| # Copyright 2014 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 logging |
| import time |
| |
| from autotest_lib.client.common_lib import error |
| from autotest_lib.client.common_lib.cros import avahi_utils |
| from autotest_lib.client.common_lib.cros import virtual_ethernet_pair |
| from autotest_lib.client.common_lib.cros.network import netblock |
| from autotest_lib.client.cros import network_chroot |
| from autotest_lib.client.cros import service_stopper |
| from autotest_lib.client.cros import tcpdump |
| |
| |
| class ChrootedAvahi(object): |
| """Helper object to start up avahi in a network chroot. |
| |
| Creates a virtual ethernet pair to enable communication with avahi. |
| Does the necessary work to make avahi appear on DBus and allow it |
| to claim its canonical service name. |
| |
| """ |
| |
| SERVICES_TO_STOP = ['avahi'] |
| # This side has to be called something special to avoid shill touching it. |
| MONITOR_IF_IP = netblock.from_addr('10.9.8.1/24') |
| # We'll drop the Avahi side into our network namespace. |
| AVAHI_IF_IP = netblock.from_addr('10.9.8.2/24') |
| AVAHI_IF_NAME = 'pseudoethernet0' |
| TCPDUMP_FILE_PATH = '/var/log/peerd_dump.pcap' |
| AVAHI_CONFIG_FILE = 'etc/avahi/avahi-daemon.conf' |
| AVAHI_CONFIGS = { |
| AVAHI_CONFIG_FILE : |
| '[server]\n' |
| 'host-name-from-machine-id=yes\n' |
| 'browse-domains=\n' |
| 'use-ipv4=yes\n' |
| 'use-ipv6=no\n' |
| 'ratelimit-interval-usec=1000000\n' |
| 'ratelimit-burst=1000\n' |
| '[wide-area]\n' |
| 'enable-wide-area=no\n' |
| '[publish]\n' |
| 'publish-hinfo=no\n' |
| 'publish-workstation=no\n' |
| 'publish-aaaa-on-ipv4=no\n' |
| 'publish-a-on-ipv6=no\n' |
| '[rlimits]\n' |
| 'rlimit-core=0\n' |
| 'rlimit-data=4194304\n' |
| 'rlimit-fsize=1024\n' |
| 'rlimit-nofile=768\n' |
| 'rlimit-stack=4194304\n' |
| 'rlimit-nproc=10\n', |
| |
| 'etc/passwd' : |
| 'root:x:0:0:root:/root:/bin/bash\n' |
| 'avahi:*:238:238::/dev/null:/bin/false\n', |
| |
| 'etc/group' : |
| 'avahi:x:238:\n', |
| } |
| AVAHI_LOG_FILE = '/var/log/avahi.log' |
| AVAHI_PID_FILE = 'var/run/avahi-daemon/pid' |
| AVAHI_UP_TIMEOUT_SECONDS = 10 |
| |
| |
| def __init__(self, unchrooted_interface_name='pseudoethernet1'): |
| """Construct a chrooted instance of Avahi. |
| |
| @param unchrooted_interface_name: string name of interface to leave |
| outside the network chroot. This interface will be connected |
| to the end Avahi is listening on. |
| |
| """ |
| self._unchrooted_interface_name = unchrooted_interface_name |
| self._services = None |
| self._vif = None |
| self._tcpdump = None |
| self._chroot = None |
| |
| |
| @property |
| def unchrooted_interface_name(self): |
| """Get the name of the end of the VirtualEthernetPair not in the chroot. |
| |
| The network chroot works by isolating avahi inside with one end of a |
| virtual ethernet pair. The outside world needs to interact with the |
| other end in order to talk to avahi. |
| |
| @return name of interface not inside the chroot. |
| |
| """ |
| return self._unchrooted_interface_name |
| |
| |
| @property |
| def avahi_interface_addr(self): |
| """@return string ip address of interface belonging to avahi.""" |
| return self.AVAHI_IF_IP.addr |
| |
| |
| @property |
| def hostname(self): |
| """@return string hostname claimed by avahi on |self.dns_domain|.""" |
| return avahi_utils.avahi_get_hostname() |
| |
| |
| @property |
| def dns_domain(self): |
| """@return string DNS domain in use by avahi (e.g. 'local').""" |
| return avahi_utils.avahi_get_domain_name() |
| |
| |
| def start(self): |
| """Start up the chrooted Avahi instance.""" |
| # Prevent weird interactions between services which talk to Avahi. |
| # TODO(wiley) Does Chrome need to die here as well? |
| self._services = service_stopper.ServiceStopper( |
| self.SERVICES_TO_STOP) |
| self._services.stop_services() |
| # We don't want Avahi talking to the real world, so give it a nice |
| # fake interface to use. We'll watch the other half of the pair. |
| self._vif = virtual_ethernet_pair.VirtualEthernetPair( |
| interface_name=self.unchrooted_interface_name, |
| peer_interface_name=self.AVAHI_IF_NAME, |
| interface_ip=self.MONITOR_IF_IP.netblock, |
| peer_interface_ip=self.AVAHI_IF_IP.netblock, |
| # Moving one end into the chroot causes errors. |
| ignore_shutdown_errors=True) |
| self._vif.setup() |
| if not self._vif.is_healthy: |
| raise error.TestError('Failed to setup virtual ethernet pair.') |
| # By default, take a packet capture of everything Avahi sends out. |
| self._tcpdump = tcpdump.Tcpdump(self.unchrooted_interface_name, |
| self.TCPDUMP_FILE_PATH) |
| # We're going to run Avahi in a network namespace to avoid interactions |
| # with the outside world. |
| self._chroot = network_chroot.NetworkChroot(self.AVAHI_IF_NAME, |
| self.AVAHI_IF_IP.addr, |
| self.AVAHI_IF_IP.prefix_len) |
| self._chroot.add_config_templates(self.AVAHI_CONFIGS) |
| self._chroot.add_root_directories(['etc/avahi', 'etc/avahi/services']) |
| self._chroot.add_copied_config_files(['etc/resolv.conf', |
| 'etc/avahi/hosts']) |
| self._chroot.add_startup_command( |
| '/usr/sbin/avahi-daemon --file=/%s >%s 2>&1' % |
| (self.AVAHI_CONFIG_FILE, self.AVAHI_LOG_FILE)) |
| self._chroot.bridge_dbus_namespaces() |
| self._chroot.startup() |
| # Wait for Avahi to come up, claim its DBus name, settle on a hostname. |
| start_time = time.time() |
| while time.time() - start_time < self.AVAHI_UP_TIMEOUT_SECONDS: |
| if avahi_utils.avahi_ping(): |
| break |
| time.sleep(0.2) |
| else: |
| raise error.TestFail('Avahi did not come up in time.') |
| |
| |
| def close(self): |
| """Clean up the chrooted Avahi instance.""" |
| if self._chroot: |
| # TODO(wiley) This is sloppy. Add a helper to move the logs over. |
| for line in self._chroot.get_log_contents().splitlines(): |
| logging.debug(line) |
| self._chroot.kill_pid_file(self.AVAHI_PID_FILE) |
| self._chroot.shutdown() |
| if self._tcpdump: |
| self._tcpdump.stop() |
| if self._vif: |
| self._vif.teardown() |
| if self._services: |
| self._services.restore_services() |
