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  • Committer: Teddy Hogeborn
  • Date: 2008-07-21 04:42:08 UTC
  • mfrom: (15.1.3 mandos)
  • Revision ID: teddy@fukt.bsnet.se-20080721044208-y8v1sjmvalfiehrv
Merge.

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# This program is partly derived from an example program for an Avahi
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# 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: "add_service", "remove_service",
 
10
# "server_state_changed", "entry_group_state_changed", and some lines
 
11
# in "main".
12
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13
 
# Everything else is
14
 
# Copyright © 2008 Teddy Hogeborn & Björn Påhlsson
 
13
# Everything else is Copyright © 2007-2008 Teddy Hogeborn and Björn
 
14
# Påhlsson.
15
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# This program is free software: you can redistribute it and/or modify
17
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# it under the terms of the GNU General Public License as published by
24
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#     GNU General Public License for more details.
25
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# 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
 
# Contact the authors at <mandos@fukt.bsnet.se>.
 
29
# Contact the authors at <https://www.fukt.bsnet.se/~belorn/> and
 
30
# <https://www.fukt.bsnet.se/~teddy/>.
31
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33
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from __future__ import division
34
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35
35
import SocketServer
36
36
import socket
 
37
import select
37
38
from optparse import OptionParser
38
39
import datetime
39
40
import errno
54
55
import stat
55
56
import logging
56
57
import logging.handlers
57
 
import pwd
58
58
 
59
59
import dbus
60
60
import gobject
61
61
import avahi
62
62
from dbus.mainloop.glib import DBusGMainLoop
63
63
import ctypes
64
 
import ctypes.util
65
 
 
66
 
version = "1.0"
 
64
 
 
65
# Brief description of the operation of this program:
 
66
 
67
# This server announces itself as a Zeroconf service.  Connecting
 
68
# clients use the TLS protocol, with the unusual quirk that this
 
69
# server program acts as a TLS "client" while the connecting clients
 
70
# acts as a TLS "server".  The clients (acting as a TLS "server") must
 
71
# supply an OpenPGP certificate, and the fingerprint of this
 
72
# certificate is used by this server to look up (in a list read from a
 
73
# file at start time) which binary blob to give the client.  No other
 
74
# authentication or authorization is done by this server.
 
75
 
67
76
 
68
77
logger = logging.Logger('mandos')
69
78
syslogger = logging.handlers.SysLogHandler\
70
 
            (facility = logging.handlers.SysLogHandler.LOG_DAEMON,
71
 
             address = "/dev/log")
 
79
            (facility = logging.handlers.SysLogHandler.LOG_DAEMON)
72
80
syslogger.setFormatter(logging.Formatter\
73
 
                        ('Mandos: %(levelname)s: %(message)s'))
 
81
                        ('%(levelname)s: %(message)s'))
74
82
logger.addHandler(syslogger)
75
 
