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  • Committer: Teddy Hogeborn
  • Date: 2008-08-04 21:25:55 UTC
  • Revision ID: teddy@fukt.bsnet.se-20080804212555-rm7xxjze65f8avy3
* server.py: Cosmetic changes.

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server.py
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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
 
# methods "add" and "remove" in the "AvahiService" class, the
10
 
# "server_state_changed" and "entry_group_state_changed" functions,
11
 
# and some lines in "main".
 
9
# following functions: "AvahiService.add", "AvahiService.remove",
 
10
# "server_state_changed", "entry_group_state_changed", and some lines
 
11
# in "main".
12
12
# 
13
13
# Everything else is
14
14
# Copyright © 2007-2008 Teddy Hogeborn & Björn Påhlsson
24
24
#     GNU General Public License for more details.
25
25
# 
26
26
# You should have received a copy of the GNU General Public License
27
 
# along with this program.  If not, see
28
 
# <http://www.gnu.org/licenses/>.
 
27
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
29
28
# 
30
29
# Contact the authors at <mandos@fukt.bsnet.se>.
31
30
# 
62
61
from dbus.mainloop.glib import DBusGMainLoop
63
62
import ctypes
64
63
 
65
 
version = "1.0"
 
64
# Brief description of the operation of this program:
 
65
# 
 
66
# This server announces itself as a Zeroconf service.  Connecting
 
67
# clients use the TLS protocol, with the unusual quirk that this
 
68
# server program acts as a TLS "client" while a connecting client acts
 
69
# as a TLS "server".  The client (acting as a TLS "server") must
 
70
# supply an OpenPGP certificate, and the fingerprint of this
 
71
# certificate is used by this server to look up (in a list read from a
 
72
# file at start time) which binary blob to give the client.  No other
 
73
# authentication or authorization is done by this server.
 
74
 
66
75
 
67
76
logger = logging.Logger('mandos')
68
77
syslogger = logging.handlers.SysLogHandler\
69
 
            (facility = logging.handlers.SysLogHandler.LOG_DAEMON,
70
 
             address = "/dev/log")
 
78
            (facility = logging.handlers.SysLogHandler.LOG_DAEMON)
71
79
syslogger.setFormatter(logging.Formatter\
72
 
                        ('Mandos: %(levelname)s: %(message)s'))
 
80
                        ('%(levelname)s: %(message)s'))
73
81
logger.addHandler(syslogger)
 
82
del syslogger
74
83
 
75
 
console = logging.StreamHandler()
76
 
console.setFormatter(logging.Formatter('%(name)s: %(levelname)s:'
77
 
                                       ' %(message)s'))
78
 
logger.addHandler(console)
79
84
 
80
85
class AvahiError(Exception):
81
86
    def __init__(self, value):
108
113
    """
109
114
    def __init__(self, interface = avahi.IF_UNSPEC, name = None,
110
115
                 type = None, port = None, TXT = None, domain = "",
111
 
                 host = "", max_renames = 32768):
 
116
                 host = "", max_renames = 12):
112
117
        self.interface = interface
113
118
        self.name = name
114
119
        self.type = type
120
125
        self.domain = domain
121
126
        self.host = host
122
127
        self.rename_count = 0
123
 
        self.max_renames = max_renames
124
128
    def rename(self):
125
129
        """Derived from the Avahi example code"""
126
130
        if self.rename_count >= self.max_renames:
127
 
            logger.critical(u"No suitable Zeroconf service name found"
128
 
                            u" after %i retries, exiting.",
129
 
                            rename_count)
 
131
            logger.critical(u"No suitable service name found after %i"
 
132
                            u" retries, exiting.", rename_count)
130
133
            raise AvahiServiceError("Too many renames")
131
 
        self.name = server.GetAlternativeServiceName(self.name)
132
 
        logger.info(u"Changing Zeroconf service name to %r ...",
133
 
                    str(self.name))
134
 
        syslogger.setFormatter(logging.Formatter\
135
 
                               ('Mandos (%s): %%(levelname)s:'
136
 
                               ' %%(message)s' % self.name))
 
134
        name = server.GetAlternativeServiceName(name)
 
