88
88
except ImportError:
89
89
SO_BINDTODEVICE = None
91
if sys.version_info.major == 2:
95
92
stored_state_file = "clients.pickle"
97
94
logger = logging.getLogger()
95
syslogger = (logging.handlers.SysLogHandler
96
(facility = logging.handlers.SysLogHandler.LOG_DAEMON,
97
address = str("/dev/log")))
101
100
if_nametoindex = (ctypes.cdll.LoadLibrary
107
106
SIOCGIFINDEX = 0x8933 # From /usr/include/linux/sockios.h
108
107
with contextlib.closing(socket.socket()) as s:
109
108
ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
110
struct.pack(b"16s16x", interface))
111
interface_index = struct.unpack("I", ifreq[16:20])[0]
109
struct.pack(str("16s16x"),
111
interface_index = struct.unpack(str("I"),
112
113
return interface_index
115
116
def initlogger(debug, level=logging.WARNING):
116
117
"""init logger and add loglevel"""
119
syslogger = (logging.handlers.SysLogHandler
121
logging.handlers.SysLogHandler.LOG_DAEMON,
122
address = "/dev/log"))
123
119
syslogger.setFormatter(logging.Formatter
124
120
('Mandos [%(process)d]: %(levelname)s:'
225
221
class AvahiError(Exception):
226
222
def __init__(self, value, *args, **kwargs):
227
223
self.value = value
228
return super(AvahiError, self).__init__(value, *args,
224
super(AvahiError, self).__init__(value, *args, **kwargs)
225
def __unicode__(self):
226
return unicode(repr(self.value))
231
228
class AvahiServiceError(AvahiError):
282
279
" after %i retries, exiting.",
283
280
self.rename_count)
284
281
raise AvahiServiceError("Too many renames")
285
self.name = str(self.server
286
.GetAlternativeServiceName(self.name))
282
self.name = unicode(self.server
283
.GetAlternativeServiceName(self.name))
287
284
logger.info("Changing Zeroconf service name to %r ...",
338
335
elif state == avahi.ENTRY_GROUP_FAILURE:
339
336
logger.critical("Avahi: Error in group state changed %s",
341
raise AvahiGroupError("State changed: {!s}"
338
raise AvahiGroupError("State changed: {0!s}"
344
341
def cleanup(self):
395
392
"""Add the new name to the syslog messages"""
396
393
ret = AvahiService.rename(self)
397
394
syslogger.setFormatter(logging.Formatter
398
('Mandos ({}) [%(process)d]:'
395
('Mandos ({0}) [%(process)d]:'
399
396
' %(levelname)s: %(message)s'
400
397
.format(self.name)))
401
def timedelta_to_milliseconds(td):
402
"Convert a datetime.timedelta() to milliseconds"
403
return ((td.days * 24 * 60 * 60 * 1000)
404
+ (td.seconds * 1000)
405
+ (td.microseconds // 1000))
404
408
class Client(object):
405
409
"""A representation of a client host served by this server.
461
465
"enabled": "True",
468
def timeout_milliseconds(self):
469
"Return the 'timeout' attribute in milliseconds"
470
return timedelta_to_milliseconds(self.timeout)
472
def extended_timeout_milliseconds(self):
473
"Return the 'extended_timeout' attribute in milliseconds"
474
return timedelta_to_milliseconds(self.extended_timeout)
476
def interval_milliseconds(self):
477
"Return the 'interval' attribute in milliseconds"
478
return timedelta_to_milliseconds(self.interval)
480
def approval_delay_milliseconds(self):
481
return timedelta_to_milliseconds(self.approval_delay)
465
484
def config_parser(config):
466
485
"""Construct a new dict of client settings of this form:
491
510
"rb") as secfile:
492
511
client["secret"] = secfile.read()
494
raise TypeError("No secret or secfile for section {}"
513
raise TypeError("No secret or secfile for section {0}"
495
514
.format(section))
496
515
client["timeout"] = string_to_delta(section["timeout"])
497
516
client["extended_timeout"] = string_to_delta(
514
533
server_settings = {}
515
534
self.server_settings = server_settings
516
535
# adding all client settings
517
for setting, value in settings.items():
536
for setting, value in settings.iteritems():
518
537
setattr(self, setting, value)
603
622
if self.checker_initiator_tag is not None:
604
623
gobject.source_remove(self.checker_initiator_tag)
605
624
self.checker_initiator_tag = (gobject.timeout_add
607
.total_seconds() * 1000),
625
(self.interval_milliseconds(),
608
626
self.start_checker))
609
627
# Schedule a disable() when 'timeout' has passed
610
628
if self.disable_initiator_tag is not None:
611
629
gobject.source_remove(self.disable_initiator_tag)