 
76
 
console = logging.StreamHandler()
77
 
console.setFormatter(logging.Formatter('%(name)s: %(levelname)s:'
78
 
                                       ' %(message)s'))
79
 
logger.addHandler(console)
80
 
 
81
 
class AvahiError(Exception):
82
 
    def __init__(self, value):
83
 
        self.value = value
84
 
        super(AvahiError, self).__init__()
85
 
    def __str__(self):
86
 
        return repr(self.value)
87
 
 
88
 
class AvahiServiceError(AvahiError):
89
 
    pass
90
 
 
91
 
class AvahiGroupError(AvahiError):
92
 
    pass
93
 
 
94
 
 
95
 
class AvahiService(object):
96
 
    """An Avahi (Zeroconf) service.
97
 
    Attributes:
98
 
    interface: integer; avahi.IF_UNSPEC or an interface index.
99
 
               Used to optionally bind to the specified interface.
100
 
    name: string; Example: 'Mandos'
101
 
    type: string; Example: '_mandos._tcp'.
102
 
                  See <http://www.dns-sd.org/ServiceTypes.html>
103
 
    port: integer; what port to announce
104
 
    TXT: list of strings; TXT record for the service
105
 
    domain: string; Domain to publish on, default to .local if empty.
106
 
    host: string; Host to publish records for, default is localhost
107
 
    max_renames: integer; maximum number of renames
108
 
    rename_count: integer; counter so we only rename after collisions
109
 
                  a sensible number of times
110
 
    """
111
 
    def __init__(self, interface = avahi.IF_UNSPEC, name = None,
112
 
                 servicetype = None, port = None, TXT = None, domain = "",
113
 
                 host = "", max_renames = 32768):
114
 
        self.interface = interface
115
 
        self.name = name
116
 
        self.type = servicetype
117
 
        self.port = port
118
 
        if TXT is None:
119
 
            self.TXT = []
120
 
        else:
121
 
            self.TXT = TXT
122
 
        self.domain = domain
123
 
        self.host = host
124
 
        self.rename_count = 0
125
 
        self.max_renames = max_renames
126
 
    def rename(self):
127
 
        """Derived from the Avahi example code"""
128
 
        if self.rename_count >= self.max_renames:
129
 
            logger.critical(u"No suitable Zeroconf service name found"
130
 
                            u" after %i retries, exiting.",
131
 
                            self.rename_count)
132
 
            raise AvahiServiceError("Too many renames")
133
 
        self.name = server.GetAlternativeServiceName(self.name)
134
 
        logger.info(u"Changing Zeroconf service name to %r ...",
135
 
                    str(self.name))
136
 
        syslogger.setFormatter(logging.Formatter\
137
 
                               ('Mandos (%s): %%(levelname)s:'
138
 
                               ' %%(message)s' % self.name))
139
 
        self.remove()
140
 
        self.add()
141
 
        self.rename_count += 1
142
 
    def remove(self):
143
 
        """Derived from the Avahi example code"""
144
 
        if group is not None:
145
 
            group.Reset()
146
 
    def add(self):
147
 
        """Derived from the Avahi example code"""
148
 
        global group
149
 
        if group is None:
150
 
            group = dbus.Interface\
151
 
                    (bus.get_object(avahi.DBUS_NAME,
152
 
                                    server.EntryGroupNew()),
153
 
                     avahi.DBUS_INTERFACE_ENTRY_GROUP)
154
 
            group.connect_to_signal('StateChanged',
155
 
                                    entry_group_state_changed)
156
 
        logger.debug(u"Adding Zeroconf service '%s' of type '%s' ...",
157
 
                     service.name, service.type)
158
 
        group.AddService(
159
 
                self.interface,         # interface
160
 
                avahi.PROTO_INET6,      # protocol
161
 
                dbus.UInt32(0),         # flags
162
 
                self.name, self.type,
163
 
                self.domain, self.host,
164
 
                dbus.UInt16(self.port),
165
 
                avahi.string_array_to_txt_array(self.TXT))
166
 
        group.Commit()
167
 
 
 
83
del syslogger
 
84
 
 
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
 
87
# Avahi example code.
 
88
serviceInterface = avahi.IF_UNSPEC
168
89
# From the Avahi example code:
169
 
group = None                            # our entry group
 
90
serviceName = "Mandos"
 
91
serviceType = "_mandos._tcp" # http://www.dns-sd.org/ServiceTypes.html
 
92
servicePort = None                      # Not known at startup
 
93
serviceTXT = []                         # TXT record for the service
 
94
domain = ""                  # Domain to publish on, default to .local
 
95
host = ""          # Host to publish records for, default to localhost
 
96
group = None #our entry group
 
97
rename_count = 12       # Counter so we only rename after collisions a
 
98
                        # sensible number of times
170
99
# End of Avahi example code
171
100
 
172
101
 
177
106
    fingerprint: string (40 or 32 hexadecimal digits); used to
178
107
                 uniquely identify the client
179
108
    secret:    bytestring; sent verbatim (over TLS) to client
180
 
    host:      string; available for use by the checker command
181
 
    created:   datetime.datetime(); object creation, not client host
182
 
    last_checked_ok: datetime.datetime() or None if not yet checked OK
183
 
    timeout:   datetime.timedelta(); How long from last_checked_ok
184
 
                                     until this client is invalid
 
109
    fqdn:      string (FQDN); available for use by the checker command
 
110
    created:   datetime.datetime()
 
111
    last_seen: datetime.datetime() or None if not yet seen
 
112
    timeout:   datetime.timedelta(); How long from last_seen until
 
113
                                     this client is invalid
185
114
    interval:  datetime.timedelta(); How often to start a new checker
186
115
    stop_hook: If set, called by stop() as stop_hook(self)
187
116
    checker:   subprocess.Popen(); a running checker process used
188
117
                                   to see if the client lives.
189
 
                                   'None' if no process is running.
 
118
                                   Is None if no process is running.
190
119
    checker_initiator_tag: a gobject event source tag, or None
191
120
    stop_initiator_tag:    - '' -
192
121
    checker_callback_tag:  - '' -
193
122
    checker_command: string; External command which is run to check if
194
 
                     client lives.  %() expansions are done at
 
123
                     client lives.  %()s expansions are done at
195
124
                     runtime with vars(self) as dict, so that for
196
125
                     instance %(name)s can be used in the command.
197
126
    Private attibutes:
198
127
    _timeout: Real variable for 'timeout'
199
128
    _interval: Real variable for 'interval'
200
 
    _timeout_milliseconds: Used when calling gobject.timeout_add()
 
129
    _timeout_milliseconds: Used by gobject.timeout_add()
201
130
    _interval_milliseconds: - '' -
202
131
    """
203
132
    def _set_timeout(self, timeout):
223
152
    interval = property(lambda self: self._interval,
224
153
                        _set_interval)
225
154
    del _set_interval
226
 
    def __init__(self, name = None, stop_hook=None, config=None):
227
 
        """Note: the 'checker' key in 'config' sets the
228
 
        'checker_command' attribute and *not* the 'checker'
229
 
        attribute."""
230
 
        if config is None:
231
 
            config = {}
 
155
    def __init__(self, name=None, options=None, stop_hook=None,
 
156
                 fingerprint=None, secret=None, secfile=None,
 
157
                 fqdn=None, timeout=None, interval=-1, checker=None):
 
158
        """Note: the 'checker' argument sets the 'checker_command'
 
159
        attribute and not the 'checker' attribute.."""
232
160
        self.name = name
233
 
        logger.debug(u"Creating client %r", self.name)
234
 
        # Uppercase and remove spaces from fingerprint for later
235
 
        # comparison purposes with return value from the fingerprint()
236
 
        # function
237
 
        self.fingerprint = config["fingerprint"].upper()\
238
 
                           .replace(u" ", u"")
239
 
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
240
 
        if "secret" in config:
241
 
            self.secret = config["secret"].decode(u"base64")
242
 
        elif "secfile" in config:
243
 
            secfile = open(config["secfile"])
244
 
            self.secret = secfile.read()
245
 
            secfile.close()
 
161
        # Uppercase and remove spaces from fingerprint
 
162
        # for later comparison purposes with return value of
 
163
        # the fingerprint() function
 
164
        self.fingerprint = fingerprint.upper().replace(u" ", u"")
 
165
        if secret:
 
166
            self.secret = secret.decode(u"base64")
 
167
        elif secfile:
 
168
            sf = open(secfile)
 
169
            self.secret = sf.read()
 
170
            sf.close()
246
171
        else:
247
 
            raise TypeError(u"No secret or secfile for client %s"
248
 
                            % self.name)
249
 
        self.host = config.get("host", "")
 
172
            raise RuntimeError(u"No secret or secfile for client %s"
 
173
                               % self.name)
 
