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  • Committer: Teddy Hogeborn
  • Date: 2008-10-18 11:17:22 UTC
  • Revision ID: teddy@fukt.bsnet.se-20081018111722-jtbz35c031lxuuc9
* debian/mandos-client.docs (NEWS): Added.
* debian/mandos.docs (NEWS): - '' -

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mandos
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# This program is partly derived from an example program for an Avahi
7
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# service publisher, downloaded from
8
8
# <http://avahi.org/wiki/PythonPublishExample>.  This includes the
9
 
# following functions: "add_service", "remove_service",
10
 
# "server_state_changed", "entry_group_state_changed", and some lines
11
 
# in "main".
 
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".
12
12
# 
13
 
# Everything else is Copyright © 2007-2008 Teddy Hogeborn and Björn
14
 
# Påhlsson.
 
13
# Everything else is
 
14
# Copyright © 2008 Teddy Hogeborn & Björn Påhlsson
15
15
# 
16
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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
25
# 
26
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# You should have received a copy of the GNU General Public License
27
 
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
27
# along with this program.  If not, see
 
28
# <http://www.gnu.org/licenses/>.
28
29
# 
29
 
# Contact the authors at <https://www.fukt.bsnet.se/~belorn/> and
30
 
# <https://www.fukt.bsnet.se/~teddy/>.
 
30
# Contact the authors at <mandos@fukt.bsnet.se>.
31
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# 
32
32
 
33
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from __future__ import division
34
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35
35
import SocketServer
36
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import socket
37
 
import select
38
37
from optparse import OptionParser
39
38
import datetime
40
39
import errno
55
54
import stat
56
55
import logging
57
56
import logging.handlers
 
57
import pwd
58
58
 
59
59
import dbus
60
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import gobject
61
61
import avahi
62
62
from dbus.mainloop.glib import DBusGMainLoop
63
63
import ctypes
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
 
 
 
64
import ctypes.util
 
65
 
 
66
version = "1.0.2"
76
67
 
77
68
logger = logging.Logger('mandos')
78
69
syslogger = logging.handlers.SysLogHandler\
79
 
            (facility = logging.handlers.SysLogHandler.LOG_DAEMON)
 
70
            (facility = logging.handlers.SysLogHandler.LOG_DAEMON,
 
71
             address = "/dev/log")
80
72
syslogger.setFormatter(logging.Formatter\
81
 
                        ('%(levelname)s: %(message)s'))
 
73
                        ('Mandos: %(levelname)s: %(message)s'))
82
74
logger.addHandler(syslogger)
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
 
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
 
89
168
# From the Avahi example code:
90
 
serviceName = None
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
 
169
group = None                            # our entry group
99
170
# End of Avahi example code
100
171
 
101
172
 
106
177
    fingerprint: string (40 or 32 hexadecimal digits); used to
107
178
                 uniquely identify the client
108
179
    secret:    bytestring; sent verbatim (over TLS) to client
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
 
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
114
185
    interval:  datetime.timedelta(); How often to start a new checker
115
186
    stop_hook: If set, called by stop() as stop_hook(self)
116
187
    checker:   subprocess.Popen(); a running checker process used
117
188
                                   to see if the client lives.
118
 
                                   Is None if no process is running.
 
189
                                   'None' if no process is running.
119
190
    checker_initiator_tag: a gobject event source tag, or None
120
191
    stop_initiator_tag:    - '' -
121
192
    checker_callback_tag:  - '' -
122
193
    checker_command: string; External command which is run to check if
123
 
                     client lives.  %()s expansions are done at
 
194
                     client lives.  %() expansions are done at
124
195
                     runtime with vars(self) as dict, so that for
125
196
                     instance %(name)s can be used in the command.
126
197
    Private attibutes:
127
198
    _timeout: Real variable for 'timeout'
128
199
    _interval: Real variable for 'interval'
129
 
    _timeout_milliseconds: Used by gobject.timeout_add()
 
200
    _timeout_milliseconds: Used when calling gobject.timeout_add()
130
201
    _interval_milliseconds: - '' -
131
202
    """
132
203
    def _set_timeout(self, timeout):
152
223
    interval = property(lambda self: self._interval,
153
224
                        _set_interval)
154
225
    del _set_interval
155
 
    def __init__(self, name=None, stop_hook=None, fingerprint=None,
156
 
                 secret=None, secfile=None, fqdn=None, timeout=None,
157
 
                 interval=-1, checker=None):
158
 
        """Note: the 'checker' argument sets the 'checker_command'
159
 
        attribute and not the 'checker' attribute.."""
 
