This is an attempt to create a WebGui for blocking and unblocking network traffic via intercepting DNS request using the linux daemon dnsmasq.
A demo of the DNS Blocker WebGui at: http://www.findnear.info/dnsgui/viewlog.php
A blog about the DNS Blocker WebGui at: http://jacobsalmela.com/a-web-interface-for-the-ad-blocking-pi-hole/
Some Related Pi-Hole Project links:
- Issue 1 and 2
- Write a how to guide for the follwoing:
- Installing dnsmasq, lighttpd, php-cgi and (sqlite3 optional)
- Setting up the webgui.
- [DONE] Createing a small (5/10MB) ramdrive for Raspberry PI users for dnsmasq continuous log.
- [DONE] Config dnsmasq to log query.
- [DONE] Setting up cron job to run dnsgui/inc/update-db-dnslog.php to update the dnslog.db every 30 min.
- [DONE] Add a sudoer entry for www-data user for "(usr/sbin?)/dnsblocker-phpsudotask.sh" in
HOW TO GUIDE:
Ramdisk and dnsmasq log file
dnsmasq daemon need to be configured so that it logs all queries. This can be done by editing the /etc/dnsmasq.conf file. the follwing two line needed to be added.
It is possible to create a small ramdrive (about 5 or 10MB) and configure the dnsmasq daemon write its logfile into the ramdrive using the "log-facility=" option in /etc/dnsmasq.conf. A ramdrive can be created by using the command:
"mount -t tmpfs -o size=10M tmpfs /mnt/ramdisk"
Cron job and Updating the dnsgui/inc/dnslog.db database from dnsmasq log file
I have wrote a php script (/dnsgui/inc/update-db-dnslog.php) that reads and does some analysis and enter data into the dnslog table of the database. This task can be automated by creating a cron job. crontab can be edited by typing "crontab -e" in terminal window.
*/30 * * * * /usr/sbin/update-dns-db.sh
Adding the above line at the bottom of the crontab file will run the script (update-dns-db.sh) every 30 minutes. Writting the follwoing lines in the /usr/sbin/update-dns-db.sh file will cause the dnslog.db to be updated every 30 minues. update-dns-db.sh will also empty the dnsmasq logfile so that it does not keep on growing. This script will also recode the output message from the update-db-dnslog.php into the logfile which can be used for future troubleshooting.
#!/bin/bash /usr/bin/php-cgi /var/www/dnsgui/inc/update-db-dnslog.php
Once the data is in the dnslog.db, viewlog.php and index.php act as an interactive GUI to view and manipulate the dnslog.db.
dnslog.db has the following 2 tables:
+-------------------------------+ | dnslog table | +-------------------------------+ | hit | url | op | t1 | t2 | ip | +-------------------------------+
+-----------------+ | blocklist table | +-----------------+ | url | op | +-----------------+
"dnslog" table stores all the processed loged from dnsmasq logfile. "blocklist" table stores list of all the urls that dnsmasq blocks using the ".conf" files in "/etc/dnsmasq.d/". The ".conf" file in "/etc/dnsmasq.d/" are generated based on this table.
hit = accumulated hit count url = dns query url in dnslog table. address to be blocked in blocklist table. op = blocked option (0=unblocked, 1=blocked by auto-list, 2=blocked by custom list) t1 = first time and date the dns url query was requested. t2 = last time and date the dns url query was requested. ip = ip address of the last holt requested dns query about the given url
About the "dnsgui\" directory and setting up webgui
├── dnsgui │ ├── css │ │ └── dnsblocker-webgui-style-01.css │ ├── img │ │ ├── block-icon-color1.png │ │ ├── checkbox-color1.gif │ │ ├── circle-green1.png │ │ ├── circle-red1.png │ │ ├── search-icon-color2.png │ │ └── unblock-icon-color1.png │ ├── inc │ │ ├── blocklist-conf-inc.php │ │ ├── common-html-inc.php │ │ ├── db │ │ │ └── dnslog.db │ │ ├── global-var-inc.php │ │ ├── update-db-dnslog-inc.php │ │ └── update-db-dnslog.php │ ├── index.php │ ├── modlist.php │ ├── test.php │ ├── viewlist.php │ └── viewlog.php ├── LICENSE ├── project-files.txt └── README.md
The directory "dnsgui/" needs to be put inside your webservers "document-root" directory. In my case, on a default lighttpd install it was '/var/www'. You can find your document-root directory true location in /etc/lighttpd.d/lighttpd.conf file.
About auto-list and custom-list:
According to the /etc/dnsmasq.d/README file, dnsmasq by default will read all files in '/etc/dnsmasq.d/' directory. So it is possible to create just one single file with all the list of blocked domain addresses. But this webgui follows the original pi-hole convention and separates all the blocked domain addresses into two distinct list (auto-list and custom-list). According to the pi-hole convention, all the blocked domain addresses that are acquired as a part of automated script from web sources are stored in the adblock.conf (aka auto-list, Op=1 in webgui). All the blocked domain addresses added by the user manually goes into the adblock-custom.conf (aka custom-list. Op=2 in webgui). When webgui regenerates the '.conf' files, it appropriatly puts all the automically acquired blocked addresses into auto-list (can be any filename discribe in dnsgui/inc/global-var-inc.php) and puts all the manually blocked addresses into custom-list (can also be any filename discribe in dnsgui/inc/global-var-inc.php).
About sudoer and fire permissions requirement for dnsgui:
on a default lighttpt and php-cgi install dnsblocker-webgui runs as 'www-data' user under linux. In order for the webgui to carry out certain operation 'www-data' user will require read and write permissions to certain files. Without sufficient permissions those operations will fail.
- For almost all operation 'www-data' require both read and write permissions to “dnsgui/inc/dnslog.db” file.
- In order to regenerating '.conf' files in the '/etc/dnsmasq.d' directory, 'www-data' user needs read and write permissions to auto-list and custom-list '.conf' files.
- In order to empty the dnsmasq log file, 'www-data' user need read and write permissions to that file.
www-data ALL=(ALL) NOPASSWD: /home/pi/dnsblocker-phpsudotask.sh