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# This program is partly derived from an example program for an Avahi
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# service publisher, downloaded from
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# <http://avahi.org/wiki/PythonPublishExample>. This includes the
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# following functions: "add_service", "remove_service",
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# following functions: "AvahiService.add", "AvahiService.remove",
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# "server_state_changed", "entry_group_state_changed", and some lines
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# Everything else is Copyright © 2007-2008 Teddy Hogeborn and Björn
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# Copyright © 2007-2008 Teddy Hogeborn & Björn Påhlsson
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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logger.addHandler(syslogger)
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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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class AvahiError(Exception):
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def __init__(self, value):
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return repr(self.value)
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class AvahiServiceError(AvahiError):
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class AvahiGroupError(AvahiError):
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class AvahiService(object):
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interface: integer; avahi.IF_UNSPEC or an interface index.
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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
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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
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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):
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"""An Avahi (Zeroconf) service. """
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self.interface = interface
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self.rename_count = 0
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"""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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# From the Avahi example code:
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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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group = None # our entry group
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# End of Avahi example code
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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()
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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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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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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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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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_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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def _set_timeout(self, timeout):
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"""Stop this client.
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The possibility that this client might be restarted is left
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open, but not currently used."""
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The possibility that a client might be restarted is left open,
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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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self.secret = None
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if hasattr(self, "stop_initiator_tag") \
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and self.stop_initiator_tag:
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if getattr(self, "stop_initiator_tag", False):
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gobject.source_remove(self.stop_initiator_tag)
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self.stop_initiator_tag = None
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if hasattr(self, "checker_initiator_tag") \
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and self.checker_initiator_tag:
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if getattr(self, "checker_initiator_tag", False):
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gobject.source_remove(self.checker_initiator_tag)
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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:
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# In case check_command has exactly one % operator
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command = self.check_command % self.fqdn
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except TypeError:
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# Escape attributes for the shell
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escaped_attrs = dict((key, re.escape(str(val)))
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vars(self).iteritems())
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command = self.check_command % escaped_attrs
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except TypeError, error:
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logger.critical(u'Could not format string "%s":'
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u' %s', self.check_command, error)
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logger.error(u'Could not format string "%s":'
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u' %s', self.check_command, error)
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return True # Try again later
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logger.debug(u"Starting checker %r for %s",
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command, self.name)
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self.checker = subprocess.\
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close_fds=True, shell=True,
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self.checker = subprocess.Popen(command,
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self.checker_callback_tag = gobject.child_watch_add\
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(self.checker.pid,
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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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except OSError, error:
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if error.errno != errno.ESRCH:
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if error.errno != errno.ESRCH: # No such process
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self.checker = None
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def still_valid(self, now=None):
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def still_valid(self):
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"""Has the timeout not yet passed for this client?"""
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now = datetime.datetime.now()
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if self.last_seen is None:
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now = datetime.datetime.now()
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if self.last_checked_ok is None:
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return now < (self.created + self.timeout)
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return now < (self.last_seen + self.timeout)
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return now < (self.last_checked_ok + self.timeout)
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def peer_certificate(session):
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def handle(self):
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logger.debug(u"TCP connection from: %s",
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unicode(self.client_address))
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session = gnutls.connection.ClientSession(self.request,
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session = gnutls.connection.ClientSession\
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(self.request, gnutls.connection.X509Credentials())
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# Note: gnutls.connection.X509Credentials is really a generic
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# GnuTLS certificate credentials object so long as no X.509
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# keys are added to it. Therefore, we can use it here despite
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# using OpenPGP certificates.
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#priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
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# "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
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if self.server.options.priority:
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priority = self.server.options.priority
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priority = "NORMAL" # Fallback default, since this
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if self.server.settings["priority"]:
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priority = self.server.settings["priority"]
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gnutls.library.functions.gnutls_priority_set_direct\
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(session._c_object, priority, None);
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"""This overrides the normal server_bind() function
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to bind to an interface if one was specified, and also NOT to
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bind to an address or port if they were not specified."""
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if self.options.interface:
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if not hasattr(socket, "SO_BINDTODEVICE"):
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# From /usr/include/asm-i486/socket.h
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socket.SO_BINDTODEVICE = 25
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if self.settings["interface"] != avahi.IF_UNSPEC:
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# 25 is from /usr/include/asm-i486/socket.h
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SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)
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self.socket.setsockopt(socket.SOL_SOCKET,
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socket.SO_BINDTODEVICE,
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self.options.interface)
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self.settings["interface"])
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except socket.error, error:
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if error[0] == errno.EPERM:
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logger.warning(u"No permission to"
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u" bind to interface %s",
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self.options.interface)
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self.settings["interface"])
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# Only bind(2) the socket if we really need to.
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"""Derived from the Avahi example code"""
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global group, serviceName, serviceType, servicePort, serviceTXT, \
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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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serviceName, serviceType)
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serviceInterface, # interface
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avahi.PROTO_INET6, # protocol
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dbus.UInt32(0), # flags
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serviceName, serviceType,
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dbus.UInt16(servicePort),
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avahi.string_array_to_txt_array(serviceTXT))
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def remove_service():
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"""From the Avahi example code"""
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if not group is None:
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def server_state_changed(state):
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"""Derived from the Avahi example code"""
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if state == avahi.SERVER_COLLISION:
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logger.warning(u"Server name collision")
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elif state == avahi.SERVER_RUNNING:
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def entry_group_state_changed(state, error):
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"""Derived from the Avahi example code"""
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global serviceName, server, rename_count
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logger.debug(u"state change: %i", state)
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if state == avahi.ENTRY_GROUP_ESTABLISHED:
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logger.debug(u"Service established.")