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 = {}
160
232
        self.name = name
161
233
        logger.debug(u"Creating client %r", self.name)
162
 
        # Uppercase and remove spaces from fingerprint
163
 
        # for later comparison purposes with return value of
164
 
        # the fingerprint() function
165
 
        self.fingerprint = fingerprint.upper().replace(u" ", u"")
 
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"")
166
239
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
167
 
        if secret:
168
 
            self.secret = secret.decode(u"base64")
169
 
        elif secfile:
170
 
            sf = open(secfile)
171
 
            self.secret = sf.read()
172
 
            sf.close()
 
240
        if "secret" in config:
 
241
            self.secret = config["secret"].decode(u"base64")
 
242
        elif "secfile" in config:
 
243
            secfile = open(os.path.expanduser(os.path.expandvars
 
244
                                              (config["secfile"])))
 
245
            self.secret = secfile.read()
 
246
            secfile.close()
173
247
        else:
174
 
            raise RuntimeError(u"No secret or secfile for client %s"
175
 
                               % self.name)
176
 
        self.fqdn = fqdn                # string
 
248
            raise TypeError(u"No secret or secfile for client %s"
 
249
                            % self.name)
 
250
        self.host = config.get("host", "")
177
251
        self.created = datetime.datetime.now()
178
 
        self.last_seen = None
179
 
        self.timeout = string_to_delta(timeout)
180
 
        self.interval = string_to_delta(interval)
 
252
        self.last_checked_ok = None
 
253
        self.timeout = string_to_delta(config["timeout"])
 
254
        self.interval = string_to_delta(config["interval"])
181
255
        self.stop_hook = stop_hook
182
256
        self.checker = None
183
257
        self.checker_initiator_tag = None
184
258
        self.stop_initiator_tag = None
185
259
        self.checker_callback_tag = None
186
 
        self.check_command = checker
 
260
        self.check_command = config["checker"]
187
261
    def start(self):
188
262
        """Start this client's checker and timeout hooks"""
189
263
        # Schedule a new checker to be started an 'interval' from now,
199
273
                                   self.stop)
200
274
    def stop(self):
201
275
        """Stop this client.
202
 
        The possibility that this client might be restarted is left
203
 
        open, but not currently used."""
 
276
        The possibility that a client might be restarted is left open,
 
277
        but not currently used."""
204
278
        # If this client doesn't have a secret, it is already stopped.
205
 
        if self.secret:
206
 
            logger.debug(u"Stopping client %s", self.name)
 
279
        if hasattr(self, "secret") and self.secret:
 
280
            logger.info(u"Stopping client %s", self.name)
207
281
            self.secret = None
208
282
        else:
209
283
            return False
210
 
        if hasattr(self, "stop_initiator_tag") \
211
 
               and self.stop_initiator_tag:
 
284
        if getattr(self, "stop_initiator_tag", False):
212
285
            gobject.source_remove(self.stop_initiator_tag)
213
286
            self.stop_initiator_tag = None
214
 
        if hasattr(self, "checker_initiator_tag") \
215
 
               and self.checker_initiator_tag:
 
287
        if getattr(self, "checker_initiator_tag", False):
216
288
            gobject.source_remove(self.checker_initiator_tag)
217
289
            self.checker_initiator_tag = None
218
290
        self.stop_checker()
230
302
        self.checker = None
231
303
        if os.WIFEXITED(condition) \
232
304
               and (os.WEXITSTATUS(condition) == 0):
233
 
            logger.debug(u"Checker for %(name)s succeeded",
234
 
                         vars(self))
235
 
            self.last_seen = now
 
305
            logger.info(u"Checker for %(name)s succeeded",
 
306
                        vars(self))
 
