6
6
# This program is partly derived from an example program for an Avahi
7
7
# service publisher, downloaded from
8
8
# <http://avahi.org/wiki/PythonPublishExample>. This includes the
9
# following functions: "add_service", "remove_service",
9
# following functions: "AvahiService.add", "AvahiService.remove",
10
10
# "server_state_changed", "entry_group_state_changed", and some lines
13
# Everything else is Copyright © 2007-2008 Teddy Hogeborn and Björn
14
# Copyright © 2007-2008 Teddy Hogeborn & Björn Påhlsson
16
16
# This program is free software: you can redistribute it and/or modify
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17
# it under the terms of the GNU General Public License as published by
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81
logger.addHandler(syslogger)
85
# This variable is used to optionally bind to a specified interface.
86
# It is a global variable to fit in with the other variables from the
88
serviceInterface = avahi.IF_UNSPEC
85
class AvahiError(Exception):
86
def __init__(self, value):
89
return repr(self.value)
91
class AvahiServiceError(AvahiError):
94
class AvahiGroupError(AvahiError):
98
class AvahiService(object):
100
interface: integer; avahi.IF_UNSPEC or an interface index.
101
Used to optionally bind to the specified interface.
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name = string; Example: "Mandos"
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type = string; Example: "_mandos._tcp".
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See <http://www.dns-sd.org/ServiceTypes.html>
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port = integer; what port to announce
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TXT = list of strings; TXT record for the service
107
domain = string; Domain to publish on, default to .local if empty.
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host = string; Host to publish records for, default to localhost
110
max_renames = integer; maximum number of renames
111
rename_count = integer; counter so we only rename after collisions
112
a sensible number of times
114
def __init__(self, interface = avahi.IF_UNSPEC, name = None,
115
type = None, port = None, TXT = None, domain = "",
116
host = "", max_renames = 12):
117
"""An Avahi (Zeroconf) service. """
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self.interface = interface
128
self.rename_count = 0
130
"""Derived from the Avahi example code"""
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if self.rename_count >= self.max_renames:
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logger.critical(u"No suitable service name found after %i"
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u" retries, exiting.", rename_count)
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raise AvahiServiceError("Too many renames")
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name = server.GetAlternativeServiceName(name)
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logger.notice(u"Changing name to %r ...", name)
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self.rename_count += 1
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"""Derived from the Avahi example code"""
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if group is not None:
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"""Derived from the Avahi example code"""
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group = dbus.Interface\
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(bus.get_object(avahi.DBUS_NAME,
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server.EntryGroupNew()),
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avahi.DBUS_INTERFACE_ENTRY_GROUP)
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group.connect_to_signal('StateChanged',
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entry_group_state_changed)
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logger.debug(u"Adding service '%s' of type '%s' ...",
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service.name, service.type)
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self.interface, # interface
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avahi.PROTO_INET6, # protocol
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dbus.UInt32(0), # flags
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self.name, self.type,
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self.domain, self.host,
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dbus.UInt16(self.port),
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avahi.string_array_to_txt_array(self.TXT))
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166
# From the Avahi example code:
90
serviceName = "Mandos"
91
serviceType = "_mandos._tcp" # http://www.dns-sd.org/ServiceTypes.html
92
servicePort = None # Not known at startup
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serviceTXT = [] # TXT record for the service
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domain = "" # Domain to publish on, default to .local
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host = "" # Host to publish records for, default to localhost
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group = None #our entry group
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rename_count = 12 # Counter so we only rename after collisions a
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# sensible number of times
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group = None # our entry group
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168
# End of Avahi example code
107
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uniquely identify the client
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177
secret: bytestring; sent verbatim (over TLS) to client
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178
fqdn: string (FQDN); available for use by the checker command
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created: datetime.datetime()
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last_seen: datetime.datetime() or None if not yet seen
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timeout: datetime.timedelta(); How long from last_seen until
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this client is invalid
179
created: datetime.datetime(); object creation, not client host
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last_checked_ok: datetime.datetime() or None if not yet checked OK
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timeout: datetime.timedelta(); How long from last_checked_ok
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until this client is invalid
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interval: datetime.timedelta(); How often to start a new checker
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184
stop_hook: If set, called by stop() as stop_hook(self)
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checker: subprocess.Popen(); a running checker process used
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to see if the client lives.