174
        self.fqdn = fqdn                # string
250
175
        self.created = datetime.datetime.now()
251
 
        self.last_checked_ok = None
252
 
        self.timeout = string_to_delta(config["timeout"])
253
 
        self.interval = string_to_delta(config["interval"])
 
176
        self.last_seen = None
 
177
        if timeout is None:
 
178
            self.timeout = options.timeout
 
179
        else:
 
180
            self.timeout = string_to_delta(timeout)
 
181
        if interval == -1:
 
182
            self.interval = options.interval
 
183
        else:
 
184
            self.interval = string_to_delta(interval)
254
185
        self.stop_hook = stop_hook
255
186
        self.checker = None
256
187
        self.checker_initiator_tag = None
257
188
        self.stop_initiator_tag = None
258
189
        self.checker_callback_tag = None
259
 
        self.check_command = config["checker"]
 
190
        self.check_command = checker
260
191
    def start(self):
261
192
        """Start this client's checker and timeout hooks"""
262
193
        # Schedule a new checker to be started an 'interval' from now,
272
203
                                   self.stop)
273
204
    def stop(self):
274
205
        """Stop this client.
275
 
        The possibility that a client might be restarted is left open,
276
 
        but not currently used."""
 
206
        The possibility that this client might be restarted is left
 
207
        open, but not currently used."""
277
208
        # If this client doesn't have a secret, it is already stopped.
278
 
        if hasattr(self, "secret") and self.secret:
279
 
            logger.info(u"Stopping client %s", self.name)
 
209
        if self.secret:
 
210
            logger.debug(u"Stopping client %s", self.name)
280
211
            self.secret = None
281
212
        else:
282
213
            return False
283
 
        if getattr(self, "stop_initiator_tag", False):
 
214
        if hasattr(self, "stop_initiator_tag") \
 
215
               and self.stop_initiator_tag:
284
216
            gobject.source_remove(self.stop_initiator_tag)
285
217
            self.stop_initiator_tag = None
286
 
        if getattr(self, "checker_initiator_tag", False):
 
218
        if hasattr(self, "checker_initiator_tag") \
 
219
               and self.checker_initiator_tag:
287
220
            gobject.source_remove(self.checker_initiator_tag)
288
221
            self.checker_initiator_tag = None
289
222
        self.stop_checker()
301
234
        self.checker = None
302
235
        if os.WIFEXITED(condition) \
303
236
               and (os.WEXITSTATUS(condition) == 0):
304
 
            logger.info(u"Checker for %(name)s succeeded",
305
 
                        vars(self))
306
 
            self.last_checked_ok = now
 
237
            logger.debug(u"Checker for %(name)s succeeded",
 
238
                         vars(self))
 
239
            self.last_seen = now
307
240
            gobject.source_remove(self.stop_initiator_tag)
308
241
            self.stop_initiator_tag = gobject.timeout_add\
309
242
                                      (self._timeout_milliseconds,
312
245
            logger.warning(u"Checker for %(name)s crashed?",
313
246
                           vars(self))
314
247
        else:
315
 
            logger.info(u"Checker for %(name)s failed",
316
 
                        vars(self))
 
248
            logger.debug(u"Checker for %(name)s failed",
 
249
                         vars(self))
317
250
    def start_checker(self):
318
251
        """Start a new checker subprocess if one is not running.
319
252
        If a checker already exists, leave it running and do
328
261
        # is as it should be.
329
262
        if self.checker is None:
330
263
            try:
331
 
                # In case check_command has exactly one % operator
332
 
                command = self.check_command % self.host
 
264
                command = self.check_command % self.fqdn
333
265
            except TypeError:
334
 
                # Escape attributes for the shell
335
266
                escaped_attrs = dict((key, re.escape(str(val)))
336
267
                                     for key, val in
337
268
                                     vars(self).iteritems())
338
269
                try:
339
270
                    command = self.check_command % escaped_attrs
340
271
                except TypeError, error:
341
 
                    logger.error(u'Could not format string "%s":'
342
 
                                 u' %s', self.check_command, error)
 
272
                    logger.critical(u'Could not format string "%s":'
 
273
                                    u' %s', self.check_command, error)
343
274
                    return True # Try again later
344
275
            try:
345
 
                logger.info(u"Starting checker %r for %s",
346
 
                            command, self.name)
347
 
                # We don't need to redirect stdout and stderr, since
348
 
                # in normal mode, that is already done by daemon(),
349
 
                # and in debug mode we don't want to.  (Stdin is
350
 
                # always replaced by /dev/null.)
351
 
                self.checker = subprocess.Popen(command,
352
 
                                                close_fds=True,
353
 
                                                shell=True, cwd="/")
 
276
                logger.debug(u"Starting checker %r for %s",
 
277
                             command, self.name)
 
278
                self.checker = subprocess.\
 
279
                               Popen(command,
 
280
                                     close_fds=True, shell=True,
 
281
                                     cwd="/")
354
282
                self.checker_callback_tag = gobject.child_watch_add\
355
283
                                            (self.checker.pid,
356
284
                                             self.checker_callback)
357
 
            except OSError, error:
 
285
            except subprocess.OSError, error:
358
286
                logger.error(u"Failed to start subprocess: %s",
359
287
                             error)
360
288
        # Re-run this periodically if run by gobject.timeout_add
364
292
        if self.checker_callback_tag:
365
293
            gobject.source_remove(self.checker_callback_tag)
366
294
            self.checker_callback_tag = None
367
 
        if getattr(self, "checker", None) is None:
 
295
        if not hasattr(self, "checker") or self.checker is None:
368
296
            return
369
 
        logger.debug(u"Stopping checker for %(name)s", vars(self))
 
297
        logger.debug("Stopping checker for %(name)s", vars(self))
370
298
        try:
371
299
            os.kill(self.checker.pid, signal.SIGTERM)
372
300
            #os.sleep(0.5)
373
301
            #if self.checker.poll() is None:
374
302
            #    os.kill(self.checker.pid, signal.SIGKILL)
375
303
        except OSError, error:
376
 
            if error.errno != errno.ESRCH: # No such process
 
304
            if error.errno != errno.ESRCH:
377
305
                raise
378
306
        self.checker = None
379
 
    def still_valid(self):
 
