Skip to content
/ airchat Public

AirChat lets you chat to nearby users by abusing the AirDrop interface on OS X.

Notifications You must be signed in to change notification settings

chendo/airchat

Folders and files

NameName
Last commit message
Last commit date

Latest commit

 

History

25 Commits
 
 
 
 

Repository files navigation

AirChat

AirChat is a zero-dependency* P2P CLI chat tool that (ab)uses the AirDrop interface to allow chatting across WiFi networks (or no WiFi network).

A RailsCamp AU 20 project.

Screenshot

Features

  • Chat to other AirChat users in proximity without being on the same network
  • Self-contained - no gems, nothing else to download/install
  • Automatically keeps AirDrop active
  • Commands: /nick, /who, /me, /quit
  • User colours tied to their IPv6 address

Requirements

  • OS X with system Ruby 2+ with working AirDrop
  • Ruby 2.0 or higher (comes with OS X)
  • tcpdump (comes with OS X)

Usage

# Get it
curl -L https://github.com/chendo/airchat/raw/master/airchat.rb > airchat.rb && chmod +x airchat.rb
# or get someone to AirDrop it to you, etc.

# AirChat requires raw access to the /dev/bpf* interface.
# Run using sudo
sudo ./airchat.rb
# OR
# Give permission to /dev/bpf*
sudo chgrp staff /dev/bpf* && sudo chmod g+rw /dev/bpf*  # These permissions will reset on reboot
./airchat.rb

How does it work?

AirChat uses the awdl0 interface to talk to other machines with AirDrop active. However, OS X restricts binding to this interface, and non-AirDrop network traffic is rejected with ICMP Port Unreachable. AirChat gets around this by using tcpdump to receive UDP data, as OS X doesn't stop you from sending packets through that interface.

AirChat broadcasts JSON-encoded messages in UDP to ff02::fb on port 1337.

Caveats/TODO

  • Messages are transmitted in plain text.
  • No direct messaging
  • One channel only (you can specify a different port by modifying the source)
  • Message delivery is not guaranteed
  • No message repeater functionality

License

MIT.

ANSI RGB magic sauce from the paint gem.

About

AirChat lets you chat to nearby users by abusing the AirDrop interface on OS X.

Topics

Resources

Stars

Watchers

Forks

Releases

No releases published

Packages

No packages published

Languages