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elif state == avahi.ENTRY_GROUP_COLLISION:
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rename_count = rename_count - 1
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name = server.GetAlternativeServiceName(name)
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logger.warning(u"Service name collision, "
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u"changing name to '%s' ...", name)
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logger.error(u"No suitable service name found after %i"
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u" retries, exiting.", n_rename)
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logger.warning(u"Service name collision.")
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elif state == avahi.ENTRY_GROUP_FAILURE:
568
logger.error(u"Error in group state changed %s",
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def if_nametoindex(interface):
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"""Call the C function if_nametoindex()"""
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logger.critical(u"Error in group state changed %s",
593
raise AvahiGroupError("State changed: %s", str(error))
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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)
576
libc = ctypes.cdll.LoadLibrary("libc.so.6")
577
return libc.if_nametoindex(interface)
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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)
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611
except (OSError, AttributeError):
579
612
if "struct" not in sys.modules:
581
614
if "fcntl" not in sys.modules:
583
SIOCGIFINDEX = 0x8933 # From /usr/include/linux/sockios.h
585
ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
586
struct.pack("16s16x", interface))
588
interface_index = struct.unpack("I", ifreq[16:20])[0]
589
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)
592
629
def daemon(nochdir, noclose):
613
def killme(status = 0):
614
logger.debug("Stopping server with exit status %d", status)
616
if main_loop_started:
625
651
global main_loop_started
626
652
main_loop_started = False
628
654
parser = OptionParser()
629
655
parser.add_option("-i", "--interface", type="string",
630
default=None, metavar="IF",
631
help="Bind to interface IF")
632
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",
633
658
help="Address to listen for requests on")
634
parser.add_option("-p", "--port", type="int", default=None,
659
parser.add_option("-p", "--port", type="int",
635
660
help="Port number to receive requests on")
636
661
parser.add_option("--check", action="store_true", default=False,
637
662
help="Run self-test")
638
663
parser.add_option("--debug", action="store_true", default=False,
640
parser.add_option("--priority", type="string",
642
help="GnuTLS priority string"
643
" (see GnuTLS documentation)")
644
parser.add_option("--servicename", type="string",
645
default="Mandos", help="Zeroconf service name")
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"
646
674
(options, args) = parser.parse_args()
648
676
if options.check:
650
678
doctest.testmod()
654
defaults = { "timeout": "1h",
656
"checker": "fping -q -- %%(fqdn)s",
658
client_config = ConfigParser.SafeConfigParser(defaults)
659
#client_config.readfp(open("global.conf"), "global.conf")
660
client_config.read("mandos-clients.conf")
663
serviceName = options.servicename;
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")
702
if not server_settings["interface"]:
703
server_settings["interface"] = avahi.IF_UNSPEC
705
# Override the settings from the config file with command line
707
for option in ("interface", "address", "port", "debug",
708
"priority", "servicename", "configdir"):
709
value = getattr(options, option)
710
if value is not None:
711
server_settings[option] = value
713
# Now we have our good server settings in "server_settings"
715
# Parse config file with clients
716
client_defaults = { "timeout": "1h",
718
"checker": "fping -q -- %%(fqdn)s",
720
client_config = ConfigParser.SafeConfigParser(client_defaults)
721
client_config.read(os.path.join(server_settings["configdir"],
725
service = AvahiService(name = server_settings["servicename"],
726
type = "_mandos._tcp", );
720
783
signal.signal(signal.SIGINT, signal.SIG_IGN)
721
signal.signal(signal.SIGHUP, lambda signum, frame: killme())
722
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())
724
787
for client in clients:
727
tcp_server = IPv6_TCPServer((options.address, options.port),
790
tcp_server = IPv6_TCPServer((server_settings["address"],
791
server_settings["port"]),
793
settings=server_settings,
731
# Find out what random port we got
733
servicePort = tcp_server.socket.getsockname()[1]
734
logger.debug(u"Now listening on port %d", servicePort)
736
if options.interface is not None:
737
global serviceInterface
738
serviceInterface = if_nametoindex(options.interface)
740
# From the Avahi example code
741
server.connect_to_signal("StateChanged", server_state_changed)
743
server_state_changed(server.GetState())
744
except dbus.exceptions.DBusException, error:
745
logger.critical(u"DBusException: %s", error)
747
# End of Avahi example code
749
gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
750
lambda *args, **kwargs:
751
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 port %d", service.port)
799
if not server_settings["interface"]:
800
service.interface = if_nametoindex\
801
(server_settings["interface"])
804
# From the Avahi example code
805
server.connect_to_signal("StateChanged", server_state_changed)
807
server_state_changed(server.GetState())
808
except dbus.exceptions.DBusException, error:
809
logger.critical(u"DBusException: %s", error)
811
# End of Avahi example code
813
gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
814
lambda *args, **kwargs:
815
tcp_server.handle_request\
816
(*args[2:], **kwargs) or True)
754
818
logger.debug("Starting main loop")
755
819
main_loop_started = True
821
except AvahiError, error:
822
logger.critical(u"AvahiError: %s" + unicode(error))
757
824
except KeyboardInterrupt:
763
828
if __name__ == '__main__':