307
    def still_valid(self, now=None):
380
308
        """Has the timeout not yet passed for this client?"""
381
 
        now = datetime.datetime.now()
382
 
        if self.last_checked_ok is None:
 
309
        if now is None:
 
310
            now = datetime.datetime.now()
 
311
        if self.last_seen is None:
383
312
            return now < (self.created + self.timeout)
384
313
        else:
385
 
            return now < (self.last_checked_ok + self.timeout)
 
314
            return now < (self.last_seen + self.timeout)
386
315
 
387
316
 
388
317
def peer_certificate(session):
404
333
 
405
334
def fingerprint(openpgp):
406
335
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
 
336
    # New empty GnuTLS certificate
 
337
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
 
338
    gnutls.library.functions.gnutls_openpgp_crt_init\
 
339
        (ctypes.byref(crt))
407
340
    # New GnuTLS "datum" with the OpenPGP public key
408
341
    datum = gnutls.library.types.gnutls_datum_t\
409
342
        (ctypes.cast(ctypes.c_char_p(openpgp),
410
343
                     ctypes.POINTER(ctypes.c_ubyte)),
411
344
         ctypes.c_uint(len(openpgp)))
412
 
    # New empty GnuTLS certificate
413
 
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
414
 
    gnutls.library.functions.gnutls_openpgp_crt_init\
415
 
        (ctypes.byref(crt))
416
345
    # Import the OpenPGP public key into the certificate
417
 
    gnutls.library.functions.gnutls_openpgp_crt_import\
418
 
                    (crt, ctypes.byref(datum),
419
 
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
420
 
    # Verify the self signature in the key
421
 
    crtverify = ctypes.c_uint()
422
 
    gnutls.library.functions.gnutls_openpgp_crt_verify_self\
423
 
        (crt, 0, ctypes.byref(crtverify))
424
 
    if crtverify.value != 0:
425
 
        gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
426
 
        raise gnutls.errors.CertificateSecurityError("Verify failed")
 
346
    ret = gnutls.library.functions.gnutls_openpgp_crt_import\
 
347
        (crt,
 
348
         ctypes.byref(datum),
 
349
         gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
427
350
    # New buffer for the fingerprint
428
 
    buf = ctypes.create_string_buffer(20)
429
 
    buf_len = ctypes.c_size_t()
 
351
    buffer = ctypes.create_string_buffer(20)
 
352
    buffer_length = ctypes.c_size_t()
430
353
    # Get the fingerprint from the certificate into the buffer
431
354
    gnutls.library.functions.gnutls_openpgp_crt_get_fingerprint\
432
 
        (crt, ctypes.byref(buf), ctypes.byref(buf_len))
 
355
        (crt, ctypes.byref(buffer), ctypes.byref(buffer_length))
433
356
    # Deinit the certificate
434
357
    gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
435
358
    # Convert the buffer to a Python bytestring
436
 
    fpr = ctypes.string_at(buf, buf_len.value)
 
359
    fpr = ctypes.string_at(buffer, buffer_length.value)
437
360
    # Convert the bytestring to hexadecimal notation
438
361
    hex_fpr = u''.join(u"%02X" % ord(char) for char in fpr)
439
362
    return hex_fpr
440
363
 
441
364
 
442
 
class TCP_handler(SocketServer.BaseRequestHandler, object):
 
365
class tcp_handler(SocketServer.BaseRequestHandler, object):
443
366
    """A TCP request handler class.
444
367
    Instantiated by IPv6_TCPServer for each request to handle it.
445
368
    Note: This will run in its own forked process."""
446
369
    
447
370
    def handle(self):
448
 
        logger.info(u"TCP connection from: %s",
 
371
        logger.debug(u"TCP connection from: %s",
449
372
                     unicode(self.client_address))
450
 
        session = gnutls.connection.ClientSession\
451
 
                  (self.request, gnutls.connection.X509Credentials())
452
 
        
453
 
        line = self.request.makefile().readline()
454
 
        logger.debug(u"Protocol version: %r", line)
455
 
        try:
456
 
            if int(line.strip().split()[0]) > 1:
457
 
                raise RuntimeError
458
 
        except (ValueError, IndexError, RuntimeError), error:
459
 
            logger.error(u"Unknown protocol version: %s", error)
460
 
            return
461
 
        
462
 
        # Note: gnutls.connection.X509Credentials is really a generic
463
 
        # GnuTLS certificate credentials object so long as no X.509
464
 
        # keys are added to it.  Therefore, we can use it here despite
465
 
        # using OpenPGP certificates.
 
373
        session = gnutls.connection.ClientSession(self.request,
 
374
                                                  gnutls.connection.\
 
375
                                                  X509Credentials())
466
376
        
467
377
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
468
378
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
469
379
        #                "+DHE-DSS"))
470
 
        priority = "NORMAL"             # Fallback default, since this
471
 
                                        # MUST be set.
472
 
        if self.server.settings["priority"]:
473
 
            priority = self.server.settings["priority"]
 
380
        priority = "SECURE256"
 
381
        
474
382
        gnutls.library.functions.gnutls_priority_set_direct\
475
 
            (session._c_object, priority, None)
 
383
            (session._c_object, priority, None);
476
384
        
477
385
        try:
478
386
            session.handshake()
479
387
        except gnutls.errors.GNUTLSError, error:
480
 
            logger.warning(u"Handshake failed: %s", error)
 
388
            logger.debug(u"Handshake failed: %s", error)
481
389
            # Do not run session.bye() here: the session is not
482
390
            # established.  Just abandon the request.
483
391
            return
484
392
        try:
485
393
            fpr = fingerprint(peer_certificate(session))
486
394
        except (TypeError, gnutls.errors.GNUTLSError), error:
487
 
            logger.warning(u"Bad certificate: %s", error)
 
