After you have set up the Wi-Fi access point on the Raspberry PI, you may also need a Captive Portal. The Captive Portal will be shown to STA's directly after they connected to your Wi-Fi, like in Hotels, Airports, public Hotspots, etc. The problem with this is that people can copy such Captive Portals and gather sensible information (e.g. login credentials).
The aim of this tutorial is to set up a simple (open) captive portal in few minutes and to show how you can modify the specific web pages.
You should already have read (and successful carried out) the following tutorials.
Install (or ensure they are installed) following packages.
# update system (optional)
$ sudo apt update -y && sudo apt upgrade -y
# install optional packages (optional)
$ sudo apt install -y vim tree
# install needed packages
$ sudo apt install -y git build-essential libmicrohttpd-dev# change into home directory
$ cd ~
# clone Github repository
$ git clone https://github.com/nodogsplash/nodogsplash.git
# change into cloned directory
$ cd nodogsplash/
# run make
$ make
# run make and install
$ sudo make installNote: read this documentation pages for more information.
# backup default nodogsplash configuration (optional)
$ sudo mv /etc/nodogsplash/nodogsplash.conf /etc/nodogsplash/nodogsplash.conf.bak
# modify dhcpcd configuration
$ sudo vim /etc/nodogsplash/nodogsplash.confUncomment and/or add the following lines in /etc/nodogsplash/nodogsplash.conf configuration file.
# Gateway interface
GatewayInterface wlan1
# Gateway name
GatewayInterface WuTangLan
# Gateway address
GatewayAddress 192.168.0.1
# Status page
StatusPage status.html
# Spalsh page
SplashPage splash.html
# Redirect url
RedirectURL https://google.com
# Max clients
MaxClients 100
Now you modify /etc/nodogsplash/htdocs/splash.html and /etc/nodogsplash/htdocs/status.html. If you don't like to provide your own content now, you can skip this step.
$ sudo tree /etc/nodogsplash/htdocs/
├── images
│ └── splash.jpg
├── splash.css
├── splash.html
└── status.html
# backup default nodogsplash splash.html (optional)
$ sudo mv /etc/nodogsplash/htdocs/splash.html /etc/nodogsplash/htdocs/splash.html.bak
# backup default nodogsplash status.html (optional)
$ sudo mv /etc/nodogsplash/htdocs/status.html /etc/nodogsplash/htdocs/status.html.bakThe example content for splash.html.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>$gatewayname</title>
</head>
<body>
<div>
<h1>Welcome to $gatewayname</h1>
<p><a href="$authtarget" target="_self">ENTER NOW</a></p>
</div>
</body>
</html>The example content for status.html.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>$gatewayname</title>
</head>
<body>
<div>
<p>You are already logged in and have access to the Internet.</p>
</div>
</body>
</html># copy service file into /lib/systemd/system
$ sudo cp ~/nodogsplash/debian/nodogsplash.service /lib/systemd/system/
# start nodogsplash service
$ sudo systemctl start nodogsplash
# enable nodogsplash service
$ sudo systemctl enable nodogsplash
# check status of nodogsplash service (optional)
$ sudo systemctl status nodogsplashIf something don't work, following commands will help. Also check your configuration files again! Sometimes errors creep into the IP addresses.
# show status of service
$ systemctl status nodogsplash
$ ps ax | grep nodogsplashmacOS
Sometimes macOS does not open the Captive Portal (for example if you have modified the default DNS settings), you can try http://captive.apple.com or http://192.168.0.1.
Note: like the first in first part, this tutorial did not go into more depth on security (e.g. os hardening, firewall, etc.)!