| #!/bin/env python |
| |
| # Copyright 2015 The Chromium OS Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| import dbus |
| |
| SHILL_SERVICE_NAME = 'org.chromium.flimflam' |
| |
| INTERFACE_MANAGER = 'org.chromium.flimflam.Manager' |
| INTERFACE_SERVICE = 'org.chromium.flimflam.Service' |
| |
| STATIC_IP_CONFIG_KEY = 'StaticIPConfig' |
| SAVED_IP_CONFIG_KEY = 'SavedIPConfig' |
| NAME_SERVERS_KEY = 'NameServers' |
| |
| LOCAL_NAME_SERVER = '127.0.0.1' |
| |
| def main(): |
| bus = dbus.SystemBus() |
| manager = bus.get_object(SHILL_SERVICE_NAME, '/') |
| i_manager = dbus.Interface(manager, INTERFACE_MANAGER) |
| ethernet_path = i_manager.FindMatchingService({'Type': 'ethernet'}) |
| ethernet_service = bus.get_object(SHILL_SERVICE_NAME, ethernet_path) |
| i_ethernet_service = dbus.Interface(ethernet_service, INTERFACE_SERVICE) |
| properties = i_ethernet_service.GetProperties() |
| |
| # We must merge the nameservers received over DHCP with the extra nameserver |
| # we want to install. |
| static_ip_config = properties.get(STATIC_IP_CONFIG_KEY, {}) |
| static_name_servers = static_ip_config.get(NAME_SERVERS_KEY, []) |
| saved_ip_config = properties.get(SAVED_IP_CONFIG_KEY, {}) |
| saved_name_servers = saved_ip_config.get(NAME_SERVERS_KEY, []) |
| # By keeping LOCAL_NAME_SERVER first, dnsmasq can forward requests to any |
| # number of entries below. OTOH, if we keep the local nameserver last, there's |
| # a chance that we'll hit the maximum number of entries allowed in |
| # resolv.conf, and never make it to the local nameserver. |
| merged_name_servers = [dbus.String(LOCAL_NAME_SERVER)] + saved_name_servers |
| |
| |
| # NB: Careful now -- this script is usually launched by an upstart job every |
| # time shill connects. This means that by toggling shill's connection state, |
| # we're eventually relaunching this script. Therefore, we must ensure that we |
| # don't keep toggling shill when no new changes are made to the nameservers. |
| if set(merged_name_servers) == set(static_name_servers): |
| print('List of static nameservers is up-to-date. Exiting early.') |
| return |
| |
| static_ip_config[NAME_SERVERS_KEY] = merged_name_servers |
| i_ethernet_service.SetProperty(STATIC_IP_CONFIG_KEY, static_ip_config) |
| # If we updated the nameservers, we need to toggle the service connection to |
| # pick up the new nameservers. |
| try: |
| i_ethernet_service.Disconnect() |
| finally: |
| i_ethernet_service.Connect() |
| |
| |
| if __name__ == '__main__': |
| main() |