395
            logger.debug(u"Bad certificate: %s", error)
488
396
            session.bye()
489
397
            return
490
398
        logger.debug(u"Fingerprint: %s", fpr)
493
401
            if c.fingerprint == fpr:
494
402
                client = c
495
403
                break
496
 
        if not client:
497
 
            logger.warning(u"Client not found for fingerprint: %s",
498
 
                           fpr)
499
 
            session.bye()
500
 
            return
501
404
        # Have to check if client.still_valid(), since it is possible
502
405
        # that the client timed out while establishing the GnuTLS
503
406
        # session.
504
 
        if not client.still_valid():
505
 
            logger.warning(u"Client %(name)s is invalid",
506
 
                           vars(client))
 
407
        if (not client) or (not client.still_valid()):
 
408
            if client:
 
409
                logger.debug(u"Client %(name)s is invalid",
 
410
                             vars(client))
 
411
            else:
 
412
                logger.debug(u"Client not found for fingerprint: %s",
 
413
                             fpr)
507
414
            session.bye()
508
415
            return
509
416
        sent_size = 0
519
426
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
520
427
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
521
428
    Attributes:
522
 
        settings:       Server settings
 
429
        options:        Command line options
523
430
        clients:        Set() of Client objects
524
 
        enabled:        Boolean; whether this server is activated yet
525
431
    """
526
432
    address_family = socket.AF_INET6
527
433
    def __init__(self, *args, **kwargs):
528
 
        if "settings" in kwargs:
529
 
            self.settings = kwargs["settings"]
530
 
            del kwargs["settings"]
 
434
        if "options" in kwargs:
 
435
            self.options = kwargs["options"]
 
436
            del kwargs["options"]
531
437
        if "clients" in kwargs:
532
438
            self.clients = kwargs["clients"]
533
439
            del kwargs["clients"]
534
 
        self.enabled = False
535
 
        super(IPv6_TCPServer, self).__init__(*args, **kwargs)
 
440
        return super(type(self), self).__init__(*args, **kwargs)
536
441
    def server_bind(self):
537
442
        """This overrides the normal server_bind() function
538
443
        to bind to an interface if one was specified, and also NOT to
539
444
        bind to an address or port if they were not specified."""
540
 
        if self.settings["interface"]:
541
 
            # 25 is from /usr/include/asm-i486/socket.h
542
 
            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
543
449
            try:
544
450
                self.socket.setsockopt(socket.SOL_SOCKET,
545
 
                                       SO_BINDTODEVICE,
546
 
                                       self.settings["interface"])
 
451
                                       socket.SO_BINDTODEVICE,
 
452
                                       self.options.interface)
547
453
            except socket.error, error:
548
454
                if error[0] == errno.EPERM:
549
 
                    logger.error(u"No permission to"
550
 
                                 u" bind to interface %s",
551
 
                                 self.settings["interface"])
 
455
                    logger.warning(u"No permission to"
 
456
                                   u" bind to interface %s",
 
457
                                   self.options.interface)
552
458
                else:
553
459
                    raise error
554
460
        # Only bind(2) the socket if we really need to.
557
463
                in6addr_any = "::"
558
464
                self.server_address = (in6addr_any,
559
465
                                       self.server_address[1])
560
 
            elif not self.server_address[1]:
 
466
            elif self.server_address[1] is None:
561
467
                self.server_address = (self.server_address[0],
562
468
                                       0)
563
 
#                 if self.settings["interface"]:
564
 
#                     self.server_address = (self.server_address[0],
565
 
#                                            0, # port
566
 
#                                            0, # flowinfo
567
 
#                                            if_nametoindex
568
 
#                                            (self.settings
569
 
#                                             ["interface"]))
570
 
            return super(IPv6_TCPServer, self).server_bind()
571
 
    def server_activate(self):
572
 
        if self.enabled:
573
 
            return super(IPv6_TCPServer, self).server_activate()
574
 
    def enable(self):
575
 
        self.enabled = True
 
469
            return super(type(self), self).server_bind()
576
470
 
577
471
 
578
472
def string_to_delta(interval):
588
482
    datetime.timedelta(1)
589
483
    >>> string_to_delta(u'1w')
590
484
    datetime.timedelta(7)
591
 
    >>> string_to_delta('5m 30s')
592
 
    datetime.timedelta(0, 330)
593
485
    """
594
 
    timevalue = datetime.timedelta(0)
595
 
    for s in interval.split():
596
 
        try:
597
 
            suffix = unicode(s[-1])
598
 
            value = int(s[:-1])
599
 
            if suffix == u"d":
600
 
                delta = datetime.timedelta(value)
601
 
            elif suffix == u"s":
602
 
                delta = datetime.timedelta(0, value)
603
 
            elif suffix == u"m":
604
 
                delta = datetime.timedelta(0, 0, 0, 0, value)
605
 
            elif suffix == u"h":
606
 
                delta = datetime.timedelta(0, 0, 0, 0, 0, value)
607
 
            elif suffix == u"w":
608
 
                delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
609
 
            else:
610
 
                raise ValueError
611
 
        except (ValueError, IndexError):
 
486
    try:
 
487
        suffix=unicode(interval[-1])
 
488
        value=int(interval[:-1])
 
489
        if suffix == u"d":
 
490
            delta = datetime.timedelta(value)
 
491
        elif suffix == u"s":
 
492
            delta = datetime.timedelta(0, value)
 
493
        elif suffix == u"m":
 
494
            delta = datetime.timedelta(0, 0, 0, 0, value)
 
495
        elif suffix == u"h":
 
496
            delta = datetime.timedelta(0, 0, 0, 0, 0, value)
 
497
        elif suffix == u"w":
 