307
            self.last_checked_ok = now
236
308
            gobject.source_remove(self.stop_initiator_tag)
237
309
            self.stop_initiator_tag = gobject.timeout_add\
238
310
                                      (self._timeout_milliseconds,
241
313
            logger.warning(u"Checker for %(name)s crashed?",
242
314
                           vars(self))
243
315
        else:
244
 
            logger.debug(u"Checker for %(name)s failed",
245
 
                         vars(self))
 
316
            logger.info(u"Checker for %(name)s failed",
 
317
                        vars(self))
246
318
    def start_checker(self):
247
319
        """Start a new checker subprocess if one is not running.
248
320
        If a checker already exists, leave it running and do
257
329
        # is as it should be.
258
330
        if self.checker is None:
259
331
            try:
260
 
                command = self.check_command % self.fqdn
 
332
                # In case check_command has exactly one % operator
 
333
                command = self.check_command % self.host
261
334
            except TypeError:
 
335
                # Escape attributes for the shell
262
336
                escaped_attrs = dict((key, re.escape(str(val)))
263
337
                                     for key, val in
264
338
                                     vars(self).iteritems())
265
339
                try:
266
340
                    command = self.check_command % escaped_attrs
267
341
                except TypeError, error:
268
 
                    logger.critical(u'Could not format string "%s":'
269
 
                                    u' %s', self.check_command, error)
 
342
                    logger.error(u'Could not format string "%s":'
 
343
                                 u' %s', self.check_command, error)
270
344
                    return True # Try again later
271
345
            try:
272
 
                logger.debug(u"Starting checker %r for %s",
273
 
                             command, self.name)
274
 
                self.checker = subprocess.\
275
 
                               Popen(command,
276
 
                                     close_fds=True, shell=True,
277
 
                                     cwd="/")
 
346
                logger.info(u"Starting checker %r for %s",
 
347
                            command, self.name)
 
348
                # We don't need to redirect stdout and stderr, since
 
349
                # in normal mode, that is already done by daemon(),
 
350
                # and in debug mode we don't want to.  (Stdin is
 
351
                # always replaced by /dev/null.)
 
352
                self.checker = subprocess.Popen(command,
 
353
                                                close_fds=True,
 
354
                                                shell=True, cwd="/")
278
355
                self.checker_callback_tag = gobject.child_watch_add\
279
356
                                            (self.checker.pid,
280
357
                                             self.checker_callback)
281
 
            except subprocess.OSError, error:
 
358
            except OSError, error:
282
359
                logger.error(u"Failed to start subprocess: %s",
283
360
                             error)
284
361
        # Re-run this periodically if run by gobject.timeout_add
288
365
        if self.checker_callback_tag:
289
366
            gobject.source_remove(self.checker_callback_tag)
290
367
            self.checker_callback_tag = None
291
 
        if not hasattr(self, "checker") or self.checker is None:
 
368
        if getattr(self, "checker", None) is None:
292
369
            return
293
 
        logger.debug("Stopping checker for %(name)s", vars(self))
 
370
        logger.debug(u"Stopping checker for %(name)s", vars(self))
294
371
        try:
295
372
            os.kill(self.checker.pid, signal.SIGTERM)
296
373
            #os.sleep(0.5)
297
374
            #if self.checker.poll() is None:
298
375
            #    os.kill(self.checker.pid, signal.SIGKILL)
299
376
        except OSError, error:
300
 
            if error.errno != errno.ESRCH:
 
377
            if error.errno != errno.ESRCH: # No such process
301
378
                raise
302
379
        self.checker = None
303
 
    def still_valid(self, now=None):
 
380
    def still_valid(self):
304
381
        """Has the timeout not yet passed for this client?"""
305
 
        if now is None:
306
 
            now = datetime.datetime.now()
307
 
        if self.last_seen is None:
 