135
        logger.error(u"Changing name to %r ...", name)
137
136
        self.remove()
138
137
        self.add()
139
138
        self.rename_count += 1
151
150
                     avahi.DBUS_INTERFACE_ENTRY_GROUP)
152
151
            group.connect_to_signal('StateChanged',
153
152
                                    entry_group_state_changed)
154
 
        logger.debug(u"Adding Zeroconf service '%s' of type '%s' ...",
 
153
        logger.debug(u"Adding service '%s' of type '%s' ...",
155
154
                     service.name, service.type)
156
155
        group.AddService(
157
156
                self.interface,         # interface
175
174
    fingerprint: string (40 or 32 hexadecimal digits); used to
176
175
                 uniquely identify the client
177
176
    secret:    bytestring; sent verbatim (over TLS) to client
178
 
    host:      string; available for use by the checker command
 
177
    fqdn:      string (FQDN); available for use by the checker command
179
178
    created:   datetime.datetime(); object creation, not client host
180
179
    last_checked_ok: datetime.datetime() or None if not yet checked OK
181
180
    timeout:   datetime.timedelta(); How long from last_checked_ok
242
241
        else:
243
242
            raise TypeError(u"No secret or secfile for client %s"
244
243
                            % self.name)
245
 
        self.host = config.get("host", "")
 
244
        self.fqdn = config.get("fqdn", "")
246
245
        self.created = datetime.datetime.now()
247
246
        self.last_checked_ok = None
248
247
        self.timeout = string_to_delta(config["timeout"])
271
270
        The possibility that a client might be restarted is left open,
272
271
        but not currently used."""
273
272
        # If this client doesn't have a secret, it is already stopped.
274
 
        if hasattr(self, "secret") and self.secret:
 
273
        if self.secret:
275
274
            logger.info(u"Stopping client %s", self.name)
276
275
            self.secret = None
277
276
        else:
325
324
        if self.checker is None:
326
325
            try:
327
326
                # In case check_command has exactly one % operator
328
 
                command = self.check_command % self.host
 
327
                command = self.check_command % self.fqdn
329
328
            except TypeError:
330
329
                # Escape attributes for the shell
331
330
                escaped_attrs = dict((key, re.escape(str(val)))
340
339
            try:
341
340
                logger.info(u"Starting checker %r for %s",
342
341
                            command, self.name)
343
 
                # We don't need to redirect stdout and stderr, since
344
 
                # in normal mode, that is already done by daemon(),
345
 
                # and in debug mode we don't want to.  (Stdin is
346
 
                # always replaced by /dev/null.)
347
342
                self.checker = subprocess.Popen(command,
348
343
                                                close_fds=True,
349
344
                                                shell=True, cwd="/")
350
345
                self.checker_callback_tag = gobject.child_watch_add\
351
346
                                            (self.checker.pid,
352
347
                                             self.checker_callback)
353
 
            except OSError, error:
 
348
            except subprocess.OSError, error:
354
349
                logger.error(u"Failed to start subprocess: %s",
355
350
                             error)
356
351
        # Re-run this periodically if run by gobject.timeout_add
362
357
            self.checker_callback_tag = None
363
358
        if getattr(self, "checker", None) is None:
364
359
            return
365
 
        logger.debug(u"Stopping checker for %(name)s", vars(self))
 
360
        logger.debug("Stopping checker for %(name)s", vars(self))
366
361
        try:
367
362
            os.kill(self.checker.pid, signal.SIGTERM)
368
363
            #os.sleep(0.5)
413
408
    gnutls.library.functions.gnutls_openpgp_crt_import\
414
409
                    (crt, ctypes.byref(datum),
415
410
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
416
 
    # Verify the self signature in the key
417
 
    crtverify = ctypes.c_uint();
418
 
    gnutls.library.functions.gnutls_openpgp_crt_verify_self\
419
 
        (crt, 0, ctypes.byref(crtverify))
420
 
    if crtverify.value != 0:
421
 
        gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
422
 
        raise gnutls.errors.CertificateSecurityError("Verify failed")
423
411
    # New buffer for the fingerprint
424
412
    buffer = ctypes.create_string_buffer(20)
425
413
    buffer_length = ctypes.c_size_t()
551
539
                in6addr_any = "::"
552
540
                self.server_address = (in6addr_any,
553
541
                                       self.server_address[1])
554
 
            elif not self.server_address[1]:
 
542
            elif self.server_address[1] is None:
555
543
                self.server_address = (self.server_address[0],
556
544
                                       0)
557
 
#                 if self.settings["interface"]:
558
 
#                     self.server_address = (self.server_address[0],
559
 
#                                            0, # port
560
 
#                                            0, # flowinfo
561
 
#                                            if_nametoindex
562
 
#                                            (self.settings
563
 
#                                             ["interface"]))
564
545
            return super(type(self), self).server_bind()
565
546
 
566
547
 
577
558
    datetime.timedelta(1)
578
559
    >>> string_to_delta(u'1w')
579
560
    datetime.timedelta(7)
580
 