498
            delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
 
499
        else:
612
500
            raise ValueError
613
 
        timevalue += delta
614
 
    return timevalue
 
501
    except (ValueError, IndexError):
 
502
        raise ValueError
 
503
    return delta
 
504
 
 
505
 
 
506
def add_service():
 
507
    """Derived from the Avahi example code"""
 
508
    global group, serviceName, serviceType, servicePort, serviceTXT, \
 
509
           domain, host
 
510
    if group is None:
 
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)
 
519
    
 
520
    group.AddService(
 
521
            serviceInterface,           # interface
 
522
            avahi.PROTO_INET6,          # protocol
 
523
            dbus.UInt32(0),             # flags
 
524
            serviceName, serviceType,
 
525
            domain, host,
 
526
            dbus.UInt16(servicePort),
 
527
            avahi.string_array_to_txt_array(serviceTXT))
 
528
    group.Commit()
 
529
 
 
530
 
 
531
def remove_service():
 
532
    """From the Avahi example code"""
 
533
    global group
 
534
    
 
535
    if not group is None:
 
536
        group.Reset()
615
537
 
616
538
 
617
539
def server_state_changed(state):
618
540
    """Derived from the Avahi example code"""
619
541
    if state == avahi.SERVER_COLLISION:
620
 
        logger.error(u"Zeroconf server name collision")
621
 
        service.remove()
 
542
        logger.warning(u"Server name collision")
 
543
        remove_service()
622
544
    elif state == avahi.SERVER_RUNNING:
623
 
        service.add()
 
545
        add_service()
624
546
 
625
547
 
626
548
def entry_group_state_changed(state, error):
627
549
    """Derived from the Avahi example code"""
628
 
    logger.debug(u"Avahi state change: %i", state)
 
550
    global serviceName, server, rename_count
 
551
    
 
552
    logger.debug(u"state change: %i", state)
629
553
    
630
554
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
631
 
        logger.debug(u"Zeroconf service established.")
 
555
        logger.debug(u"Service established.")
632
556
    elif state == avahi.ENTRY_GROUP_COLLISION:
633
 
        logger.warning(u"Zeroconf service name collision.")
634
 
        service.rename()
 
557
        
 
558
        rename_count = rename_count - 1
 
559
        if rename_count > 0:
 
560
            name = server.GetAlternativeServiceName(name)
 
561
            logger.warning(u"Service name collision, "
 
562
                           u"changing name to '%s' ...", name)
 
563
            remove_service()
 
564
            add_service()
 
565
            
 
566
        else:
 
567
            logger.error(u"No suitable service name found after %i"
 
568
                         u" retries, exiting.", n_rename)
 
569
            killme(1)
635
570
    elif state == avahi.ENTRY_GROUP_FAILURE:
636
 
        logger.critical(u"Avahi: Error in group state changed %s",
637
 
                        unicode(error))
638
 
        raise AvahiGroupError("State changed: %s", str(error))
 
571
        logger.error(u"Error in group state changed %s",
 
572
                     unicode(error))
 
573
        killme(1)
 
574
 
639
575
 
640
576
def if_nametoindex(interface):
641
 
    """Call the C function if_nametoindex(), or equivalent"""
642
 
    global if_nametoindex
 
577
    """Call the C function if_nametoindex()"""
643
578
    try:
644
 
        if_nametoindex = ctypes.cdll.LoadLibrary\
645
 
            (ctypes.util.find_library("c")).if_nametoindex
 
579
        libc = ctypes.cdll.LoadLibrary("libc.so.6")
 
580
        return libc.if_nametoindex(interface)
646
581
    except (OSError, AttributeError):
647
582
        if "struct" not in sys.modules:
648
583
            import struct
649
584
        if "fcntl" not in sys.modules:
650
585
            import fcntl
651
 
        def if_nametoindex(interface):
652
 
            "Get an interface index the hard way, i.e. using fcntl()"
653
 
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
654
 
            s = socket.socket()
655
 
            ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
656
 
                                struct.pack("16s16x", interface))
657
 
            s.close()
658
 
            interface_index = struct.unpack("I", ifreq[16:20])[0]
659
 
            return interface_index
660
 
    return if_nametoindex(interface)
661
 
 
662
 
 
663
 
def daemon(nochdir = False, noclose = False):
 
586
        SIOCGIFINDEX = 0x8933      # From /usr/include/linux/sockios.h
 
587
        s = socket.socket()
 
588
        ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
 
589
                            struct.pack("16s16x", interface))
 
590
        s.close()
 
591
        interface_index = struct.unpack("I", ifreq[16:20])[0]
 
592
        return interface_index
 
593
 
 
594
 
 
595
def daemon(nochdir, noclose):
664
596
    """See daemon(3).  Standard BSD Unix function.
665
597
    This should really exist as os.daemon, but it doesn't (yet)."""
666
598
    if os.fork():
668
600
    os.setsid()
669
601
    if not nochdir:
670
602
        os.chdir("/")
671
 
    if os.fork():
672
 
        sys.exit()
673
603
    if not noclose:
674
604
        # Close all standard open file descriptors
675
 
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
 
605
        null = os.open("/dev/null", os.O_NOCTTY | os.O_RDWR)
676
606
        if not stat.S_ISCHR(os.fstat(null).st_mode):
677
607
            raise OSError(errno.ENODEV,
678
608
                          "/dev/null not a character device")
683
613
            os.close(null)
684
614
 
685
615
 
 
616
def killme(status = 0):
 
617
    logger.debug("Stopping server with exit status %d", status)
 
618
    exitstatus = status
 
619
    if main_loop_started:
 
620
        main_loop.quit()
 
621
    else:
 
622
        sys.exit(status)
 
623
 
 
624
 
686
625
def main():
687
 
    parser = OptionParser(version = "%%prog %s" % version)
 
