Intro

Due to our strict constrains with regards to captive portals (low-memory, no-login needed, auto-update of content) we decided to make our own. The software we build WLPortal is based around 5 components:

1. pf or ipfw firewall rules in the FreeBSD kernel.
2. thttpd instance serving the captive portal CGI.
3. The CGI script itself.
4. The template files for making the entrance pretty.
5. crontab entry to cleanup stale entries.

Work flow

1. The user gets deflected to the Captive Portal by the firewall if he/she tries to reach an external website.
2. The user reads the welcome pages and clicks OK.
3. The MAC/IP of the user's device gets whitelisted in the firewalll.
4. The user gets redirected to the specified website (​http://wirelessleiden.nl by default).
5. The crontab entry deletes the user if he/she has been idle too long.

Template configurations

Important: this only holds true for nodes build in the iris-releng-9.0-ileiden branch, build after r10249 | rick | 2012-03-19 19:06:36 +0100 (Mon, 19 Mar 2012)

Warning: Make sure to only alter the cosmetics of the file and not the technical structure of the forms or submit url.

You can edit the config file with: node# vim /usr/local/etc/wlportal/login.tmpl

Please do mind that this file gets lost after a reboot. If you like to store the edited file in a persistent place, make sure to place it at the configuration store: node# mount -uwo noatime /cfg node# cp /usr/local/etc/wlportal/login.tmpl /cfg/local/wlportal/login.tmpl node# umount /cfg

Configuration File

You can use the configuration file file:/usr/local/etc/wlportal/config.yaml to provide overwrites to the base configuration entries defined in the script. This allows you to alter the default redirect website and white-listing of specific hosts.

File Hierarchy

• file:/usr/local/www/wlportal/index.cgi - The Main worker.
• file:/etc/ipfw.sh or file:/etc/pf.conf - The Base Firewall Redirect Rules.
• file:/usr/local/etc/wlportal/login.tmpl - Active Template.
• file:/usr/local/etc/wlportal/config.yaml - Active Configuration.
• file:/usr/local/etc/thttpd.conf - Active thttpd Configuration.
• file:/etc/crontab - crontab(4) recycle calls.
• file:/etc/rc.conf.local - Startup configuration for the local daemons.