    tx_buff[2+head_size] = (len_tx_data >> 8) & 0xff; 
    tx_buff[3+head_size] = len_tx_data & 0xff; 
    
    tx_buff[4+head_size] = ID_CLASS;
    tx_buff[5+head_size] = ID_DEV;
    
    tx_buff[6+head_size] = (cmd >> 8) & 0xff; 
    tx_buff[7+head_size] = cmd & 0xff; 
    
    for (unsigned int i=0; i<len_payload; i++)
        tx_buff[8+head_size+i] = payload[i];
    
    xor_wr = this->__getXor(&tx_buff[0+head_size], len_tx_data+4-1);   //Incluir todos los bytes de datos mas los 4B de la longitud menos 1B del xor
    
    tx_buff[8+head_size+len_payload] = xor_wr;

    printf("\r\nTx Buffer = ");
    for(unsigned long i=0; i< len_tx_buffer; i++)
        printf("0x%x ", tx_buff[i]);
        
    return tx_buff;
    
    }
    
    
int IpData::decode( char* buffer, unsigned long len_buffer){
    
    char* ip_data;
    unsigned long len_data;
    
    this->isValidData = false;
    
    printf("\r\nRx Buffer = ");
    for(unsigned long i=0; i< len_buffer; i++)
        printf("0x%x ", buffer[i]);
    
    if (len_buffer < 13){
        printf("\r\nLongitud de la data insuficiente\r\n");
        return 0;
        }
        
    //Finding header and get ip data (without header)
    ip_data = this->__findHeader(buffer);
    
    if (ip_data == NULL)
        return 0;
    
    len_data = ip_data[0]*65536*256 + ip_data[1]*65536 + ip_data[2]*256 + ip_data[3];
    
    //printf("\r\nLen data = %d\r\n", len_data);
    
    this->rx_buff = ip_data;
    
    //len_data + 4 = longitud de toda la data (incluyendo los 4 bytes del campo len)
    if (not this->__verifyData(ip_data, len_data+4))
        return 0;
        
    //head = ip_data[0:5];
    this->id_class = ip_data[4];
    this->id_dev = ip_data[5];
    this->cmd = ip_data[6]*256 + ip_data[7];
    this->payload = ip_data + 8;
    this->len_payload = len_data - 5;       //1B id_class, 1B id_dev, 2B cmd y 1B xor
    this->xor_rd = ip_data[4+len_data-1];
    
    printf("\r\nID_CLASS = 0x%x, ID_DEV = 0x%x, CMD = 0x%x, XOR = 0x%x", id_class, id_dev, cmd, xor_rd);
    printf("\r\nPAYLOAD[0] = 0x%x, PYLD_LEN = 0x%x\r\n", payload[0], len_payload);
    
    if (this->id_class == ID_CLASS){
        this->isValidData = true;
    
        return 1;
        }
    
    return 0;
    
    }
    
char IpData::getIdClass(){
    
    if (not this->isValidData)
        return 0;
        
    return this->id_class;
    }
    
char IpData::getIdDevice(){
    
    if (not this->isValidData)
        return 0;
        
    return this->id_dev;
    }
    
unsigned short IpData::getCmd(){
    
    if (not this->isValidData)
        return 0;
        
    return this->cmd;
    }
    
unsigned long IpData::getPayloadLen(){
    
    if (not this->isValidData)
        return 0;
        
    return this->len_payload;
    }
    
char* IpData::getPayload(){
    
    if (not this->isValidData)
        return NULL;
        
    return this->payload;
    }
 
char* IpData::getTxData(){
        
    return this->tx_buff;
    }   
unsigned long IpData::getTxDataLen(){
        
    return this->len_tx_buffer;
    }