    >>> string_to_delta('5m 30s')
581
 
    datetime.timedelta(0, 330)
582
561
    """
583
 
    timevalue = datetime.timedelta(0)
584
 
    for s in interval.split():
585
 
        try:
586
 
            suffix=unicode(s[-1])
587
 
            value=int(s[:-1])
588
 
            if suffix == u"d":
589
 
                delta = datetime.timedelta(value)
590
 
            elif suffix == u"s":
591
 
                delta = datetime.timedelta(0, value)
592
 
            elif suffix == u"m":
593
 
                delta = datetime.timedelta(0, 0, 0, 0, value)
594
 
            elif suffix == u"h":
595
 
                delta = datetime.timedelta(0, 0, 0, 0, 0, value)
596
 
            elif suffix == u"w":
597
 
                delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
598
 
            else:
599
 
                raise ValueError
600
 
        except (ValueError, IndexError):
 
562
    try:
 
563
        suffix=unicode(interval[-1])
 
564
        value=int(interval[:-1])
 
565
        if suffix == u"d":
 
566
            delta = datetime.timedelta(value)
 
567
        elif suffix == u"s":
 
568
            delta = datetime.timedelta(0, value)
 
569
        elif suffix == u"m":
 
570
            delta = datetime.timedelta(0, 0, 0, 0, value)
 
571
        elif suffix == u"h":
 
572
            delta = datetime.timedelta(0, 0, 0, 0, 0, value)
 
573
        elif suffix == u"w":
 
574
            delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
 
575
        else:
601
576
            raise ValueError
602
 
        timevalue += delta
603
 
    return timevalue
 
577
    except (ValueError, IndexError):
 
578
        raise ValueError
 
579
    return delta
604
580
 
605
581
 
606
582
def server_state_changed(state):
607
583
    """Derived from the Avahi example code"""
608
584
    if state == avahi.SERVER_COLLISION:
609
 
        logger.error(u"Zeroconf server name collision")
 
585
        logger.error(u"Server name collision")
610
586
        service.remove()
611
587
    elif state == avahi.SERVER_RUNNING:
612
588
        service.add()
614
590
 
615
591
def entry_group_state_changed(state, error):
616
592
    """Derived from the Avahi example code"""
617
 
    logger.debug(u"Avahi state change: %i", state)
 
593
    logger.debug(u"state change: %i", state)
618
594
    
619
595
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
620
 
        logger.debug(u"Zeroconf service established.")
 
596
        logger.debug(u"Service established.")
621
597
    elif state == avahi.ENTRY_GROUP_COLLISION:
622
 
        logger.warning(u"Zeroconf service name collision.")
 
598
        logger.warning(u"Service name collision.")
623
599
        service.rename()
624
600
    elif state == avahi.ENTRY_GROUP_FAILURE:
625
 
        logger.critical(u"Avahi: Error in group state changed %s",
 
601
        logger.critical(u"Error in group state changed %s",
626
602
                        unicode(error))
627
603
        raise AvahiGroupError("State changed: %s", str(error))
628
604
 
651
627
    return if_nametoindex(interface)
652
628
 
653
629
 
654
 
def daemon(nochdir = False, noclose = False):
 
630
def daemon(nochdir, noclose):
655
631
    """See daemon(3).  Standard BSD Unix function.
656
632
    This should really exist as os.daemon, but it doesn't (yet)."""
657
633
    if os.fork():
659
635
    os.setsid()
660
636
    if not nochdir:
661
637
        os.chdir("/")
662
 
    if os.fork():
663
 
        sys.exit()
664
638
    if not noclose:
665
639
        # Close all standard open file descriptors
666
640
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
678
652
    global main_loop_started
679
653
    main_loop_started = False
680
654
    
681
 
    parser = OptionParser(version = "%%prog %s" % version)
 
655
    parser = OptionParser()
682
656
    parser.add_option("-i", "--interface", type="string",
683
657
                      metavar="IF", help="Bind to interface IF")
684
658
    parser.add_option("-a", "--address", type="string",
687
661
                      help="Port number to receive requests on")
688
662
    parser.add_option("--check", action="store_true", default=False,
689
663
                      help="Run self-test")
690
 
    parser.add_option("--debug", action="store_true",
 
664
    parser.add_option("--debug", action="store_true", default=False,
691
665
                      help="Debug mode; run in foreground and log to"
692
666
                      " terminal")
693
667
    parser.add_option("--priority", type="string", help="GnuTLS"
718
692
    # Parse config file for server-global settings
719
693
    server_config = ConfigParser.SafeConfigParser(server_defaults)
720
694
    del server_defaults
721
 
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
 
695
    server_config.read(os.path.join(options.configdir, "server.conf"))
 
