Netfilter::Ruby

Awesome Netfilter (iptables & ebtables) management using ruby.

Installation

Add this line to your application's Gemfile:

gem 'netfilter-ruby'

And then execute:

$ bundle

Or install it yourself as:

$ gem install netfilter-ruby

Usage

require "netfilter"

firewall = Netfilter.new("example") do |eb, ip4, ip6|
  ip4.table :filter do |t|
    t.chain "INPUT" do |c|
      # dont lock yourself
      c.filter protocol: :tcp, dport: 22, jump: :accept
      # allow dhcp requests
      c.filter protocol: :udp, source: "0.0.0.0", sport: 68, destination: "255.255.255.255", dport: 67, jump: :accept

      # drop everything else
      # c.filter jump: :drop
    end

    # capture all outgoing traffic (all traffic to the interface)
    t.chain :input do |c|
      c.filter in_interface: "eth0", jump: "CUSTOM_CHAIN"
    end

    t.chain :forward do |c|
      c.filter in_interface: "eth0", jump: "CUSTOM_CHAIN"
    end
  end
end

# activate rules
# test your rules before put on production
firewall.up

# print applied rules
firewall.pp

Known bugs

• None

Notes

• #filter method symbols must match options and commands from the tool. i.e. iptables --help

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

Copyright

Copyright (c) 2012 - 2013 Netskin GmbH. Released unter the MIT license.