hda-change-network

#!/usr/bin/env ruby
#
# Amahi Home Server
# Copyright (C) 2007-2013 Amahi
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License v3
# (29 June 2007), as published in the COPYING file.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# file COPYING for more details.
#
# You should have received a copy of the GNU General Public
# License along with this program; if not, write to the Amahi
# team at http://www.amahi.org/ under "Contact Us."

require 'dbus'
require 'ipaddr'

def usage(error=nil)

	puts "error: #{error}" if error
	puts "usage: hda-change-network HDA-IP GW-IP DNS1-IP DNS2-IP"
	exit(-1)
end

def ip2int(ip_addr)
	IPAddr.new(ip_addr).hton.unpack('L').first
end

def rand_hex(l)
	"%0#{l}x" % rand(1 << l*4)
end

def rand_uuid
	[8,4,4,4,12].map {|n| rand_hex(n)}.join('-')
end

# select an ethernet connection - returns a connection object or nil
def select_connection(network_manager, connections)
	connections.each do |conn|
		conn_object = network_manager.object(conn)
		conn_object.introspect
		settings = conn_object["org.freedesktop.NetworkManager.Settings.Connection"].GetSettings
		conn_settings = settings.first['connection']
		if conn_settings['type'] == "802-3-ethernet"
			#puts "Using first ethernet connection \"#{conn_settings['id']}\"."
			return conn_object
		else
			#puts "Ignoring non-ethernet connection \"#{conn_settings['id']}\"."
		end
	end
	nil
end

def setup_network_manager(ip, gw, dns1, dns2)

	s_ip4 = {
	  "addresses"=> ["aau", [[ip2int(ip), 24, ip2int(gw)]]],
	  "method"=>["s", "manual"],
	  "dns"=> ["au", [ip2int(dns1), ip2int(dns2)]]
	}

	con = { "ipv4" => s_ip4 }

	system_bus = DBus::SystemBus.instance
	nm_service = system_bus.service("org.freedesktop.NetworkManager")
	settings = nm_service.object("/org/freedesktop/NetworkManager/Settings")
	settings.introspect
	settings_iface = settings["org.freedesktop.NetworkManager.Settings"]
	connections = settings_iface.ListConnections.first
	ethernet = select_connection(nm_service, connections)
	if ethernet
		s = ethernet["org.freedesktop.NetworkManager.Settings.Connection"].GetSettings
		new_settings = s[0].merge(con)
		# FIXME we're not sure why this needs to be done now to avoid dbus exceptions
		new_settings["connection"].delete 'permissions'
		new_settings["connection"].delete 'secondaries'
		new_settings["connection"].delete 'mac-address'
		new_settings.delete "802-3-ethernet"
		new_settings.delete "ipv6"
		ethernet["org.freedesktop.NetworkManager.Settings.Connection"].Update(new_settings)
	else
		# if we have not found an ethernet connection configured, create one
		con["connection"] = {
			"type" => "802-3-ethernet",
			"uuid"=> rand_uuid,
			"id" => "Amahi Network"
		}
		con["802-3-ethernet"] = {}
		settings_iface.AddConnection(con)
	end
end

def main
	usage unless ARGV.size == 4

	args = ARGV.map{ |a| a.strip }
	ARGV.each do |addr|
		usage("arguments must be IP addresses") unless addr =~ /^(?:[0-9]{1,3}\.){3}[0-9]{1,3}$/
	end
	ip = args[0]
	gw = args[1]
	dns1 = args[2]
	dns2 = args[3]
	#puts "IP: #{ip}, GW: #{gw}, DNS1: #{dns1}, DNS2: #{dns2}"
	begin
		setup_network_manager(ip, gw, dns1, dns2)
	rescue
		puts "error: NetworkManager setup falied"
		exit -1
	end
	exit 0
end

main