612
630
self.disable_initiator_tag = (gobject.timeout_add
614
.total_seconds() * 1000),
631
(self.timeout_milliseconds(),
616
633
# Also start a new checker *right now*.
617
634
self.start_checker()
649
666
self.disable_initiator_tag = None
650
667
if getattr(self, "enabled", False):
651
668
self.disable_initiator_tag = (gobject.timeout_add
652
(int(timeout.total_seconds()
653
* 1000), self.disable))
669
(timedelta_to_milliseconds
670
(timeout), self.disable))
654
671
self.expires = datetime.datetime.utcnow() + timeout
656
673
def need_approval(self):
687
704
# Start a new checker if needed
688
705
if self.checker is None:
689
706
# Escape attributes for the shell
690
escaped_attrs = { attr:
691
re.escape(str(getattr(self, attr)))
692
for attr in self.runtime_expansions }
707
escaped_attrs = dict(
708
(attr, re.escape(unicode(getattr(self, attr))))
710
self.runtime_expansions)
694
712
command = self.checker_command % escaped_attrs
695
713
except TypeError as error:
776
794
# "Set" method, so we fail early here:
777
795
if byte_arrays and signature != "ay":
778
796
raise ValueError("Byte arrays not supported for non-'ay'"
779
" signature {!r}".format(signature))
797
" signature {0!r}".format(signature))
780
798
def decorator(func):
781
799
func._dbus_is_property = True
782
800
func._dbus_interface = dbus_interface
830
848
class DBusPropertyException(dbus.exceptions.DBusException):
831
849
"""A base class for D-Bus property-related exceptions
851
def __unicode__(self):
852
return unicode(str(self))
835
855
class DBusPropertyAccessException(DBusPropertyException):
836
856
"""A property's access permissions disallows an operation.
859
879
If called like _is_dbus_thing("method") it returns a function
860
880
suitable for use as predicate to inspect.getmembers().
862
return lambda obj: getattr(obj, "_dbus_is_{}".format(thing),
882
return lambda obj: getattr(obj, "_dbus_is_{0}".format(thing),
865
885
def _get_all_dbus_things(self, thing):
915
935
# signatures other than "ay".
916
936
if prop._dbus_signature != "ay":
917
937
raise ValueError("Byte arrays not supported for non-"
918
"'ay' signature {!r}"
938
"'ay' signature {0!r}"
919
939
.format(prop._dbus_signature))
920
940
value = dbus.ByteArray(b''.join(chr(byte)
921
941
for byte in value))
987
1007
"_dbus_annotations",
989
for name, value in annots.items():
1009
for name, value in annots.iteritems():
990
1010
ann_tag = document.createElement(
992
1012
ann_tag.setAttribute("name", name)
995
1015
# Add interface annotation tags
996
1016
for annotation, value in dict(
997
1017
itertools.chain.from_iterable(
998
annotations().items()
1018
annotations().iteritems()
999
1019
for name, annotations in
1000
1020
self._get_all_dbus_things("interface")
1001
1021
if name == if_tag.getAttribute("name")
1003
1023
ann_tag = document.createElement("annotation")
1004
1024
ann_tag.setAttribute("name", annotation)
1005
1025
ann_tag.setAttribute("value", value)
1062
1082
def wrapper(cls):
1063
1083
for orig_interface_name, alt_interface_name in (
1064
alt_interface_names.items()):
1084
alt_interface_names.iteritems()):
1066
1086
interface_names = set()
1067
1087
# Go though all attributes of the class
1184
1204
attribute.func_closure)))
1186
1206
# Deprecate all alternate interfaces
1187
iname="_AlternateDBusNames_interface_annotation{}"
1207
iname="_AlternateDBusNames_interface_annotation{0}"
1188
1208
for interface_name in interface_names:
1189
1209
@dbus_interface_annotations(interface_name)
1190
1210
def func(self):
1199
1219
if interface_names:
1200
1220
# Replace the class with a new subclass of it with
1201
1221
# methods, signals, etc. as created above.
1202
cls = type(b"{}Alternate".format(cls.__name__),
1222
cls = type(b"{0}Alternate".format(cls.__name__),
1225
1245
Client.__init__(self, *args, **kwargs)
1226
1246
# Only now, when this client is initialized, can it show up on
1228
client_object_name = str(self.name).translate(
1248
client_object_name = unicode(self.name).translate(
1229
1249
{ord("."): ord("_"),
1230
1250
ord("-"): ord("_")})
1231
1251
self.dbus_object_path = (dbus.ObjectPath
1246
1266
to the D-Bus. Default: no transform
1247
1267
variant_level: D-Bus variant level. Default: 1
1249
attrname = "_{}".format(dbus_name)
1269
attrname = "_{0}".format(dbus_name)
1250
1270
def setter(self, value):
1251
1271
if hasattr(self, "dbus_object_path"):
1252
1272
if (not hasattr(self, attrname) or
1282
1302
approval_delay = notifychangeproperty(dbus.UInt64,
1283
1303
"ApprovalDelay",
1285
lambda td: td.total_seconds()
1305
timedelta_to_milliseconds)
1287
1306
approval_duration = notifychangeproperty(
1288
1307
dbus.UInt64, "ApprovalDuration",
1289
type_func = lambda td: td.total_seconds() * 1000)
1308
type_func = timedelta_to_milliseconds)
1290
1309
host = notifychangeproperty(dbus.String, "Host")
1291
1310
timeout = notifychangeproperty(dbus.UInt64, "Timeout",
1292
type_func = lambda td:
1293
td.total_seconds() * 1000)
1312
timedelta_to_milliseconds)
1294
1313
extended_timeout = notifychangeproperty(
1295
1314
dbus.UInt64, "ExtendedTimeout",
1296
type_func = lambda td: td.total_seconds() * 1000)
1315
type_func = timedelta_to_milliseconds)
1297
1316
interval = notifychangeproperty(dbus.UInt64,
1300
lambda td: td.total_seconds()
1319
timedelta_to_milliseconds)
1302
1320
checker_command = notifychangeproperty(dbus.String, "Checker")
1304
1322
del notifychangeproperty
1332
1350
*args, **kwargs)
1334
1352
def start_checker(self, *args, **kwargs):
1335
old_checker_pid = getattr(self.checker, "pid", None)
1353
old_checker = self.checker
1354
if self.checker is not None:
1355
old_checker_pid = self.checker.pid
1357
old_checker_pid = None
1336
1358
r = Client.start_checker(self, *args, **kwargs)
1337
1359
# Only if new checker process was started
1338
1360
if (self.checker is not None
1348
1370
def approve(self, value=True):
1349
1371
self.approved = value
1350
gobject.timeout_add(int(self.approval_duration.total_seconds()
1351
* 1000), self._reset_approved)
1372
gobject.timeout_add(timedelta_to_milliseconds
1373
(self.approval_duration),
1374
self._reset_approved)
1352
1375
self.send_changedstate()
1354
1377
## D-Bus methods, signals & properties
1457
1480
access="readwrite")
1458
1481
def ApprovalDelay_dbus_property(self, value=None):
1459
1482
if value is None: # get
1460
return dbus.UInt64(self.approval_delay.total_seconds()
1483
return dbus.UInt64(self.approval_delay_milliseconds())
1462
1484
self.approval_delay = datetime.timedelta(0, 0, 0, value)
1464
1486
# ApprovalDuration - property
1466
1488
access="readwrite")
1467
1489
def ApprovalDuration_dbus_property(self, value=None):
1468
1490
if value is None: # get
1469
return dbus.UInt64(self.approval_duration.total_seconds()
1491
return dbus.UInt64(timedelta_to_milliseconds(
1492
self.approval_duration))
1471
1493
self.approval_duration = datetime.timedelta(0, 0, 0, value)
1473
1495
# Name - property
1486
1508
def Host_dbus_property(self, value=None):
1487
1509
if value is None: # get
1488
1510
return dbus.String(self.host)
1489
self.host = str(value)
1511
self.host = unicode(value)
1491
1513
# Created - property
1492
1514
@dbus_service_property(_interface, signature="s", access="read")
1539
1561
access="readwrite")
1540
1562
def Timeout_dbus_property(self, value=None):
1541
1563
if value is None: # get
1542