626
    global exitstatus
 
627
    exitstatus = 0
 
628
    global main_loop_started
 
629
    main_loop_started = False
 
630
    
 
631
    parser = OptionParser()
688
632
    parser.add_option("-i", "--interface", type="string",
689
 
                      metavar="IF", help="Bind to interface IF")
690
 
    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,
691
636
                      help="Address to listen for requests on")
692
 
    parser.add_option("-p", "--port", type="int",
 
637
    parser.add_option("-p", "--port", type="int", default=None,
693
638
                      help="Port number to receive requests on")
 
639
    parser.add_option("--timeout", type="string", # Parsed later
 
640
                      default="1h",
 
641
                      help="Amount of downtime allowed for clients")
 
642
    parser.add_option("--interval", type="string", # Parsed later
 
643
                      default="5m",
 
644
                      help="How often to check that a client is up")
694
645
    parser.add_option("--check", action="store_true", default=False,
695
646
                      help="Run self-test")
696
 
    parser.add_option("--debug", action="store_true",
697
 
                      help="Debug mode; run in foreground and log to"
698
 
                      " terminal")
699
 
    parser.add_option("--priority", type="string", help="GnuTLS"
700
 
                      " priority string (see GnuTLS documentation)")
701
 
    parser.add_option("--servicename", type="string", metavar="NAME",
702
 
                      help="Zeroconf service name")
703
 
    parser.add_option("--configdir", type="string",
704
 
                      default="/etc/mandos", metavar="DIR",
705
 
                      help="Directory to search for configuration"
706
 
                      " files")
707
 
    options = parser.parse_args()[0]
 
647
    parser.add_option("--debug", action="store_true", default=False,
 
648
                      help="Debug mode")
 
649
    (options, args) = parser.parse_args()
708
650
    
709
651
    if options.check:
710
652
        import doctest
711
653
        doctest.testmod()
712
654
        sys.exit()
713
655
    
714
 
    # Default values for config file for server-global settings
715
 
    server_defaults = { "interface": "",
716
 
                        "address": "",
717
 
                        "port": "",
718
 
                        "debug": "False",
719
 
                        "priority":
720
 
                        "SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
721
 
                        "servicename": "Mandos",
722
 
                        }
723
 
    
724
 
    # Parse config file for server-global settings
725
 
    server_config = ConfigParser.SafeConfigParser(server_defaults)
726
 
    del server_defaults
727
 
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
728
 
    # Convert the SafeConfigParser object to a dict
729
 
    server_settings = server_config.defaults()
730
 
    # Use getboolean on the boolean config option
731
 
    server_settings["debug"] = server_config.getboolean\
732
 
                               ("DEFAULT", "debug")
733
 
    del server_config
734
 
    
735
 
    # Override the settings from the config file with command line
736
 
    # options, if set.
737
 
    for option in ("interface", "address", "port", "debug",
738
 
                   "priority", "servicename", "configdir"):
739
 
        value = getattr(options, option)
740
 
        if value is not None:
741
 
            server_settings[option] = value
742
 
    del options
743
 
    # Now we have our good server settings in "server_settings"
744
 
    
745
 
    debug = server_settings["debug"]
746
 
    
747
 
    if not debug:
748
 
        syslogger.setLevel(logging.WARNING)
749
 
        console.setLevel(logging.WARNING)
750
 
    
751
 
    if server_settings["servicename"] != "Mandos":
752
 
        syslogger.setFormatter(logging.Formatter\
753
 
                               ('Mandos (%s): %%(levelname)s:'
754
 
                                ' %%(message)s'
755
 
                                % server_settings["servicename"]))
756
 
    
757
 
    # Parse config file with clients
758
 
    client_defaults = { "timeout": "1h",
759
 
                        "interval": "5m",
760
 
                        "checker": "fping -q -- %(host)s",
761
 
                        "host": "",
762
 
                        }
763
 
    client_config = ConfigParser.SafeConfigParser(client_defaults)
764
 
    client_config.read(os.path.join(server_settings["configdir"],
765
 
                                    "clients.conf"))
766
 
    
767
 
    clients = Set()
768
 
    tcp_server = IPv6_TCPServer((server_settings["address"],
769
 
                                 server_settings["port"]),
770
 
                                TCP_handler,
771
 
                                settings=server_settings,
772
 
                                clients=clients)
773
 
    pidfilename = "/var/run/mandos.pid"
774
 
    try:
775
 
        pidfile = open(pidfilename, "w")
776
 
    except IOError, error:
777
 
        logger.error("Could not open file %r", pidfilename)
778
 
    
779
 
    uid = 65534
780
 
    gid = 65534
781
 
    try:
782
 
        uid = pwd.getpwnam("mandos").pw_uid
783
 
    except KeyError:
784
 
        try:
785
 
            uid = pwd.getpwnam("nobody").pw_uid
786
 
        except KeyError:
787
 
            pass
788
 
    try:
789
 
        gid = pwd.getpwnam("mandos").pw_gid
790
 
    except KeyError:
791
 
        try:
792
 
            gid = pwd.getpwnam("nogroup").pw_gid
793
 
        except KeyError:
794
 
            pass
795
 
    try:
796
 
        os.setuid(uid)
797
 
        os.setgid(gid)
798
 
    except OSError, error:
799
 
        if error[0] != errno.EPERM:
800
 
            raise error
801
 
    
802
 
    global service
803
 
    service = AvahiService(name = server_settings["servicename"],
804
 
                           servicetype = "_mandos._tcp", )
805
 
    if server_settings["interface"]:
806
 
        service.interface = if_nametoindex\
807
 
                            (server_settings["interface"])
 
656
    # Parse the time arguments
 
657
    try:
 
658
        options.timeout = string_to_delta(options.timeout)
 
659
    except ValueError:
 
660
        parser.error("option --timeout: Unparseable time")
 
661
    try:
 
662
        options.interval = string_to_delta(options.interval)
 
663
    except ValueError:
 
664
        parser.error("option --interval: Unparseable time")
 
