Based on hostapd, I am building a captive portal.
- My Linux Machine provides Wifi access.
- iPad's and Android clients-tablets connect to this Wifi.
Generally, any client OS checks if a URL is reachable; if not: client OS states it is captive, and displays a popup browser window. The popup is used for login, presentation or else.
I'd like to display such a popup to present my machine's service, but I don't get it. I've avoided the net forward though. All connections are redirected in the machine localhost website.
Why don't I get such a popup? How to get it? How/Where should I implement it on my localhost?
When the popup happens, how is its content is defined? For instance, a restaurant captive portal asks for your secret number on your note; where is this page is stored? How does the OS know the URL to display in the popup?