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: "AvahiService.add", "AvahiService.remove",
9
# following functions: "add_service", "remove_service",
10
10
# "server_state_changed", "entry_group_state_changed", and some lines
14
# Copyright © 2007-2008 Teddy Hogeborn & Björn Påhlsson
13
# Everything else is Copyright © 2007-2008 Teddy Hogeborn and Björn
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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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logger.addHandler(syslogger)
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.
102
name = string; Example: "Mandos"
103
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
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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
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max_renames = integer; maximum number of renames
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rename_count = integer; counter so we only rename after collisions
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a sensible number of times
114
def __init__(self, interface = avahi.IF_UNSPEC, name = None,
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type = None, port = None, TXT = None, domain = "",
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host = "", max_renames = 12):
117
"""An Avahi (Zeroconf) service. """
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self.interface = interface
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self.rename_count = 0
130
"""Derived from the Avahi example code"""
131
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,
150
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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# This variable is used to optionally bind to a specified interface.
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# It is a global variable to fit in with the other variables from the
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serviceInterface = avahi.IF_UNSPEC
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89
# From the Avahi example code:
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group = None # our entry group
90
serviceName = "Mandos"
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serviceType = "_mandos._tcp" # http://www.dns-sd.org/ServiceTypes.html
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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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99
# End of Avahi example code
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107
uniquely identify the client
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secret: bytestring; sent verbatim (over TLS) to client
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fqdn: string (FQDN); available for use by the checker command
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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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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
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interval: datetime.timedelta(); How often to start a new checker
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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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'None' if no process is running.
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Is 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. %() expansions are done at
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client lives. %()s expansions are done at
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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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Private attibutes:
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_timeout: Real variable for 'timeout'
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128
_interval: Real variable for 'interval'
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_timeout_milliseconds: Used when calling gobject.timeout_add()
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_timeout_milliseconds: Used by gobject.timeout_add()
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_interval_milliseconds: - '' -
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132
def _set_timeout(self, timeout):
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152
interval = property(lambda self: self._interval,
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154
del _set_interval
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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):
155
def __init__(self, name=None, options=None, stop_hook=None,
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fingerprint=None, secret=None, secfile=None,
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fqdn=None, timeout=None, interval=-1, checker=None):
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158
"""Note: the 'checker' argument sets the 'checker_command'
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159
attribute and not the 'checker' attribute.."""
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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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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()
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raise TypeError(u"No secret or secfile for client %s"
172
raise RuntimeError(u"No secret or secfile for client %s"
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self.fqdn = fqdn # string
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self.created = datetime.datetime.now()
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self.last_checked_ok = None
248
self.timeout = string_to_delta(timeout)
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self.interval = string_to_delta(interval)
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)
250
185
self.stop_hook = stop_hook
251
186
self.checker = None
252
187
self.checker_initiator_tag = None
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"""Stop this client.
271
The possibility that a client might be restarted is left open,
272
but not currently used."""
206
The possibility that this client might be restarted is left
207
open, 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)
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211
self.secret = None
279
if getattr(self, "stop_initiator_tag", False):
214
if hasattr(self, "stop_initiator_tag") \
215
and self.stop_initiator_tag:
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gobject.source_remove(self.stop_initiator_tag)
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self.stop_initiator_tag = None
282
if getattr(self, "checker_initiator_tag", False):
218
if hasattr(self, "checker_initiator_tag") \
219
and self.checker_initiator_tag:
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220
gobject.source_remove(self.checker_initiator_tag)
284
221
self.checker_initiator_tag = None
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self.stop_checker()
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# is as it should be.
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if self.checker is None:
327
# In case check_command has exactly one % operator
328
264
command = self.check_command % self.fqdn
329
265
except TypeError:
330
# Escape attributes for the shell
331
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escaped_attrs = dict((key, re.escape(str(val)))
333
268
vars(self).iteritems())
335
270
command = self.check_command % escaped_attrs
336
271
except TypeError, error:
337
logger.error(u'Could not format string "%s":'
338
u' %s', self.check_command, error)
272
logger.critical(u'Could not format string "%s":'
273
u' %s', self.check_command, error)
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return True # Try again later
341
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logger.debug(u"Starting checker %r for %s",
342
277
command, self.name)
343
self.checker = subprocess.Popen(command,
278
self.checker = subprocess.\
280
close_fds=True, shell=True,
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self.checker_callback_tag = gobject.child_watch_add\
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283
(self.checker.pid,
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284
self.checker_callback)
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#if self.checker.poll() is None:
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# os.kill(self.checker.pid, signal.SIGKILL)
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303
except OSError, error:
368
if error.errno != errno.ESRCH: # No such process
304
if error.errno != errno.ESRCH:
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self.checker = None
371
def still_valid(self):
307
def still_valid(self, now=None):
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"""Has the timeout not yet passed for this client?"""