665
    
 
666
    # Parse config file
 
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")
808
671
    
809
672
    global main_loop
810
673
    global bus
813
676
    DBusGMainLoop(set_as_default=True )
814
677
    main_loop = gobject.MainLoop()
815
678
    bus = dbus.SystemBus()
816
 
    server = dbus.Interface(bus.get_object(avahi.DBUS_NAME,
817
 
                                           avahi.DBUS_PATH_SERVER),
818
 
                            avahi.DBUS_INTERFACE_SERVER)
 
679
    server = dbus.Interface(
 
680
            bus.get_object( avahi.DBUS_NAME, avahi.DBUS_PATH_SERVER ),
 
681
            avahi.DBUS_INTERFACE_SERVER )
819
682
    # End of Avahi example code
820
683
    
 
684
    debug = options.debug
 
685
    
 
686
    if debug:
 
687
        console = logging.StreamHandler()
 
688
        # console.setLevel(logging.DEBUG)
 
689
        console.setFormatter(logging.Formatter\
 
690
                             ('%(levelname)s: %(message)s'))
 
691
        logger.addHandler(console)
 
692
        del console
 
693
    
 
694
    clients = Set()
821
695
    def remove_from_clients(client):
822
696
        clients.remove(client)
823
697
        if not clients:
824
 
            logger.critical(u"No clients left, exiting")
825
 
            sys.exit()
 
698
            logger.debug(u"No clients left, exiting")
 
699
            killme()
826
700
    
827
 
    clients.update(Set(Client(name = section,
 
701
    clients.update(Set(Client(name=section, options=options,
828
702
                              stop_hook = remove_from_clients,
829
 
                              config
830
 
                              = dict(client_config.items(section)))
 
703
                              **(dict(client_config\
 
704
                                      .items(section))))
831
705
                       for section in client_config.sections()))
832
 
    if not clients:
833
 
        logger.critical(u"No clients defined")
834
 
        sys.exit(1)
835
 
    
836
 
    if debug:
837
 
        # Redirect stdin so all checkers get /dev/null
838
 
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
839
 
        os.dup2(null, sys.stdin.fileno())
840
 
        if null > 2:
841
 
            os.close(null)
842
 
    else:
843
 
        # No console logging
844
 
        logger.removeHandler(console)
845
 
        # Close all input and output, do double fork, etc.
846
 
        daemon()
847
 
    
848
 
    try:
849
 
        pid = os.getpid()
850
 
        pidfile.write(str(pid) + "\n")
851
 
        pidfile.close()
852
 
        del pidfile
853
 
    except IOError:
854
 
        logger.error(u"Could not write to file %r with PID %d",
855
 
                     pidfilename, pid)
856
 
    except NameError:
857
 
        # "pidfile" was never created
858
 
        pass
859
 
    del pidfilename
 
706
    
 
707
    if not debug:
 
708
        daemon(False, False)
860
709
    
861
710
    def cleanup():
862
711
        "Cleanup function; run on exit"
876
725
    
877
726
    if not debug:
878
727
        signal.signal(signal.SIGINT, signal.SIG_IGN)
879
 
    signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
880
 
    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())
881
730
    
882
731
    for client in clients:
883
732
        client.start()
884
733
    
885
 
    tcp_server.enable()
886
 
    tcp_server.server_activate()
887
 
    
888
 
    # Find out what port we got
889
 
    service.port = tcp_server.socket.getsockname()[1]
890
 
    logger.info(u"Now listening on address %r, port %d, flowinfo %d,"
891
 
                u" scope_id %d" % tcp_server.socket.getsockname())
892
 
    
893
 
    #service.interface = tcp_server.socket.getsockname()[3]
894
 
    
895
 
    try:
896
 
        # From the Avahi example code
897
 
        server.connect_to_signal("StateChanged", server_state_changed)
898
 
        try:
899
 
            server_state_changed(server.GetState())
900
 
        except dbus.exceptions.DBusException, error:
901
 
            logger.critical(u"DBusException: %s", error)
902
 
            sys.exit(1)
903
 
        # End of Avahi example code
904
 
        
905
 
        gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
906
 
                             lambda *args, **kwargs:
907
 
                             tcp_server.handle_request\
908
 
                             (*args[2:], **kwargs) or True)
909
 
        
910
 
        logger.debug(u"Starting main loop")
 
734
    tcp_server = IPv6_TCPServer((options.address, options.port),
 
735
                                tcp_handler,
 
736
                                options=options,
 
737
                                clients=clients)
 
738
    # Find out what random port we got
 
739
    global servicePort
 
740
    servicePort = tcp_server.socket.getsockname()[1]
 
741
    logger.debug(u"Now listening on port %d", servicePort)
 
742
    
 
743
    if options.interface is not None:
 
744
        global serviceInterface
 
745
        serviceInterface = if_nametoindex(options.interface)
 
746
    
 
747
    # From the Avahi example code
 
748
    server.connect_to_signal("StateChanged", server_state_changed)
 
749
    try:
 
750
        server_state_changed(server.GetState())
 
751
    except dbus.exceptions.DBusException, error:
 
752
        logger.critical(u"DBusException: %s", error)
 
753
        killme(1)
 
754
    # End of Avahi example code
 
755
    
 
756
    gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
 
757
                         lambda *args, **kwargs:
 
758
                         tcp_server.handle_request(*args[2:],
 
759
                                                   **kwargs) or True)
 
760
    try:
 
761
        logger.debug("Starting main loop")
 
762
        main_loop_started = True
911
763
        main_loop.run()
912
 
    except AvahiError, error:
913
 
        logger.critical(u"AvahiError: %s" + unicode(error))
914
 
        sys.exit(1)
915
764
    except KeyboardInterrupt:
916
765
        if debug:
917
766
            print
 
767
    
 
768
    sys.exit(exitstatus)
918
769
 
919
770
if __name__ == '__main__':
920
771
    main()