382
        now = datetime.datetime.now()
 
383
        if self.last_checked_ok is None:
308
384
            return now < (self.created + self.timeout)
309
385
        else:
310
 
            return now < (self.last_seen + self.timeout)
 
386
            return now < (self.last_checked_ok + self.timeout)
311
387
 
312
388
 
313
389
def peer_certificate(session):
329
405
 
330
406
def fingerprint(openpgp):
331
407
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
332
 
    # New empty GnuTLS certificate
333
 
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
334
 
    gnutls.library.functions.gnutls_openpgp_crt_init\
335
 
        (ctypes.byref(crt))
336
408
    # New GnuTLS "datum" with the OpenPGP public key
337
409
    datum = gnutls.library.types.gnutls_datum_t\
338
410
        (ctypes.cast(ctypes.c_char_p(openpgp),
339
411
                     ctypes.POINTER(ctypes.c_ubyte)),
340
412
         ctypes.c_uint(len(openpgp)))
 
413
    # New empty GnuTLS certificate
 
414
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
 
415
    gnutls.library.functions.gnutls_openpgp_crt_init\
 
416
        (ctypes.byref(crt))
341
417
    # Import the OpenPGP public key into the certificate
342
 
    ret = gnutls.library.functions.gnutls_openpgp_crt_import\
343
 
        (crt,
344
 
         ctypes.byref(datum),
345
 
         gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
 
418
    gnutls.library.functions.gnutls_openpgp_crt_import\
 
419
                    (crt, ctypes.byref(datum),
 
420
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
 
421
    # Verify the self signature in the key
 
422
    crtverify = ctypes.c_uint()
 
423
    gnutls.library.functions.gnutls_openpgp_crt_verify_self\
 
424
        (crt, 0, ctypes.byref(crtverify))
 
425
    if crtverify.value != 0:
 
426
        gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
 
427
        raise gnutls.errors.CertificateSecurityError("Verify failed")
346
428
    # New buffer for the fingerprint
347
 
    buffer = ctypes.create_string_buffer(20)
348
 
    buffer_length = ctypes.c_size_t()
 
429
    buf = ctypes.create_string_buffer(20)
 
430
    buf_len = ctypes.c_size_t()
349
431
    # Get the fingerprint from the certificate into the buffer
350
432
    gnutls.library.functions.gnutls_openpgp_crt_get_fingerprint\
351
 
        (crt, ctypes.byref(buffer), ctypes.byref(buffer_length))
 
433
        (crt, ctypes.byref(buf), ctypes.byref(buf_len))
352
434
    # Deinit the certificate
353
435
    gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
354
436
    # Convert the buffer to a Python bytestring
355
 
    fpr = ctypes.string_at(buffer, buffer_length.value)
 
437
    fpr = ctypes.string_at(buf, buf_len.value)
356
438
    # Convert the bytestring to hexadecimal notation
357
439
    hex_fpr = u''.join(u"%02X" % ord(char) for char in fpr)
358
440
    return hex_fpr
359
441
 
360
442
 
361
 
class tcp_handler(SocketServer.BaseRequestHandler, object):
 
443
class TCP_handler(SocketServer.BaseRequestHandler, object):
362
444
    """A TCP request handler class.
363
445
    Instantiated by IPv6_TCPServer for each request to handle it.
364
446
    Note: This will run in its own forked process."""
365
447
    
366
448
    def handle(self):
367
 
        logger.debug(u"TCP connection from: %s",
 
449
        logger.info(u"TCP connection from: %s",
368
450
                     unicode(self.client_address))
369
 
        session = gnutls.connection.ClientSession(self.request,
370
 
                                                  gnutls.connection.\
371
 
                                                  X509Credentials())
 
451
        session = gnutls.connection.ClientSession\
 
452
                  (self.request, gnutls.connection.X509Credentials())
 
453
        
 
454
        line = self.request.makefile().readline()
 