373
now = datetime.datetime.now()
374
if self.last_checked_ok is None:
310
now = datetime.datetime.now()
311
if self.last_seen is None:
375
312
return now < (self.created + self.timeout)
377
return now < (self.last_checked_ok + self.timeout)
314
return now < (self.last_seen + self.timeout)
380
317
def peer_certificate(session):
433
370
def handle(self):
434
371
logger.debug(u"TCP connection from: %s",
435
372
unicode(self.client_address))
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.
373
session = gnutls.connection.ClientSession(self.request,
443
377
#priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
444
378
# "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
446
priority = "NORMAL" # Fallback default, since this
448
if self.server.settings["priority"]:
449
priority = self.server.settings["priority"]
380
priority = "SECURE256"
450
382
gnutls.library.functions.gnutls_priority_set_direct\
451
383
(session._c_object, priority, None);
509
442
"""This overrides the normal server_bind() function
510
443
to bind to an interface if one was specified, and also NOT to
511
444
bind to an address or port if they were not specified."""
512
if self.settings["interface"]:
513
# 25 is from /usr/include/asm-i486/socket.h
514
SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)
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
516
450
self.socket.setsockopt(socket.SOL_SOCKET,
518
self.settings["interface"])
451
socket.SO_BINDTODEVICE,
452
self.options.interface)
519
453
except socket.error, error:
520
454
if error[0] == errno.EPERM:
521
455
logger.warning(u"No permission to"
522
456
u" bind to interface %s",
523
self.settings["interface"])
457
self.options.interface)
526
460
# 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:
572
539
def server_state_changed(state):
573
540
"""Derived from the Avahi example code"""
574
541
if state == avahi.SERVER_COLLISION:
575
542
logger.warning(u"Server name collision")
577
544
elif state == avahi.SERVER_RUNNING:
581
548
def entry_group_state_changed(state, error):
582
549
"""Derived from the Avahi example code"""
550
global serviceName, server, rename_count
583
552
logger.debug(u"state change: %i", state)
585
554
if state == avahi.ENTRY_GROUP_ESTABLISHED:
586
555
logger.debug(u"Service established.")
587
556
elif state == avahi.ENTRY_GROUP_COLLISION:
588
logger.warning(u"Service name 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)
590
570
elif state == avahi.ENTRY_GROUP_FAILURE:
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)
571
logger.error(u"Error in group state changed %s",
576
def if_nametoindex(interface):
577
"""Call the C function if_nametoindex()"""
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)
579
libc = ctypes.cdll.LoadLibrary("libc.so.6")
580
return libc.if_nametoindex(interface)
611
581
except (OSError, AttributeError):
612
582
if "struct" not in sys.modules:
614
584
if "fcntl" not in sys.modules:
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)
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
629
595
def daemon(nochdir, noclose):
616
def killme(status = 0):
617
logger.debug("Stopping server with exit status %d", status)
619
if main_loop_started:
651
628
global main_loop_started
652
629
main_loop_started = False
654
631
parser = OptionParser()
655
632
parser.add_option("-i", "--interface", type="string",
656
metavar="IF", help="Bind to interface IF")
657
parser.add_option("-a", "--address", type="string",
633
default=None, metavar="IF",
634
help="Bind to interface IF")
635
parser.add_option("-a", "--address", type="string", default=None,
658
636
help="Address to listen for requests on")
659
parser.add_option("-p", "--port", type="int",
637
parser.add_option("-p", "--port", type="int", default=None,
660
638
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")
661
645
parser.add_option("--check", action="store_true", default=False,
662
646
help="Run self-test")
663
647
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"
674
649
(options, args) = parser.parse_args()
676
651
if options.check:
678
653
doctest.testmod()
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"])
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")
783
727
signal.signal(signal.SIGINT, signal.SIG_IGN)
784
signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
785
signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())
728
signal.signal(signal.SIGHUP, lambda signum, frame: killme())
729
signal.signal(signal.SIGTERM, lambda signum, frame: killme())
787
731
for client in clients:
790
tcp_server = IPv6_TCPServer((server_settings["address"],
791
server_settings["port"]),
734
tcp_server = IPv6_TCPServer((options.address, options.port),
793
settings=server_settings,
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)
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:],
817
761
logger.debug("Starting main loop")
818
762
main_loop_started = True
820
except AvahiError, error:
821
logger.critical(u"AvahiError: %s" + unicode(error))
823
764
except KeyboardInterrupt:
827
770
if __name__ == '__main__':