What I'd like to do, for an event, is use a Mac Mini to share a Internet connection via WiFi. However, I'd like to put up a splash page to the joining device's browser. It would display the free WiFi is sponsored by blah, terms and conditions are blah, etc.
How would I force that redirect on joining? I know plenty of companies do it but I can't find a solution that either isn't a Hotel level enterprise product or a hack to a existing router. Any ideas?