Captive Portal Save

Captive Portal on Rapsberry Pi

The following script will create an open wifi network and when you connect to it, it will automatically open the browser. Make sure you don't have the internet on your device you are connecting it from. This is originally designed to only provide local website from the RPI.

• Tested on, without updating the system first, 2019-09-26-raspbian-buster-lite.zip.
• Due to updating php this might not work on previous versions of Rasbian.

Instructions

Flash microsd card with etcher

Put an empty file called ssh with no extension onto the boot partition, this will enable ssh at first boot. No need for screen and keyboard.

Connect Pi to the ethernet network and boot.

Connect to the SSH and run below command. You can get the IP address from IP scanner.

sudo -i

curl -H 'Cache-Control: no-cache' -sSL https://raw.githubusercontent.com/tretos53/Captive-Portal/master/captiveportal.sh | sudo bash $0

If you want to specify SSID during installation run below command. If SSID is not specified CaptivePortal01 will be used.

curl -H 'Cache-Control: no-cache' -sSL https://raw.githubusercontent.com/tretos53/Captive-Portal/master/captiveportal.sh | sudo bash $0 SSID_OF_YOUR_CHOICE

To Do

Automatically set the location as new RPI hardware requires that before enabling wifi

Add a time limit for each client. Disconnect client after 10minutes.

Disable ssh access on wifi interface

Change the default Website

Test popup on other devices. Already works on Samsung S4, S7, S9, IPhone X and Blackberry

Add wifi name to be configured from the command line

Known Issues

Huawei P40 (CDY-NX9A) is still having issues.

Popup Logic

Below sites needs to be resolvable to public IPs connectivitycheck.gstatic.com www.gstatic.com www.apple.com captive.apple.com clients3.google.com

Those IPs needs to be NATed to the pi so basically NAT everything from WiFi to the RPI

Each device got it's own checks (to be updated)

Troubleshooting

Install and capture traffic using tcpdump -i wlan0 -w filename.pcap

Check nginx logs

Other

Find out which MAC addresses connected to the portal by finding all MAC addresses from the logs. Meantime solution untill I specify proper logs.

# Go to /var/logs/
cd /var/logs/

# Find all gz files and extract them
find . -name '*.gz' -execdir gunzip '{}' \;

# Find MAC addresses in all files and dont show duplicates and other stuff
grep -hoiIs '[0-9A-F]\{2\}\(:[0-9A-F]\{2\}\)\{5\}' * | sort -u


NGINX logs
# Go to /var/logs/
cd /var/logs/nginx/

# Find all unique IP addresses that connected to the website. This will show 192...
grep -hoiIs -E '([0-9]{1,3}[\.]){3}[0-9]{1,3}' * | sort -u

# Find all unique IP addresses that connected to the website. This will show more details, like what (kind of) device connected.
grep -E '([0-9]{1,3}[\.]){3}[0-9]{1,3}' * | sort -u```