void Protocol::setCarrier(const std::string& carrierNameBase)
{
// Set up the carrier for this connection. The carrier
// has all the protocol-specific behavior.
std::string carrierName = carrierNameBase;
if (carrierNameBase == "")
carrierName = "tcp";
Route route = getRoute();
route.setCarrierName(carrierName);
setRoute(route);
if (delegate == nullptr) {
delegate = Carriers::chooseCarrier(carrierName);
if (delegate != nullptr) {
if (delegate->modifiesIncomingData()) {
if (active) {
fprintf(stderr, "Carrier \"%s\" cannot be used this way, try \"tcp+recv.%s\" instead.\n", carrierName.c_str(), carrierName.c_str());
}
close();
return;
}
// Configure the carrier.
if (!delegate->configure(*this)) {
fprintf(stderr, "Carrier \"%s\" could not be configured.\n", carrierName.c_str());
close();
return;
}
delegate->prepareSend(*this);
}
}
}
void Protocol::setRoute(const Route& route)
{
Route r = route;
// We reorganize the route to reduce variation in naming.
// If there are qualifiers in the source port name, propagate
// those qualifiers to the carrier.
std::string from = r.getFromName();
std::string carrier = r.getCarrierName();
if (from.find(' ') != std::string::npos) {
Bottle b(from);
if (b.size() > 1) {
r.setFromName(b.get(0).toString());
for (size_t i = 1; i < b.size(); i++) {
Value& v = b.get(i);
Bottle* lst = v.asList();
if (lst != nullptr) {
carrier.append("+").append(lst->get(0).toString()).append(".").append(lst->get(1).toString());
} else {
carrier.append("+").append(v.toString());
}
}
r.setCarrierName(carrier);
}
}
// Record canonicalized route.
this->route = r;
// Check if we have a receiver modifier.
if (!recv_delegate) {
Bottle b(getSenderSpecifier());
if (b.check("recv")) {
need_recv_delegate = true;
}
}
// Check if we have a sender modifier.
if (!send_delegate) {
Bottle b(getSenderSpecifier());
if (b.check("send")) {
need_send_delegate = true;
}
}
}
bool Protocol::expectProtocolSpecifier()
{
// Historically YARP has used the first 8 bytes of
// every connection as a way to identify it. This
// assumption is showing its age, and should really
// be generalized.
char buf[8];
yarp::os::Bytes header((char*)&buf[0], sizeof(buf));
yarp::conf::ssize_t len = is().readFull(header);
if (len == -1) {
YARP_DEBUG(log, "no connection");
return false;
}
if ((size_t)len != header.length()) {
YARP_DEBUG(log, "data stream died");
return false;
}
bool already = false;
if (delegate != nullptr) {
if (delegate->checkHeader(header)) {
already = true;
}
}
if (!already) {
delegate = Carriers::chooseCarrier(header);
if (delegate == nullptr) {
// Carrier not found; send a human-readable message.
std::string msg = "* Error. Protocol not found.\r\n* Hello. You appear to be trying to communicate with a YARP Port.\r\n* The first 8 bytes sent to a YARP Port are critical for identifying the\r\n* protocol you wish to speak.\r\n* The first 8 bytes you sent were not associated with any particular protocol.\r\n* If you are a human, try typing \"CONNECT foo\" followed by a <RETURN>.\r\n* The 8 bytes \"CONNECT \" correspond to a simple text-mode protocol.\r\n* Goodbye.\r\n";
yarp::os::Bytes b((char*)msg.c_str(), msg.length());
os().write(b);
os().flush();
}
}
if (delegate == nullptr) {
YARP_DEBUG(log, "unrecognized protocol");
return false;
}
Route r = getRoute();
r.setCarrierName(delegate->getName());
setRoute(r);
delegate->setParameters(header);
return true;
}