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Is None if no process is running.
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'None' if no process is running.
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checker_initiator_tag: a gobject event source tag, or None
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stop_initiator_tag: - '' -
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checker_callback_tag: - '' -
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checker_command: string; External command which is run to check if
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client lives. %()s expansions are done at
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client lives. %() expansions are done at
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193
runtime with vars(self) as dict, so that for
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instance %(name)s can be used in the command.
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195
Private attibutes:
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_timeout: Real variable for 'timeout'
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197
_interval: Real variable for 'interval'
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_timeout_milliseconds: Used by gobject.timeout_add()
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_timeout_milliseconds: Used when calling gobject.timeout_add()
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_interval_milliseconds: - '' -
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201
def _set_timeout(self, timeout):
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221
interval = property(lambda self: self._interval,
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223
del _set_interval
155
def __init__(self, name=None, options=None, stop_hook=None,
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fingerprint=None, secret=None, secfile=None,
157
fqdn=None, timeout=None, interval=-1, checker=None):
224
def __init__(self, name=None, stop_hook=None, fingerprint=None,
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secret=None, secfile=None, fqdn=None, timeout=None,
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interval=-1, checker=None):
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"""Note: the 'checker' argument sets the 'checker_command'
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228
attribute and not the 'checker' attribute.."""
230
logger.debug(u"Creating client %r", self.name)
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# Uppercase and remove spaces from fingerprint
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# for later comparison purposes with return value of
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# the fingerprint() function
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234
self.fingerprint = fingerprint.upper().replace(u" ", u"")
235
logger.debug(u" Fingerprint: %s", self.fingerprint)
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self.secret = secret.decode(u"base64")
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self.secret = sf.read()
172
raise RuntimeError(u"No secret or secfile for client %s"
174
self.fqdn = fqdn # string
243
raise TypeError(u"No secret or secfile for client %s"
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self.created = datetime.datetime.now()
176
self.last_seen = None
178
self.timeout = options.timeout
180
self.timeout = string_to_delta(timeout)
182
self.interval = options.interval
184
self.interval = string_to_delta(interval)
247
self.last_checked_ok = None
248
self.timeout = string_to_delta(timeout)
249
self.interval = string_to_delta(interval)
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self.stop_hook = stop_hook
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251
self.checker = None
187
252
self.checker_initiator_tag = None
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270
"""Stop this client.
206
The possibility that this client might be restarted is left
207
open, but not currently used."""
271
The possibility that a client might be restarted is left open,
272
but not currently used."""
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# If this client doesn't have a secret, it is already stopped.
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logger.debug(u"Stopping client %s", self.name)
211
276
self.secret = None
214
if hasattr(self, "stop_initiator_tag") \
215
and self.stop_initiator_tag:
279
if getattr(self, "stop_initiator_tag", False):
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280
gobject.source_remove(self.stop_initiator_tag)
217
281
self.stop_initiator_tag = None
218
if hasattr(self, "checker_initiator_tag") \
219
and self.checker_initiator_tag:
282
if getattr(self, "checker_initiator_tag", False):
220
283
gobject.source_remove(self.checker_initiator_tag)
221
284
self.checker_initiator_tag = None
222
285
self.stop_checker()
