Extending networking/socket programming functionality of a qml project

qcoderpro

@SGaist
What do you mean by copying part of the code I wrote above? I didn't get it. Do you mean those three lines of code are sufficient to make an Http request? Then how about the string!? :|

@JonB
You mean this way?

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

connect(manager, &QNetworkAccessManager::finished, [] {
        QNetworkReply* reply = nullptr;
        if(reply->error())
            qInfo() << "ERROR!: " + reply->errorString();
        else
            qInfo() << "Reply got back with no error!";

        reply->deleteLater();
    });

manager->put(request,data);

I'm confused! :(
Furthermore the put function uploads the contents of data to the destination request, while both my data and destination are packed into that data!

JonB

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

@JonB
You mean this way?

Yes, I think it's preferable to attach the slot to manager's signal before you call manager->put(). Though @VRonin pointed out it doesn't actually matter in this case, but it's good style anyway.

VRonin

Since I've been summoned... how is this not a segfault?

QNetworkReply* reply = nullptr;
if(reply->error())

What you should do is connect the QNetworkReply, not the QNetworkAccessManager.

// the initialisation of these 2 looks wrong but I'll ignore it for now
QNetworkAccessManager* manager = new QNetworkAccessManager(this);
const QNetworkRequest request;
const QByteArray data {"https://coderdevqt@gmail.com:passwordexample@dynupdate.no-ip.com/nic/update?hostname=coderdev.ddns.net"};
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);

qcoderpro

@VRonin

That's better, thanks. The project doesn't itself terminate and works but I get this error!

I've used the exact same string as yours, of course with my real info.

VRonin

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

I've used the exact same string as yours, of course with my real info.

Yeah, I expected something like that, hence my comment:

the initialisation of these 2 looks wrong but I'll ignore it for now

Your request has no url...
I have no idea how the server you are trying to connect to works so it's hard to tell you exactly what to do. Did you manage to do what you want with the server with another tool (like curl, or a browser-based rest client)?

SGaist

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

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

This is not the payload, it's the full query. The API has no payload.

Please read again the documentation.

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.