return dbus.UInt64(self.timeout.total_seconds() * 1000)
1564
return dbus.UInt64(self.timeout_milliseconds())
1543
1565
old_timeout = self.timeout
1544
1566
self.timeout = datetime.timedelta(0, 0, 0, value)
1545
1567
# Reschedule disabling
1556
1578
gobject.source_remove(self.disable_initiator_tag)
1557
1579
self.disable_initiator_tag = (
1558
1580
gobject.timeout_add(
1559
int((self.expires - now).total_seconds()
1560
* 1000), self.disable))
1581
timedelta_to_milliseconds(self.expires - now),
1562
1584
# ExtendedTimeout - property
1563
1585
@dbus_service_property(_interface, signature="t",
1564
1586
access="readwrite")
1565
1587
def ExtendedTimeout_dbus_property(self, value=None):
1566
1588
if value is None: # get
1567
return dbus.UInt64(self.extended_timeout.total_seconds()
1589
return dbus.UInt64(self.extended_timeout_milliseconds())
1569
1590
self.extended_timeout = datetime.timedelta(0, 0, 0, value)
1571
1592
# Interval - property
1573
1594
access="readwrite")
1574
1595
def Interval_dbus_property(self, value=None):
1575
1596
if value is None: # get
1576
return dbus.UInt64(self.interval.total_seconds() * 1000)
1597
return dbus.UInt64(self.interval_milliseconds())
1577
1598
self.interval = datetime.timedelta(0, 0, 0, value)
1578
1599
if getattr(self, "checker_initiator_tag", None) is None:
1590
1611
def Checker_dbus_property(self, value=None):
1591
1612
if value is None: # get
1592
1613
return dbus.String(self.checker_command)
1593
self.checker_command = str(value)
1614
self.checker_command = unicode(value)
1595
1616
# CheckerRunning - property
1596
1617
@dbus_service_property(_interface, signature="b",
1612
1633
@dbus_service_property(_interface, signature="ay",
1613
1634
access="write", byte_arrays=True)
1614
1635
def Secret_dbus_property(self, value):
1615
self.secret = bytes(value)
1636
self.secret = str(value)
1652
1673
def handle(self):
1653
1674
with contextlib.closing(self.server.child_pipe) as child_pipe:
1654
1675
logger.info("TCP connection from: %s",
1655
str(self.client_address))
1676
unicode(self.client_address))
1656
1677
logger.debug("Pipe FD: %d",
1657
1678
self.server.child_pipe.fileno())
1739
1760
if self.server.use_dbus:
1740
1761
# Emit D-Bus signal
1741
1762
client.NeedApproval(
1742
client.approval_delay.total_seconds()
1743
* 1000, client.approved_by_default)
1763
client.approval_delay_milliseconds(),
1764
client.approved_by_default)
1745
1766
logger.warning("Client %s was not approved",
1752
1773
#wait until timeout or approved
1753
1774
time = datetime.datetime.now()
1754
1775
client.changedstate.acquire()
1755
client.changedstate.wait(delay.total_seconds())
1776
client.changedstate.wait(
1777
float(timedelta_to_milliseconds(delay)
1756
1779
client.changedstate.release()
1757
1780
time2 = datetime.datetime.now()
1758
1781
if (time2 - time) >= delay:
1958
1981
self.socket.setsockopt(socket.SOL_SOCKET,
1959
1982
SO_BINDTODEVICE,
1960
(self.interface + "\0")
1983
str(self.interface + '\0'))
1962
1984
except socket.error as error:
1963
1985
if error.errno == errno.EPERM:
1964
1986
logger.error("No permission to bind to"
2167
2189
token_duration = Token(re.compile(r"P"), None,
2168
2190
frozenset((token_year, token_month,
2169
2191
token_day, token_time,
2171
2193
# Define starting values
2172
2194
value = datetime.timedelta() # Value so far
2173
2195
found_token = None
2174
followers = frozenset((token_duration,)) # Following valid tokens
2196
followers = frozenset(token_duration,) # Following valid tokens
2175
2197
s = duration # String left to parse
2176
2198
# Loop until end token is found
2177
2199
while found_token is not token_end:
2237
2259
elif suffix == "w":
2238
2260
delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
2240
raise ValueError("Unknown suffix {!r}"
2262
raise ValueError("Unknown suffix {0!r}"
2241
2263