261
324
# is as it should be.
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325
if self.checker is None:
327
# In case check_command has exactly one % operator
264
328
command = self.check_command % self.fqdn
265
329
except TypeError:
330
# Escape attributes for the shell
266
331
escaped_attrs = dict((key, re.escape(str(val)))
268
333
vars(self).iteritems())
270
335
command = self.check_command % escaped_attrs
271
336
except TypeError, error:
272
logger.critical(u'Could not format string "%s":'
273
u' %s', self.check_command, error)
337
logger.error(u'Could not format string "%s":'
338
u' %s', self.check_command, error)
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339
return True # Try again later
276
341
logger.debug(u"Starting checker %r for %s",
277
342
command, self.name)
278
self.checker = subprocess.\
280
close_fds=True, shell=True,
343
self.checker = subprocess.Popen(command,
282
346
self.checker_callback_tag = gobject.child_watch_add\
283
347
(self.checker.pid,
284
348
self.checker_callback)
301
365
#if self.checker.poll() is None:
302
366
# os.kill(self.checker.pid, signal.SIGKILL)
303
367
except OSError, error:
304
if error.errno != errno.ESRCH:
368
if error.errno != errno.ESRCH: # No such process
306
370
self.checker = None
307
def still_valid(self, now=None):
371
def still_valid(self):
308
372
"""Has the timeout not yet passed for this client?"""
310
now = datetime.datetime.now()
311
if self.last_seen is None:
373
now = datetime.datetime.now()
374
if self.last_checked_ok is None:
312
375
return now < (self.created + self.timeout)
314
return now < (self.last_seen + self.timeout)
377
return now < (self.last_checked_ok + self.timeout)
317
380
def peer_certificate(session):
370
433
def handle(self):
371
434
logger.debug(u"TCP connection from: %s",
372
435
unicode(self.client_address))
373
session = gnutls.connection.ClientSession(self.request,
436
session = gnutls.connection.ClientSession\
437
(self.request, gnutls.connection.X509Credentials())
438
# Note: gnutls.connection.X509Credentials is really a generic
439
# GnuTLS certificate credentials object so long as no X.509
440
# keys are added to it. Therefore, we can use it here despite
441
# using OpenPGP certificates.
377
443
#priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
378
444
# "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
380
priority = "SECURE256"
446
priority = "NORMAL" # Fallback default, since this
448
if self.server.settings["priority"]:
449
priority = self.server.settings["priority"]
382
450
gnutls.library.functions.gnutls_priority_set_direct\
383
451
(session._c_object, priority, None);
442
509
"""This overrides the normal server_bind() function
443
510
to bind to an interface if one was specified, and also NOT to
444
511
bind to an address or port if they were not specified."""
445
if self.options.interface:
446
if not hasattr(socket, "SO_BINDTODEVICE"):
447
# From /usr/include/asm-i486/socket.h
448
socket.SO_BINDTODEVICE = 25
512
if self.settings["interface"]:
513
# 25 is from /usr/include/asm-i486/socket.h
514
SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)
450
516
self.socket.setsockopt(socket.SOL_SOCKET,
451
socket.SO_BINDTODEVICE,
452
self.options.interface)
518
self.settings["interface"])
453
519
except socket.error, error:
454
520
if error[0] == errno.EPERM:
455
521
logger.warning(u"No permission to"
456
522
u" bind to interface %s",
457
self.options.interface)
523
self.settings["interface"])
460
526
# Only bind(2) the socket if we really need to.
507
"""Derived from the Avahi example code"""
508
global group, serviceName, serviceType, servicePort, serviceTXT, \
511
group = dbus.Interface(
512
bus.get_object( avahi.DBUS_NAME,
513
server.EntryGroupNew()),
514
avahi.DBUS_INTERFACE_ENTRY_GROUP)
515
group.connect_to_signal('StateChanged',
516
entry_group_state_changed)
517
logger.debug(u"Adding service '%s' of type '%s' ...",
518
serviceName, serviceType)
521
serviceInterface, # interface
522
avahi.PROTO_INET6, # protocol
523
dbus.UInt32(0), # flags
524
serviceName, serviceType,
526
dbus.UInt16(servicePort),
527
avahi.string_array_to_txt_array(serviceTXT))
531
def remove_service():
532
"""From the Avahi example code"""
535
if not group is None:
539
572
def server_state_changed(state):
540
573
"""Derived from the Avahi example code"""
541
574
if state == avahi.SERVER_COLLISION:
542
575
logger.warning(u"Server name collision")
544
577
elif state == avahi.SERVER_RUNNING:
548
581
def entry_group_state_changed(state, error):
549
582
"""Derived from the Avahi example code"""
550
global serviceName, server, rename_count
552
583
logger.debug(u"state change: %i", state)
554
585
if state == avahi.ENTRY_GROUP_ESTABLISHED:
555
586
logger.debug(u"Service established.")