696
    server_section = "server"
722
697
    # Convert the SafeConfigParser object to a dict
723
 
    server_settings = server_config.defaults()
 
698
    server_settings = dict(server_config.items(server_section))
724
699
    # Use getboolean on the boolean config option
725
700
    server_settings["debug"] = server_config.getboolean\
726
 
                               ("DEFAULT", "debug")
 
701
                               (server_section, "debug")
727
702
    del server_config
728
703
    
729
704
    # Override the settings from the config file with command line
736
711
    del options
737
712
    # Now we have our good server settings in "server_settings"
738
713
    
739
 
    debug = server_settings["debug"]
740
 
    
741
 
    if not debug:
742
 
        syslogger.setLevel(logging.WARNING)
743
 
        console.setLevel(logging.WARNING)
744
 
    
745
 
    if server_settings["servicename"] != "Mandos":
746
 
        syslogger.setFormatter(logging.Formatter\
747
 
                               ('Mandos (%s): %%(levelname)s:'
748
 
                                ' %%(message)s'
749
 
                                % server_settings["servicename"]))
750
 
    
751
714
    # Parse config file with clients
752
715
    client_defaults = { "timeout": "1h",
753
716
                        "interval": "5m",
754
 
                        "checker": "fping -q -- %(host)s",
755
 
                        "host": "",
 
717
                        "checker": "fping -q -- %%(fqdn)s",
756
718
                        }
757
719
    client_config = ConfigParser.SafeConfigParser(client_defaults)
758
720
    client_config.read(os.path.join(server_settings["configdir"],
762
724
    service = AvahiService(name = server_settings["servicename"],
763
725
                           type = "_mandos._tcp", );
764
726
    if server_settings["interface"]:
765
 
        service.interface = if_nametoindex\
766
 
                            (server_settings["interface"])
 
727
        service.interface = if_nametoindex(server_settings["interface"])
767
728
    
768
729
    global main_loop
769
730
    global bus
772
733
    DBusGMainLoop(set_as_default=True )
773
734
    main_loop = gobject.MainLoop()
774
735
    bus = dbus.SystemBus()
775
 
    server = dbus.Interface(bus.get_object(avahi.DBUS_NAME,
776
 
                                           avahi.DBUS_PATH_SERVER),
777
 
                            avahi.DBUS_INTERFACE_SERVER)
 
736
    server = dbus.Interface(
 
737
            bus.get_object( avahi.DBUS_NAME, avahi.DBUS_PATH_SERVER ),
 
738
            avahi.DBUS_INTERFACE_SERVER )
778
739
    # End of Avahi example code
779
740
    
 
741
    debug = server_settings["debug"]
 
742
    
 
743
    if debug:
 
744
        console = logging.StreamHandler()
 
745
        # console.setLevel(logging.DEBUG)
 
746
        console.setFormatter(logging.Formatter\
 
747
                             ('%(levelname)s: %(message)s'))
 
748
        logger.addHandler(console)
 
749
        del console
 
750
    
780
751
    clients = Set()
781
752
    def remove_from_clients(client):
782
753
        clients.remove(client)
789
760
                              config
790
761
                              = dict(client_config.items(section)))
791
762
                       for section in client_config.sections()))
792
 
    if not clients:
793
 
        logger.critical(u"No clients defined")
794
 
        sys.exit(1)
795
 
    
796
 
    if debug:
797
 
        # Redirect stdin so all checkers get /dev/null
798
 
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
799
 
        os.dup2(null, sys.stdin.fileno())
800
 
        if null > 2:
801
 
            os.close(null)
802
 
    else:
803
 
        # No console logging
804
 
        logger.removeHandler(console)
805
 
        # Close all input and output, do double fork, etc.
806
 
        daemon()
807
 
    
808
 
    pidfilename = "/var/run/mandos/mandos.pid"
809
 
    pid = os.getpid()
810
 
    try:
811
 
        pidfile = open(pidfilename, "w")
812
 
        pidfile.write(str(pid) + "\n")
813
 
        pidfile.close()
814
 
        del pidfile
815
 
    except IOError, err:
816
 
        logger.error(u"Could not write %s file with PID %d",
817
 
                     pidfilename, os.getpid())
 
763
    
 
764
    if not debug:
 
765
        daemon(False, False)
818
766
    
819
767
    def cleanup():
820
768
        "Cleanup function; run on exit"
867
815
                             tcp_server.handle_request\
868
816
                             (*args[2:], **kwargs) or True)
869
817
        
870
 
        logger.debug(u"Starting main loop")
 
818
        logger.debug("Starting main loop")
871
819
        main_loop_started = True
872
820
        main_loop.run()
873
821
    except AvahiError, error: