Extending networking/socket programming functionality of a qml project

qcoderpro

@SGaist @VRonin
I'm rather confused.
Do you mean to split the string into two parts, one for data, and the other for request like this?

const QByteArray data {"https://coderdevqt@gmail.com:passwordexample"};
const QNetworkRequest request;
request.rawHeader("@dynupdate.no-ip.com/nic/update?hostname=coderdev.ddns.net");

QNetworkAccessManager* manager = new QNetworkAccessManager(this);
QNetworkReply* reply = manager->put(request,data);

connect(reply,&QNetworkReply::finished,this,[reply](){
    if(reply->error())
        qInfo() << "ERROR!: " + reply->errorString();
    else
        qInfo() << "Reply got back with no error!";
});
connect(reply,&QNetworkReply::finished,reply,&QNetworkReply::deleteLater);

The result shows the same error! :|

SGaist

Here is an example that shows how to do it in a simple fashion with the various elements of the query separated (replace what is found between <> with adequate values):

QByteArray auth = "<username>:<password>";
QByteArray authHeaderData = "Basic " + auth.toBase64();

QUrl requestUrl("https://dynupdate.no-ip.com/nic/update");
requestUrl.setQuery("hostname=<your-host-name>&myip=<your-ip-address>");

QNetworkRequest request(requestUrl);
request.setRawHeader("Authorization", authHeaderData);

QNetworkReply * reply = qnam.get(request);

qcoderpro

@SGaist
The part myip is optional because the server's IP address connecting to their system will be used. So I use the version below, if you agree:

    QByteArray auth = "myEmail:myPass";
    QByteArray authHeaderData = "Basic " + auth.toBase64();
    
    QUrl requestUrl("https://dynupdate.no-ip.com/nic/update");
    requestUrl.setQuery("hostname=coderdev.ddns.net");
    
    QNetworkRequest request(requestUrl);
    request.setRawHeader("Authorization", authHeaderData);
    
    QNetworkReply * reply = qnam.get(request);

Two more questions:
1- We've dropped the @ sign existing in the first string. Doesn't matter?
2- What's qnam, please?

SGaist

Sure it does matter, that's the authentication part. Re-read the code.
a QNetwornAccessManager object.

qcoderpro

@SGaist
I meant the @ in the string:
"...//coderdevqt@gmail.com:passwordexample@dynupdate.no-ip.com/nic/update?hostname=coderdev.ddns.net"

The message "Reply got back with no error!" is printed for this:

QByteArray auth = "myEmail:myPass";
QByteArray authHeaderData = "Basic " + auth.toBase64();

QUrl requestUrl("https://dynupdate.no-ip.com/nic/update");
requestUrl.setQuery("hostname=coderdev.ddns.net");

QNetworkRequest request(requestUrl);
request.setRawHeader("Authorization", authHeaderData);

QNetworkAccessManager* qnam = new QNetworkAccessManager(this);
QNetworkReply * reply = qnam->get(request);
 if(reply->error())
    qInfo() << "ERROR!: " + reply->errorString();
else
    qInfo() << "Reply got back with no error!";

So probably the record has been updated successfully.

For the client app I used the code below but the messages don't appear to be exchanged between the apps!

   QHostInfo info = QHostInfo::fromName("coderdev.ddns.net");
  //  If updating over HTTPS, our system listens on Port 443
    sendAddress(info.addresses().front(), 443);

// ...
void Client::sendAddress(QHostAddress ip, unsigned int port)
{
    tcpSocket->abort();
    tcpSocket->connectToHost(ip, port);
}

SGaist

I know that you are talking about the "@". As I wrote, it's about authentication. There are several ways to do it.

As for the client side, did you connect the error signals of your socket ?
Does your server really answer on port 443 ?

qcoderpro

@SGaist

I get this message for this error:

 case QAbstractSocket::ConnectionRefusedError:
        qInfo() << "The connection was refused by the peer. "
                   "Make sure the server is running, "
                   "and check that the host name and port "
                   "settings are correct.";

As for the port number, they say in Sending an Update in their website: If updating over HTTPS, our system listens on Port 443 It is not necessary to open any incoming ports for updating.

Of course both apps are running on the same machine.

qcoderpro

Sorry, there was a problem with my connection. Now that I runt the two apps (on my Windows machine), they both run successfully (with no errors) but messages won't be sent/received. That is, whatever I write and click on the Send button, nothing appears on the other side! :(

When sending messages on the server app, the error below appears on the Application Output window:
"QIODevice::write (QTcpSocket): device not open"

SGaist

You are mixing noip API server and yours. They are not the same and the port you use for your application is unrelated to the one you use to update your account.

As for your socket issue, I do not see any error checking done in your code so you do not even know whether your connection was successful.

qcoderpro

@SGaist

You are mixing noip API server and yours. They are not the same and the port you use for your application is unrelated to the one you use to update your account.

Sounds reasonable. So what port number should I use for my client app to be able to connect to the server app, please? The sever sends its IP by updating the record, but how about a port? How to find a port for the connection?

jsulm

@qcoderpro said in Extending networking/socket programming functionality of a qml project:

So what port number should I use for my client app to be able to connect to the server app, please?

The port your server is listening for connections.
It is your server, so you should know what server you use.

qcoderpro

@jsulm
The server may be run by someone in another country, so how the client should know the port number!? :|
Furthermore, you said: port number can be fixed (like 8080 for HTTP).

For the connection both IP and port are needed, As far as I'm concerned. No-ip works out the problem with IP. But how about the port number? :(

jsulm

@qcoderpro Question: do you have to use a fix port number or not? Port can be fixed like it is for many protocols.

qcoderpro

@jsulm
I don't know since I'm new to networking. Actually I chose Qt to learn socket programming. When running the apps on the same machine, the client needs both IP and port to connect to the server. The server publishes both, say, this for the port: QString::number(tcpServer->serverPort()), and since I can see them, I enter IP and port in client's fields to connect to server.
Now that the apps are going to work remotely, for example, each running by a person in a different location (not on the same machine), the IP problem is going to be fixed using noip. But the port problem remains. So I assume there're two ways to work it out, 1- use a fixed port or 2- use any port the server offers but this way we need to somehow deliver that number to client to give it the ability to establish the connection.
Now you choose what to choose please.

SGaist

That's your application so that decision is yours.

As you were already explained, peer to peer communication has different constraints than the use of a central server.

qcoderpro

@SGaist
Since I've not been dealt with projects like that, I'm seeking the easiest way. An easy free service like No-ip. I wish it could solve the issue with the port as well. :|
What do you suggest, please?

jsulm

@qcoderpro said in Extending networking/socket programming functionality of a qml project:

What do you suggest, please?

I suggest to use a fixed port number...

qcoderpro

@jsulm
Good. Could you also guide me how to do that? I mean if there's any reference or Docs page to help me learn how to do that I will be appreciative.

SGaist

https://en.m.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers

qcoderpro

@SGaist
Sorry for the delay. I was very busy. If you think it's better, I'm going to create a new thread for the problem.

I checked the page for the ports numbers and tested a couple of them which are related to messaging based on TCP.

My server.cpp has:

Server::Server(QObject *parent)
    : QObject{parent}
    , tcpSocket(new QTcpSocket(this))
    , tcpServer(new QTcpServer(this))
{
    initServer();
}

QString Server::initServer() {

    tcpServer = new QTcpServer(this);
    if(!tcpServer->listen())
        return "Server Unable to start the server: " +
                tcpServer->errorString();

    connect(tcpServer, &QTcpServer::newConnection, this, &Server::onNewConnection);

    QByteArray auth = "myEmail@gmail.com:myPass";
    QByteArray authHeaderData = "Basic " + auth.toBase64();

    QUrl requestUrl("https://dynupdate.no-ip.com/nic/update");
    requestUrl.setQuery("hostname=coderdev.ddns.net");

    QNetworkRequest request(requestUrl);
    request.setRawHeader("Authorization", authHeaderData);

    QNetworkAccessManager* qnam = new QNetworkAccessManager(this);
    QNetworkReply * reply = qnam->get(request);

    if(reply->error())
        qInfo() << "ERROR!: " + reply->errorString();
    else
        qInfo() << "Reply got back with no error!";
}

void Server::onNewConnection() {

    qInfo() << "New connection arrived!";

    tcpSocket = tcpServer->nextPendingConnection();
    connect(tcpSocket, &QAbstractSocket::errorOccurred, this, &Server::displayError);
    inOut.setDevice(tcpSocket);
    inOut.setVersion(QDataStream::QDataStream::Qt_5_10);
    connect(tcpSocket, &QAbstractSocket::readyRead, this, &Server::writeMessage);
}
...

First ran this app and got the message: Reply got back with no error!

client.cpp contains:

Client::Client(QObject *parent)
    : QObject{parent}
    , tcpSocket(new QTcpSocket(this))
{
    inOut.setDevice(tcpSocket);
    inOut.setVersion(QDataStream::Qt_5_10);
    connect(tcpSocket, &QAbstractSocket::readyRead, this, &Client::writeMessage);
    connect(tcpSocket, &QAbstractSocket::errorOccurred, this, &Client::displayError);

    QHostInfo info = QHostInfo::fromName("coderdev.ddns.net");
    sendAddress(info.addresses().front(), 4662);

    /*   18	Message Send Protocol[19][20]
         157	Assigned  KNET/VM Command/Message Protocol
         218	Message posting protocol (MPP)
         993	Internet Message Access Protocol over TLS/SSL (IMAPS)[11]
         2123	GTP control messages (GTP-C)
         2152	GTP user data messages (GTP-U)
         2775	Short Message Peer-to-Peer (SMPP)[citation need
         4662	OrbitNet Message Service
    */
}

void Client::sendAddress(QHostAddress ip, unsigned int port)
{
    tcpSocket->abort();
    tcpSocket->connectToHost(ip, port);
}
...

After running the server (and hoping that the record on noip has been updated correctly), ran the client and tested all ports above!
Yet no new connection nor an error from the displayError slot.
But Qt Creator gives the error: Cannot retrieve debugging output. for all of the ports!

Where is the problem, please? :(