Android Question Captive Portal

[Blueforcer]

Hello everyone,

I'm currently working on a project using B4A where I've set up a mini web server as well as the function to start a wifi AP.
My goal is to automatically prompt users to open a specific webpage as soon as they connect to the WiFi hotspot provided by the device.

I understand that this typically involves creating a sort of captive portal, where the device intercepts network requests and directs them to a predetermined page until the user completes a specific action (like logging in or accepting terms). However, I'm unsure how to handle the network configurations and DNS settings within B4A to achieve this.

BTW: I have root access on this device.

 

[DonManfred]

Does this help?

API-Unterstützung im Captive Portal | Android Developers

developer.android.com

 

[Blueforcer]

Does this help?

API-Unterstützung im Captive Portal | Android Developers

developer.android.com

Kind of.

i managed to forward every request to my B4A webserver

 Dim s As SuShell
    s.Execute("iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 8321")
    s.Execute("iptables -A FORWARD -p udp --dport 53 -j ACCEPT")
    s.Execute("iptables -A FORWARD -p udp --sport 53 -j ACCEPT")
    s.Execute("iptables -t nat -A PREROUTING -p udp --dport 53 -j DNAT --to-destination 192.168.43.1")
    s.Execute("iptables -P FORWARD DROP")

and when a client connects to the hotspot, my webserver recognized a request from it. Unfortunally it does not open the webpage.

But if I understand your article correctly, the web server must support https. Which neither the httpServer from erel nor xHttpServer supports.

 

[DonManfred]

I guess you can not run a https server on Android because you are not able to set the Certificate for it.

What about setting up a B4J-Server?

PD: I do not own any rooted device though. I fear i can´t help any further.

 

[Blueforcer]

Https in general should not be the problem. see

HTTPS Server on Android Device Using NanoHttpd

I am trying to run an HTTPS Server on an Android device using NanoHttpd (my final goal is to run WSS server on Android). I successfully ran HTTP Server and Websocket using NanoHttpd on Android. I

stackoverflow.com

but currently we doesnt have libs wich support that.

B4J is out of the question, as it is an industrial Android HMI that is used for measuring and controlling pools.

But then the user has to enter the URL manually, which isn't too bad.

 

[DonManfred]

but currently we doesnt have libs wich support that

find a java-example. I can help in wrappercreation for it.

 

[Blueforcer]

GitHub - NanoHttpd/nanohttpd: Tiny, easily embeddable HTTP server in Java.

Tiny, easily embeddable HTTP server in Java. Contribute to NanoHttpd/nanohttpd development by creating an account on GitHub.

github.com

This one have SSL support.

Seems like other already tried but they give up

nanoHTTPD

Hi, I'm trying to port the nanoHTTPD library to B4A using SLC. SLC generates the JAR file but the message "Error parsing libraries. fi.iki.elonen.nanoHTTPD.asyncrunner already exists" appears when refreshing libraries. I already tried to hide classes, change the names, length of the package...

www.b4x.com

 

[DonManfred]

This one have SSL support.

i´ll have a look at it

they give up

Creating a wrapper needs a bit more than just Copy&Pasting code