556
587
elif state == avahi.ENTRY_GROUP_COLLISION:
558
rename_count = rename_count - 1
560
name = server.GetAlternativeServiceName(name)
561
logger.warning(u"Service name collision, "
562
u"changing name to '%s' ...", name)
567
logger.error(u"No suitable service name found after %i"
568
u" retries, exiting.", n_rename)
588
logger.warning(u"Service name collision.")
570
590
elif state == avahi.ENTRY_GROUP_FAILURE:
571
logger.error(u"Error in group state changed %s",
576
def if_nametoindex(interface):
577
"""Call the C function if_nametoindex()"""
591
logger.critical(u"Error in group state changed %s",
593
raise AvahiGroupError("State changed: %s", str(error))
595
def if_nametoindex(interface, _func=[None]):
596
"""Call the C function if_nametoindex(), or equivalent"""
597
if _func[0] is not None:
598
return _func[0](interface)
579
libc = ctypes.cdll.LoadLibrary("libc.so.6")
580
return libc.if_nametoindex(interface)
600
if "ctypes.util" not in sys.modules:
604
libc = ctypes.cdll.LoadLibrary\
605
(ctypes.util.find_library("c"))
606
_func[0] = libc.if_nametoindex
607
return _func[0](interface)
581
611
except (OSError, AttributeError):
582
612
if "struct" not in sys.modules:
584
614
if "fcntl" not in sys.modules:
586
SIOCGIFINDEX = 0x8933 # From /usr/include/linux/sockios.h
588
ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
589
struct.pack("16s16x", interface))
591
interface_index = struct.unpack("I", ifreq[16:20])[0]
592
return interface_index
616
def the_hard_way(interface):
617
"Get an interface index the hard way, i.e. using fcntl()"
618
SIOCGIFINDEX = 0x8933 # From /usr/include/linux/sockios.h
620
ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
621
struct.pack("16s16x", interface))
623
interface_index = struct.unpack("I", ifreq[16:20])[0]
624
return interface_index
625
_func[0] = the_hard_way
626
return _func[0](interface)
595
629
def daemon(nochdir, noclose):
616
def killme(status = 0):
617
logger.debug("Stopping server with exit status %d", status)
619
if main_loop_started:
628
651
global main_loop_started
629
652
main_loop_started = False
631
654
parser = OptionParser()
632
655
parser.add_option("-i", "--interface", type="string",
633
default=None, metavar="IF",
634
help="Bind to interface IF")
635
parser.add_option("-a", "--address", type="string", default=None,
656
metavar="IF", help="Bind to interface IF")
657
parser.add_option("-a", "--address", type="string",
636
658
help="Address to listen for requests on")
637
parser.add_option("-p", "--port", type="int", default=None,
659
parser.add_option("-p", "--port", type="int",
638
660
help="Port number to receive requests on")
639
parser.add_option("--timeout", type="string", # Parsed later
641
help="Amount of downtime allowed for clients")
642
parser.add_option("--interval", type="string", # Parsed later
644
help="How often to check that a client is up")
645
661
parser.add_option("--check", action="store_true", default=False,
646
662
help="Run self-test")
647
663
parser.add_option("--debug", action="store_true", default=False,
664
help="Debug mode; run in foreground and log to"
666
parser.add_option("--priority", type="string", help="GnuTLS"
667
" priority string (see GnuTLS documentation)")
668
parser.add_option("--servicename", type="string", metavar="NAME",
669
help="Zeroconf service name")
670
parser.add_option("--configdir", type="string",
671
default="/etc/mandos", metavar="DIR",
672
help="Directory to search for configuration"
649
674
(options, args) = parser.parse_args()
651
676
if options.check:
653
678
doctest.testmod()
656
# Parse the time arguments
658
options.timeout = string_to_delta(options.timeout)
660
parser.error("option --timeout: Unparseable time")
662
options.interval = string_to_delta(options.interval)
664
parser.error("option --interval: Unparseable time")