.format(suffix))
2242
2264
except IndexError as e:
2243
2265
raise ValueError(*(e.args))
2260
2282
# Close all standard open file descriptors
2261
2283
null = os.open(os.devnull, os.O_NOCTTY | os.O_RDWR)
2262
2284
if not stat.S_ISCHR(os.fstat(null).st_mode):
2263
raise OSError(errno.ENODEV, "{} not a character device"
2285
raise OSError(errno.ENODEV,
2286
"{0} not a character device"
2264
2287
.format(os.devnull))
2265
2288
os.dup2(null, sys.stdin.fileno())
2266
2289
os.dup2(null, sys.stdout.fileno())
2277
2300
parser = argparse.ArgumentParser()
2278
2301
parser.add_argument("-v", "--version", action="version",
2279
version = "%(prog)s {}".format(version),
2302
version = "%(prog)s {0}".format(version),
2280
2303
help="show version number and exit")
2281
2304
parser.add_argument("-i", "--interface", metavar="IF",
2282
2305
help="Bind to interface IF")
2315
2338
help="Directory to save/restore state in")
2316
2339
parser.add_argument("--foreground", action="store_true",
2317
2340
help="Run in foreground", default=None)
2318
parser.add_argument("--no-zeroconf", action="store_false",
2319
dest="zeroconf", help="Do not use Zeroconf",
2322
2342
options = parser.parse_args()
2374
2393
for option in ("interface", "address", "port", "debug",
2375
2394
"priority", "servicename", "configdir",
2376
2395
"use_dbus", "use_ipv6", "debuglevel", "restore",
2377
"statedir", "socket", "foreground", "zeroconf"):
2396
"statedir", "socket", "foreground"):
2378
2397
value = getattr(options, option)
2379
2398
if value is not None:
2380
2399
server_settings[option] = value
2382
2401
# Force all strings to be unicode
2383
2402
for option in server_settings.keys():
2384
if isinstance(server_settings[option], bytes):
2385
server_settings[option] = (server_settings[option]
2403
if type(server_settings[option]) is str:
2404
server_settings[option] = unicode(server_settings[option])
2387
2405
# Force all boolean options to be boolean
2388
2406
for option in ("debug", "use_dbus", "use_ipv6", "restore",
2389
"foreground", "zeroconf"):
2390
2408
server_settings[option] = bool(server_settings[option])
2391
2409
# Debug implies foreground
2392
2410
if server_settings["debug"]:
2396
2414
##################################################################
2398
if (not server_settings["zeroconf"] and
2399
not (server_settings["port"]
2400
or server_settings["socket"] != "")):
2401
parser.error("Needs port or socket to work without"
2404
2416
# For convenience
2405
2417
debug = server_settings["debug"]
2406
2418
debuglevel = server_settings["debuglevel"]
2409
2421
stored_state_path = os.path.join(server_settings["statedir"],
2410
2422
stored_state_file)
2411
2423
foreground = server_settings["foreground"]
2412
zeroconf = server_settings["zeroconf"]
2415
2426
initlogger(debug, logging.DEBUG)
2423
2434
if server_settings["servicename"] != "Mandos":
2424
2435
syslogger.setFormatter(logging.Formatter
2425
('Mandos ({}) [%(process)d]:'
2436
('Mandos ({0}) [%(process)d]:'
2426
2437
' %(levelname)s: %(message)s'
2427
2438
.format(server_settings
2428
2439
["servicename"])))
2436
2447
global mandos_dbus_service
2437
2448
mandos_dbus_service = None
2440
if server_settings["socket"] != "":
2441
socketfd = server_settings["socket"]
2442
2450
tcp_server = MandosServer((server_settings["address"],
2443
2451
server_settings["port"]),
2448
2456
gnutls_priority=
2449
2457
server_settings["priority"],
2450
2458
use_dbus=use_dbus,
2459
socketfd=(server_settings["socket"]
2452
2461
if not foreground:
2453
2462
pidfilename = "/run/mandos.pid"
2454
2463
if not os.path.isdir("/run/."):
2524
2533
use_dbus = False
2525
2534
server_settings["use_dbus"] = False
2526
2535
tcp_server.use_dbus = False
2528
protocol = avahi.PROTO_INET6 if use_ipv6 else avahi.PROTO_INET
2529
service = AvahiServiceToSyslog(name =
2530
