int llread(int fd, char * buffer) {
//printf("iniciar llread \n");
while(1) {
info->frameTempLength = readFrame(info->frameTemp);
char * type = NULL;
type = verifyFrameType(info->frameTemp);
if (type == "set") {
buildFrame(info->flag, "ua");
transmitirFrame(info->frameSend, info->frameSendLength);
continue;
}
else if (type == "I0" || type == "I1") {
destuffing(info->frameTemp, &info->frameTempLength);
//fprintf(stderr,"Destuffing ");
/*int bb;
for(bb = 0; bb < info->frameTempLength; bb++){
fprintf(stderr,"0x%x ", info->frameTemp[bb]);
}
fprintf(stderr,"\n");*/
if (verifyFrame(info->frameTemp, info->frameTempLength, type)) {
if(type == "I0" && !info->sequenceNumber
|| type == "I1" && info->sequenceNumber) {
//printf("recebeu a trama I correspondente aos sequenceNumber %d \n", info->sequenceNumber);
char * typeRR = malloc(5);
sprintf(typeRR, "rr%d", !info->sequenceNumber);
//printf("criar frame de %s \n", typeRR);
buildFrame(info->flag, typeRR);
transmitirFrame(info->frameSend, info->frameSendLength);
free(typeRR);
info->sequenceNumber = !info->sequenceNumber;
}
else {
char * typeRR = malloc(5);
sprintf(typeRR, "rr%d", info->sequenceNumber);
//printf("criar frame de %s \n", typeRR);
buildFrame(info->flag, typeRR);
transmitirFrame(info->frameSend, info->frameSendLength);
free(typeRR);
continue;
}
int j;
//printf("frameTempLength: %d\n", info->frameTempLength);
//printf("dados recebidos: ");
for(j = 0; j < (info->frameTempLength-6); j++) {
info->dados[j] = info->frameTemp[4+j];
//printf(" %x ", info->dados[j]);
buffer[j] = info->dados[j];
//printf(" %x \n", info->dados[j]);
}
//printf("\n");
info->lengthDados = j;
}
else {
char * typeREJ = malloc(5);
sprintf(typeREJ, "rej%d", !info->sequenceNumber);
//printf("criar frame de %s \n", typeREJ);
buildFrame(info->flag, typeREJ);
transmitirFrame(info->frameSend, info->frameSendLength);
free(typeREJ);
continue;
}
}
break;
}
return 1;
}
int llread(int fd, unsigned char** buffer) {
int stuff_size;
int pack_size;
falhas = 0;
while (1) {
unsigned char *stuffed = malloc((PACK_SIZE + 4) * 2 + 2);
alarm(timeoutTime);
timeout = 0;
stuff_size = 0;
int start = 0;
int stop = 0;
while (timeout != 1 && !stop) {
int r = read(fd, &stuffed[stuff_size], 1);
if (r > 0) {
if (stuff_size != 0 && stuffed[stuff_size] == F)
stop = 1;
else if (stuff_size == 0 && stuffed[0] == F)
start = 1;
if (start)
stuff_size += r;
}
}
if (timeout == 1) {
timeout = 0;
continue;
}
falhas = 0;
alarm(0);
unsigned char* frame;
int frame_size = destuffing(stuffed, stuff_size, &frame);
if (frame_size < 0) {
//send_reject(fd);
continue;
}
pack_size = infoStateMachine(frame, frame_size, buffer);
if (pack_size < 0) {
//send_reject(fd);
continue;
}
if (pack_size >= 0) {
unsigned char* rr;
int missing;
if (ns == 0)
missing = create_control_frame(RR1, &rr);
else
missing = create_control_frame(RR0, &rr);
int num = 0;
while (missing > 0) {
num = write(fd, rr, missing);
rr += num;
missing -= num;
}
break;
}
}
if (ns == 0)
ns = 1;
else
ns = 0;
if (falhas < numRetransmissoes)
return pack_size;
return -1;
}