667
defaults = { "checker": "fping -q -- %%(fqdn)s" }
668
client_config = ConfigParser.SafeConfigParser(defaults)
669
#client_config.readfp(open("global.conf"), "global.conf")
670
client_config.read("mandos-clients.conf")
681
# Default values for config file for server-global settings
682
server_defaults = { "interface": "",
687
"SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
688
"servicename": "Mandos",
691
# Parse config file for server-global settings
692
server_config = ConfigParser.SafeConfigParser(server_defaults)
694
server_config.read(os.path.join(options.configdir, "server.conf"))
695
server_section = "server"
696
# Convert the SafeConfigParser object to a dict
697
server_settings = dict(server_config.items(server_section))
698
# Use getboolean on the boolean config option
699
server_settings["debug"] = server_config.getboolean\
700
(server_section, "debug")
703
# Override the settings from the config file with command line
705
for option in ("interface", "address", "port", "debug",
706
"priority", "servicename", "configdir"):
707
value = getattr(options, option)
708
if value is not None:
709
server_settings[option] = value
711
# Now we have our good server settings in "server_settings"
713
# Parse config file with clients
714
client_defaults = { "timeout": "1h",
716
"checker": "fping -q -- %%(fqdn)s",
718
client_config = ConfigParser.SafeConfigParser(client_defaults)
719
client_config.read(os.path.join(server_settings["configdir"],
723
service = AvahiService(name = server_settings["servicename"],
724
type = "_mandos._tcp", );
725
if server_settings["interface"]:
726
service.interface = if_nametoindex(server_settings["interface"])
727
783
signal.signal(signal.SIGINT, signal.SIG_IGN)
728
signal.signal(signal.SIGHUP, lambda signum, frame: killme())
729
signal.signal(signal.SIGTERM, lambda signum, frame: killme())
784
signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
785
signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())
731
787
for client in clients:
734
tcp_server = IPv6_TCPServer((options.address, options.port),
790
tcp_server = IPv6_TCPServer((server_settings["address"],
791
server_settings["port"]),
793
settings=server_settings,
738
# Find out what random port we got
740
servicePort = tcp_server.socket.getsockname()[1]
741
logger.debug(u"Now listening on port %d", servicePort)
743
if options.interface is not None:
744
global serviceInterface
745
serviceInterface = if_nametoindex(options.interface)
747
# From the Avahi example code
748
server.connect_to_signal("StateChanged", server_state_changed)
750
server_state_changed(server.GetState())
751
except dbus.exceptions.DBusException, error:
752
logger.critical(u"DBusException: %s", error)
754
# End of Avahi example code
756
gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
757
lambda *args, **kwargs:
758
tcp_server.handle_request(*args[2:],
795
# Find out what port we got
796
service.port = tcp_server.socket.getsockname()[1]
797
logger.debug(u"Now listening on address %r, port %d, flowinfo %d,"
798
u" scope_id %d" % tcp_server.socket.getsockname())
800
#service.interface = tcp_server.socket.getsockname()[3]
803
# From the Avahi example code
804
server.connect_to_signal("StateChanged", server_state_changed)
806
server_state_changed(server.GetState())
807
except dbus.exceptions.DBusException, error:
808
logger.critical(u"DBusException: %s", error)
810
# End of Avahi example code
812
gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
813
lambda *args, **kwargs:
814
tcp_server.handle_request\
815
(*args[2:], **kwargs) or True)
761
817
logger.debug("Starting main loop")
762
818
main_loop_started = True
820
except AvahiError, error:
821
logger.critical(u"AvahiError: %s" + unicode(error))
764
823
except KeyboardInterrupt:
770
827
if __name__ == '__main__':