server_settings["servicename"],
2531
servicetype = "_mandos._tcp",
2532
protocol = protocol, bus = bus)
2533
if server_settings["interface"]:
2534
service.interface = (if_nametoindex
2535
(server_settings["interface"]
2536
protocol = avahi.PROTO_INET6 if use_ipv6 else avahi.PROTO_INET
2537
service = AvahiServiceToSyslog(name =
2538
server_settings["servicename"],
2539
servicetype = "_mandos._tcp",
2540
protocol = protocol, bus = bus)
2541
if server_settings["interface"]:
2542
service.interface = (if_nametoindex
2543
(str(server_settings["interface"])))
2538
2545
global multiprocessing_manager
2539
2546
multiprocessing_manager = multiprocessing.Manager()
2563
2570
os.remove(stored_state_path)
2564
2571
except IOError as e:
2565
2572
if e.errno == errno.ENOENT:
2566
logger.warning("Could not load persistent state: {}"
2573
logger.warning("Could not load persistent state: {0}"
2567
2574
.format(os.strerror(e.errno)))
2569
2576
logger.critical("Could not load persistent state:",
2605
2612
if datetime.datetime.utcnow() >= client["expires"]:
2606
2613
if not client["last_checked_ok"]:
2607
2614
logger.warning(
2608
"disabling client {} - Client never "
2615
"disabling client {0} - Client never "
2609
2616
"performed a successful checker"
2610
2617
.format(client_name))
2611
2618
client["enabled"] = False
2612
2619
elif client["last_checker_status"] != 0:
2613
2620
logger.warning(
2614
"disabling client {} - Client last"
2615
" checker failed with error code {}"
2621
"disabling client {0} - Client "
2622
"last checker failed with error code {1}"
2616
2623
.format(client_name,
2617
2624
client["last_checker_status"]))
2618
2625
client["enabled"] = False
2631
2638
except PGPError:
2632
2639
# If decryption fails, we use secret from new settings
2633
logger.debug("Failed to decrypt {} old secret"
2640
logger.debug("Failed to decrypt {0} old secret"
2634
2641
.format(client_name))
2635
2642
client["secret"] = (
2636
2643
client_settings[client_name]["secret"])
2644
2651
clients_data[client_name] = client_settings[client_name]
2646
2653
# Create all client objects
2647
for client_name, client in clients_data.items():
2654
for client_name, client in clients_data.iteritems():
2648
2655
tcp_server.clients[client_name] = client_class(
2649
2656
name = client_name, settings = client,
2650
2657
server_settings = server_settings)
2755
2761
# A list of attributes that can not be pickled
2757
exclude = { "bus", "changedstate", "secret",
2758
"checker", "server_settings" }
2763
exclude = set(("bus", "changedstate", "secret",
2764
"checker", "server_settings"))
2759
2765
for name, typ in (inspect.getmembers
2760
2766
(dbus.service.Object)):
2761
2767
exclude.add(name)
2784
2790
except NameError:
2786
2792
if e.errno in (errno.ENOENT, errno.EACCES, errno.EEXIST):
2787
logger.warning("Could not save persistent state: {}"
2793
logger.warning("Could not save persistent state: {0}"
2788
2794
.format(os.strerror(e.errno)))
2790
2796
logger.warning("Could not save persistent state:",
2819
2825
tcp_server.server_activate()
2821
2827
# Find out what port we got
2823
service.port = tcp_server.socket.getsockname()[1]
2828
service.port = tcp_server.socket.getsockname()[1]
2825
2830
logger.info("Now listening on address %r, port %d,"
2826
2831
" flowinfo %d, scope_id %d",
2832
2837
#service.interface = tcp_server.socket.getsockname()[3]
2836
# From the Avahi example code
2839
except dbus.exceptions.DBusException as error:
2840
logger.critical("D-Bus Exception", exc_info=error)
2843
# End of Avahi example code
2840
# From the Avahi example code
2843
except dbus.exceptions.DBusException as error:
2844
logger.critical("D-Bus Exception", exc_info=error)
2847
# End of Avahi example code
2845
2849
gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
2846
2850
lambda *args, **kwargs: