1 # Copyright 2014 The Chromium OS Authors. All rights reserved. 2 # Use of this source code is governed by a BSD-style license that can be 3 # found in the LICENSE file. 4 5 import ConfigParser 6 import io 7 import collections 8 import logging 9 import shlex 10 import time 11 12 from autotest_lib.client.bin import utils 13 from autotest_lib.client.common_lib import error 14 from autotest_lib.client.common_lib.cros import dbus_send 15 16 BUS_NAME = 'org.freedesktop.Avahi' 17 INTERFACE_SERVER = 'org.freedesktop.Avahi.Server' 18 19 ServiceRecord = collections.namedtuple( 20 'ServiceRecord', 21 ['interface', 'protocol', 'name', 'record_type', 'domain', 22 'hostname', 'address', 'port', 'txt']) 23 24 25 def avahi_config(options, src_file='/etc/avahi/avahi-daemon.conf', host=None): 26 """Creates a temporary avahi-daemon.conf file with the specified changes. 27 28 Avahi daemon uses a text configuration file with sections and values 29 assigned to options on that section. This function creates a new config 30 file based on the one provided and a set of changes. The changes are 31 specified as triples of section, option and value that override the existing 32 options on the config file. If a value of None is specified for any triplet, 33 the corresponding option will be removed from the file. 34 35 @param options: A list of triplets of the form (section, option, value). 36 @param src_file: The default config file to use as a base for the changes. 37 @param host: An optional host object if running against a remote host. 38 @return: The filename of a temporary file with the new configuration file. 39 40 """ 41 run = utils.run if host is None else host.run 42 existing_config = run('cat %s 2> /dev/null' % src_file).stdout 43 conf = ConfigParser.SafeConfigParser() 44 conf.readfp(io.BytesIO(existing_config)) 45 46 for section, option, value in options: 47 if not conf.has_section(section): 48 conf.add_section(section) 49 if value is None: 50 conf.remove_option(section, option) 51 else: 52 conf.set(section, option, value) 53 54 tmp_conf_file = run('mktemp -t avahi-conf.XXXX').stdout.strip() 55 lines = [] 56 for section in conf.sections(): 57 lines.append('[%s]' % section) 58 for option in conf.options(section): 59 lines.append('%s=%s' % (option, conf.get(section, option))) 60 run('cat <<EOF >%s\n%s\nEOF\n' % (tmp_conf_file, '\n'.join(lines))) 61 return tmp_conf_file 62 63 64 def avahi_ping(host=None): 65 """Returns True when the avahi-deamon's DBus interface is ready. 66 67 After your launch avahi-daemon, there is a short period of time where the 68 daemon is running but the DBus interface isn't ready yet. This functions 69 blocks for a few seconds waiting for a ping response from the DBus API 70 and returns wether it got a response. 71 72 @param host: An optional host object if running against a remote host. 73 @return boolean: True if Avahi is up and in a stable state. 74 75 """ 76 result = dbus_send.dbus_send(BUS_NAME, INTERFACE_SERVER, '/', 'GetState', 77 host=host, timeout_seconds=2, 78 tolerate_failures=True) 79 # AVAHI_ENTRY_GROUP_ESTABLISHED == 2 80 return result is not None and result.response == 2 81 82 83 def avahi_start(config_file=None, host=None): 84 """Start avahi-daemon with the provided config file. 85 86 This function waits until the avahi-daemon is ready listening on the DBus 87 interface. If avahi fails to be ready after 10 seconds, an error is raised. 88 89 @param config_file: The filename of the avahi-daemon config file or None to 90 use the default. 91 @param host: An optional host object if running against a remote host. 92 93 """ 94 run = utils.run if host is None else host.run 95 env = '' 96 if config_file is not None: 97 env = ' AVAHI_DAEMON_CONF="%s"' % config_file 98 run('start avahi %s' % env, ignore_status=False) 99 # Wait until avahi is ready. 100 deadline = time.time() + 10. 101 while time.time() < deadline: 102 if avahi_ping(host=host): 103 return 104 time.sleep(0.1) 105 raise error.TestError('avahi-daemon is not ready after 10s running.') 106 107 108 def avahi_stop(ignore_status=False, host=None): 109 """Stop the avahi daemon. 110 111 @param ignore_status: True to ignore failures while stopping avahi. 112 @param host: An optional host object if running against a remote host. 113 114 """ 115 run = utils.run if host is None else host.run 116 run('stop avahi', ignore_status=ignore_status) 117 118 119 def avahi_start_on_iface(iface, host=None): 120 """Starts avahi daemon listening only on the provided interface. 121 122 @param iface: A string with the interface name. 123 @param host: An optional host object if running against a remote host. 124 125 """ 126 run = utils.run if host is None else host.run 127 opts = [('server', 'allow-interfaces', iface), 128 ('server', 'deny-interfaces', None)] 129 conf = avahi_config(opts, host=host) 130 avahi_start(config_file=conf, host=host) 131 run('rm %s' % conf) 132 133 134 def avahi_get_hostname(host=None): 135 """Get the lan-unique hostname of the the device. 136 137 @param host: An optional host object if running against a remote host. 138 @return string: the lan-unique hostname of the DUT. 139 140 """ 141 result = dbus_send.dbus_send( 142 BUS_NAME, INTERFACE_SERVER, '/', 'GetHostName', 143 host=host, timeout_seconds=2, tolerate_failures=True) 144 return None if result is None else result.response 145 146 147 def avahi_get_domain_name(host=None): 148 """Get the current domain name being used by Avahi. 149 150 @param host: An optional host object if running against a remote host. 151 @return string: the current domain name being used by Avahi. 152 153 """ 154 result = dbus_send.dbus_send( 155 BUS_NAME, INTERFACE_SERVER, '/', 'GetDomainName', 156 host=host, timeout_seconds=2, tolerate_failures=True) 157 return None if result is None else result.response 158 159 160 def avahi_browse(host=None, ignore_local=True): 161 """Browse mDNS service records with avahi-browse. 162 163 Some example avahi-browse output (lines are wrapped for readability): 164 165 localhost ~ # avahi-browse -tarlp 166 +;eth1;IPv4;E58E8561-3BCA-4910-ABC7-BD8779D7D761;_serbus._tcp;local 167 +;eth1;IPv4;E58E8561-3BCA-4910-ABC7-BD8779D7D761;_privet._tcp;local 168 =;eth1;IPv4;E58E8561-3BCA-4910-ABC7-BD8779D7D761;_serbus._tcp;local;\ 169 9bcd92bbc1f91f2ee9c9b2e754cfd22e.local;172.22.23.237;0;\ 170 "ver=1.0" "services=privet" "id=11FB0AD6-6C87-433E-8ACB-0C68EE78CDBD" 171 =;eth1;IPv4;E58E8561-3BCA-4910-ABC7-BD8779D7D761;_privet._tcp;local;\ 172 9bcd92bbc1f91f2ee9c9b2e754cfd22e.local;172.22.23.237;8080;\ 173 "ty=Unnamed Device" "txtvers=3" "services=_camera" "model_id=///" \ 174 "id=FEE9B312-1F2B-4B9B-813C-8482FA75E0DB" "flags=AB" "class=BB" 175 176 @param host: An optional host object if running against a remote host. 177 @param ignore_local: boolean True to ignore local service records. 178 @return list of ServiceRecord objects parsed from output. 179 180 """ 181 run = utils.run if host is None else host.run 182 flags = ['--terminate', # Terminate after looking for a short time. 183 '--all', # Show all services, regardless of type. 184 '--resolve', # Resolve the services discovered. 185 '--parsable', # Print service records in a parsable format. 186 ] 187 if ignore_local: 188 flags.append('--ignore-local') 189 result = run('avahi-browse %s' % ' '.join(flags)) 190 records = [] 191 for line in result.stdout.strip().splitlines(): 192 parts = line.split(';') 193 if parts[0] == '+': 194 # Skip it, just parse the resolved record. 195 continue 196 # Do minimal parsing of the TXT record. 197 parts[-1] = shlex.split(parts[-1]) 198 records.append(ServiceRecord(*parts[1:])) 199 logging.debug('Found %r', records[-1]) 200 return records 201
