Can we do IP scanning using QT

ManiRon

@jsulm I want to find the server without knowing its ip and connect with it and i want it in TCP

jsulm

@ManiRon Well, you can try to connect to all valid IP addresses in your network (subnet mask defines valid IPs), but that can take time.

ManiRon

@jsulm Ya i tried it and it takes time , thats why i am looking for an alternative

jsulm

@ManiRon Alternative is service discovery (or UDP broadcast, after broadcast you can do TCP as usual)...

ManiRon

@jsulm said in Can we do IP scanning using QT:

But for UDP broadcast i might have to implement some coding on my server side , which i might not be able to do . whether we can use UDP broadcast without modifying the server side

jsulm

@ManiRon Can't you give your server a DNS name? And then simply connect to that name instead of an IP?

ManiRon

@jsulm I have to check this way , will there be any samples available ?

kuzulis

You can try to use the nmap utility or its library to do a network scanning.

ManiRon

@kuzulis it is a little tough to understand and the flow of the code is also tough to understand, Thats why looking for an alternate way

ManiRon

@kuzulis i am not having clarity on how to use its library file with my application

jsulm

@ManiRon Pass an URL to connectToHost instead of IP

ManiRon

@jsulm said in Can we do IP scanning using QT:

connectToHost

I passed an URL but the client is not connecting to the server,

client side :

QTcpSocket *tcpSocket;
tcpSocket->connectToHost("www.test.com", 6547);

server side :

 QTcpServer *tcpServer;
 tcpServer->listen(QHostAddress::Any, 6547)

closx

@ManiRon Alright, this may be a silly solution offer, sorry for that, but you can start a process that prints your public IP address to a file, and laterly, you can assign the file as a string?

QProcess process;
process.start("curl ifconfig.me > ipaddress");
//Saves the public IP address as the file "ipaddress"
//You may delete the file with another process if you want.
QString fname="ipaddress";
QFile file(fname);
QString ip;
if (file.open(QIODevice::ReadOnly | QIODevice::Text)){
   QTextStream stream(&file);
   while (!stream.atEnd()){
            ip = stream.readLine();
    }
}
file.close();

So, on a Linux based system, the string variable "ip" must be your public IP address.

jsulm

@ManiRon said in Can we do IP scanning using QT:

www.test.com

is this the host name of your server?

jsulm

@closx He needs the IP of his server which not necessarily runs on same machine...

closx

@jsulm said in Can we do IP scanning using QT:

@closx He needs the IP of his server which not necessarily runs on same machine...

Then we can replace the code with

QProcess process;
process.start("dig +short test.com > ipaddress");
QString fname="ipaddress";
QFile file(fname);
QString ip;
if (file.open(QIODevice::ReadOnly | QIODevice::Text)){
   QTextStream stream(&file);
   while (!stream.atEnd()){
            ip = stream.readLine();
    }
}
file.close();

Didn't I still get the main problem? Am I retarded? lmao

jsulm

@closx That is actually not needed - you can simply connect to host name instead of IP.

ManiRon

This post is deleted!

ManiRon

@jsulm how to set the host name of server ? can you provide me an example ?

jsulm

@ManiRon Read the manual of your server or OS.
For Ubuntu Linux for example see https://www.cyberciti.biz/faq/ubuntu-change-hostname-command/