/*
*@param Data to be sent
*@param Data size
*@param Frame to be created
*@ret int -> Total frame size
*/
int createInformationFrame(char* data, size_t dataSize, char* frame) {
char* stuffInfo = (char*)malloc(sizeof(char)*MAX_FRAME_SIZE);
frame[0] = FLAG; // estava F
frame[1] = FRAME_A_T ; // estava A
frame[2] = FRAME_C_SET; // estava SETUP
frame[3] = FRAME_A_T ^ FRAME_C_SET; // estava BCC1
char BCC2 = data[0];
int i;
for(i = 0; i < dataSize; i++) {
BCC2 ^= data[i];
}
int size = byteStuffing(data, dataSize, stuffInfo);
memcpy(&frame[4], stuffInfo, size);
frame[size + 4] = BCC2;
frame[size + 5] = FLAG;
return (size+6);
}
int llwrite(int fd, unsigned char * buffer, unsigned int length) {
if (linklayer.flag == RECEIVER) {
printf("RECEIVER CANNOT WRITE TO SERIAL PORT\n");
return -1;
}
if (!initialized) {
printf("SERIAL PORT ISNT INITIALIZED\n");
return -1;
}
unsigned char bcc2 = 0;
generate_bcc2(buffer, length, &bcc2);
unsigned char aux_buffer[MAX_SIZE] = "";
memcpy(aux_buffer, buffer, length);
printf("bcc2 wrote: %x\n",bcc2);
aux_buffer[length] = bcc2;
unsigned char * stuffed_buffer = malloc(MAX_SIZE);
int stuffed_length = 0;
if ((stuffed_length = byteStuffing(aux_buffer, length+1, stuffed_buffer)) == -1) {
printf("BYTE STUFFING ERROR\n");
return -1;
}
int nbytes = 0;
printf("sending data!\n");
nbytes = send_data(fd, stuffed_buffer, stuffed_length);
printf("wrote: %d bytes",nbytes);
if (rec_resp_receiver(fd, stuffed_buffer, stuffed_length, bcc2) == -1) {
printf("\n");
return -1;
}
free(stuffed_buffer);
linklayer.sequenceNumber = NEXT_INDEX(linklayer.sequenceNumber);
return nbytes;
}
int llwrite(int fd, unsigned char* buffer, int length){
//printf("entrei no llwrite\n");
char *bufferStuffed;
char header[] = { FLAG, 0x03, I(ll.sequenceNumber), header[1]^header[2] };
char dataBCC = generateBCC((char*)buffer, length);
char* toStuff = malloc(length+1);
memcpy(toStuff, buffer, length);
toStuff[length] = dataBCC;
int n= byteStuffing(toStuff, length+1, &bufferStuffed);
//int k;
//puts("");
//for (k=0;k<n;k++){
//printf("\n%d\n", bufferStuffed[k]);
//}
// puts("");
char* message = (char*) malloc(n+6);
memcpy(message, header, 4);
memcpy(message+4, bufferStuffed, n);
message[n+4] = FLAG;
int wrote = 0;
while(!wrote)
wrote = write(fd, message, n+5);
stats.dataFramesTransmitted++;
//puts("message sent\n");
free(message);
free(bufferStuffed);
alarm(ll.timeOut);
Command command = receiveCommand(fd);
//was asked for new frame
if (command.command == RR(!ll.sequenceNumber)){
ll.sequenceNumber = (!ll.sequenceNumber);
retries = 0;
//puts("fui confirmado");
alarm(0);
return length;
}
//frame was rejected, resend
if (command.command == REJ(ll.sequenceNumber) || (command.command == NONE && ll.numTransmissions > retries)){
if (command.command == NONE){
stats.timeouts++;
//printf("\nNumber of retries: %d\n", retries);
alarm(0);
}
//puts("byte was rejected,resending or no response\n");
stats.rejs++;
return llwrite(fd, buffer, length);
}
else{
//puts("eu esperei mas o reader nao me quis responder :(");
return -1;
}
return length;
}
