ciao: Curb Internet Addiction by Omission

Bash command line tool for managing /etc/hosts or DNSCrypt cloaking

Usage

ciao add facebook.com        # starts blocking facebook.com network access
ciao remove facebook.com     # stop blocking facebook.com
ciao off                     # stop block *all* added domains
ciao on                      # start blocking *all* domains, again

Installation

TL;DR

Open a terminal, then

git clone https://github.com/adamtait/ciao.git
./ciao/quick_install.sh

Full Install

1. clone this repo
2. source cmd.sh from your .bashrc or .bash_profile
3. run ./setup.sh
4. update your ~/.ciao/config

Motivation

I spend too much time on my computers browsing endless news articles and social notes, and not enough time focussing on what I sat down at my computer to do (always something other than just browsing). I've tried Chrome & Firefox browser extensions, which all have their own quirks and it's too easy to change browsers to one that isn't blocking. I've tried managing my own /etc/hosts file, but inevitably I get comfortable changing it and change it too often. So, none of these focus solutions has worked particularly well for me.

I had a few priorities when I thought about building ciao.

• works on all browsers
  • I regularly switch between 3+ browsers, so I need it to be hard to circumvent
• accessible from the command line
  • I spend most of my productive time there
• easy to integrate with my existing command line setup
  • my https://github.com/adamtait/dotfiles has a lifecycle; install, then setup, then session
• easy to edit
  • accessible from the command line covered most of this, but I also wanted to have plain text interface
• easy to turn on/off
  • sometimes I do actually want to surf

This tool (really, a set of tools) works great for me. If you get into it and have any thoughts or feedback, PRs & issues are certainly welcome!

Design Decisions

duplicating /etc/hosts

I thought about just updating /etc/hosts in place, but decided that solution was prone to error. Duplicating /etc/hosts means that:

• we can maintain a backup
• we can manage a regular text file to control our blocked DNS entries

These benefits seemed worth the additional complexity of having to maintain the duplicate and syncing between them.

requiring a password for each change

Changing /etc/hosts requires changing a root owned file with limited write permissions. This means sudo.

In my mind, an effort to not required a password was a closely balanced tradeoff. It would be inconvenient to require sudo and enter your password on every change, especially if you change ciao often. On the other hand, isn't the point that you shouldn't be enabling & disabling often? Requiring a password is a barrier, possibly aiding to curbing your internet addiction.

The tie-breaker was requiring additional setup & reduced security by changing /etc/sudoers (or better, /etc/sudoers.d/) in order to remove the password requirement of sudo.

Furthermore, if you make a bunch of changes within a few seconds of each other then sudo won't ask for a password after the first success. That was the most common frustrating scenario, which sudo already makes painless.

Also considered was using sudo only once to change the ownership/permissions on /etc/hosts. Beyond the lower permissions being a possible security hole (any app could re-direct traffic from your banking website to a phishing scam site), it didn't actually work. Appending to a permissable /etc/hosts file worked but overwriting it did not. I didn't delve further to understand the source.

not using a file watcher

When I first thought of this tool, I wanted the interface to be a plain text file that I could easily edit and automatically have changes reflected in /etc/hosts. Adding this feature would require watching the file for changes, probably using a file watcher.

However, it wasn't worth the effort to get sudo to work without a tty session available (watchman runs without one).

There are other filesystem notification tools out there, and I haven't tried them but suspect they would have similar challenges.

not using a cron

Setting focus time on schedule doesn't fit my lifestyle. I work & goof-off at different hours each day. Additionally, it would require special permissions (changes to /etc/sudoers or /etc/sudoers.d) similar to a file watcher.

Overrides

Once I found out that facebook.com makes blocking their DNS entries very difficult (see overrides/facebook.com for all the domains needed), I decided to add overrides. I suspect that many other companies (like google.com or stumbleupon.com) that trying desperately to track you will have similarly long lists of DNS entries that need to be blocked.

I welcome PRs for additional global overrides.

Support for DNSCrypt

I recently learned about DNSCrypt and have found it to be an even better tool that /etc/hosts for managing DNS. It offers so much more control, but in case you're not convinced - go read this. However, it doesn't offer command line support for cloaking or blocking domain names.

Fortunately with a simple change in config, I was able to adapt CIAO to work with DNSCrypt also.