Raspberry 4 provisioning ap wifi using hostapd and dnsmasq

1. Introduction

• When power on RPI, if their is no wifi connection, the wifi AP will automatically run.( these ssid and password can be modified in ./config_ap/hostapd.conf)
  • SSID : RPIWifiConfig
  • password : 1234567890
• When connecting to AP the setup page will automatically show off (only test on iphone and Ipad and some android phone). By using this page you can configure to connect to your own AP.

2. Requisition software

• Setup wifi country code

  sudo raspi-config
  #------>5 Localisation Options
  #-------------->L4 WLAN Country
  #---------------------> AT Austria
  

• Libs and software packages

  sudo apt-get update
  sudo apt-get upgrade
  sudo apt-get install -y python3 curl git build-essential tmux nano hostapd dnsmasq
  
  # don't  let it done  auto
  # stop  current running instance
  sudo systemctl stop dnsmasq.service
  # disable restart service
  sudo systemctl disable dnsmasq.service 
  
  sudo systemctl stop hostapd
  sudo systemctl unmask hostapd
  sudo systemctl disable hostapd
  
  sudo reboot

• NodeJS v12:

  # install nvm  and nodejs
  curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.7/install.sh | bash
  
  source ~/.bashrc
  
  nvm install v20
  # The  sudo only recognize the PATH  in secure_path in file in /etc/sudoers
  # To see more details : run cmd :  
  # sudo visudo
  # alias node and npm to  /usr/bin sothat thay can be found  and run in sudo mode
  sudo ln -s "$(which node)" /usr/bin/node
  sudo ln -s "$(which node)" /usr/lib/node
  sudo ln -s "$(which npm)"  /usr/bin/npm

3. Install WIFI AP and captiveportal

cd SoftAP
sudo ./setup.sh 

After running setup you can have your own AP in next reboot. Or if you want to bring it up now to test:

sudo /usr/bin/autohotspot.sh

or

cd bin
sudo ./check_connect_then_start_soft_ap

The more details about setup, this will bring up 3 service:

• dnsmasg:
  • DHCP server for wifi AP o wlan0
  • Fake DNS server which ressolve all the DNS queries from connected device of this AP to 10.0.0.1, where the nodejs web captiveportal listen on port 10.0.0.1:80
• hostapd :
  • Once shoot start when powerup : check if no wifi connection on wlan0 then start AP ( wifi Access Point) depend on hostapd application. If having connection, don't start AP mode.
• captiveportal.service :
  • This is run nodejs express application as wificonfiguration to let user can config the SSID and password of wifi, they want to connect to.
  • This bind on all interface of RPI ( wlan0 and eth0) at port 80
  • Redirect all unhandle uri to root url "/"
  • Only support http ( https may support in future)

Boot process:

• ./bin/check_connect_then_start_soft_ap.sh : Check wifi in 90 sec, if no wifi connection then run ./bin/start_ap_fork.sh
  • Start hostapd app with config in ./config_ap/hostapd.conf
  • Wait 60 sec then start fake dns serser and dhcpserver on wlan0by running dnsmasq with config in ./config_ap/dnsmasq.conf
• Start flashpage nodejs webserver with sudo to listen all and create captive Portal the webserver src in CaptivePortal

4. Reference link

• https://www.raspberryconnect.com/projects/65-raspberrypi-hotspot-accesspoints/158-raspberry-pi-auto-wifi-hotspot-switch-direct-connection
• https://www.shellvoide.com/wifi/how-to-setup-captive-portal-login-with-rogue-ap-nginx/
• https://socifi-doc.atlassian.net/wiki/spaces/SC/pages/94371841/DNS+Fix+to+keep+Android+Splash+Page+and+the+Captive+Portal+Notification+active