455
        logger.debug(u"Protocol version: %r", line)
 
456
        try:
 
457
            if int(line.strip().split()[0]) > 1:
 
458
                raise RuntimeError
 
459
        except (ValueError, IndexError, RuntimeError), error:
 
460
            logger.error(u"Unknown protocol version: %s", error)
 
461
            return
 
462
        
 
463
        # Note: gnutls.connection.X509Credentials is really a generic
 
464
        # GnuTLS certificate credentials object so long as no X.509
 
465
        # keys are added to it.  Therefore, we can use it here despite
 
466
        # using OpenPGP certificates.
372
467
        
373
468
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
374
469
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
375
470
        #                "+DHE-DSS"))
376
 
        priority = "NORMAL"
377
 
        if self.server.options.priority:
378
 
            priority = self.server.options.priority
 
471
        priority = "NORMAL"             # Fallback default, since this
 
472
                                        # MUST be set.
 
473
        if self.server.settings["priority"]:
 
474
            priority = self.server.settings["priority"]
379
475
        gnutls.library.functions.gnutls_priority_set_direct\
380
 
            (session._c_object, priority, None);
 
476
            (session._c_object, priority, None)
381
477
        
382
478
        try:
383
479
            session.handshake()
384
480
        except gnutls.errors.GNUTLSError, error:
385
 
            logger.debug(u"Handshake failed: %s", error)
 
481
            logger.warning(u"Handshake failed: %s", error)
386
482
            # Do not run session.bye() here: the session is not
387
483
            # established.  Just abandon the request.
388
484
            return
389
485
        try:
390
486
            fpr = fingerprint(peer_certificate(session))
391
487
        except (TypeError, gnutls.errors.GNUTLSError), error:
392
 
            logger.debug(u"Bad certificate: %s", error)
 
488
            logger.warning(u"Bad certificate: %s", error)
393
489
            session.bye()
394
490
            return
395
491
        logger.debug(u"Fingerprint: %s", fpr)
398
494
            if c.fingerprint == fpr:
399
495
                client = c
400
496
                break
 
497
        if not client:
 
498
            logger.warning(u"Client not found for fingerprint: %s",
 
499
                           fpr)
 
500
            session.bye()
 
501
            return
401
502
        # Have to check if client.still_valid(), since it is possible
402
503
        # that the client timed out while establishing the GnuTLS
403
504
        # session.
404
 
        if (not client) or (not client.still_valid()):
405
 
            if client:
406
 
                logger.debug(u"Client %(name)s is invalid",
407
 
                             vars(client))
408
 
            else:
409
 
                logger.debug(u"Client not found for fingerprint: %s",
410
 
                             fpr)
 
505
        if not client.still_valid():
 
506
            logger.warning(u"Client %(name)s is invalid",
 
507
                           vars(client))
411
508
            session.bye()
412
509
            return
413
510
        sent_size = 0
423
520
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
424
521
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
425
522
    Attributes:
426
 
        options:        Command line options
 
523
        settings:       Server settings
427
524
        clients:        Set() of Client objects
 
525
        enabled:        Boolean; whether this server is activated yet
428
526
    """
429
527
    address_family = socket.AF_INET6
430
528
    def __init__(self, *args, **kwargs):
431
 
        if "options" in kwargs:
432
 
            self.options = kwargs["options"]
433
 
            del kwargs["options"]
 
529
        if "settings" in kwargs:
 
530
            self.settings = kwargs["settings"]
 
531
            del kwargs["settings"]
434
532
        if "clients" in kwargs:
435
533
            self.clients = kwargs["clients"]
436
534
            del kwargs["clients"]
437
 
        return super(type(self), self).__init__(*args, **kwargs)
 
535
        self.enabled = False
 
536
        super(IPv6_TCPServer, self).__init__(*args, **kwargs)
438
537
    def server_bind(self):
439
538
        """This overrides the normal server_bind() function
440
539
        to bind to an interface if one was specified, and also NOT to
441
540
        bind to an address or port if they were not specified."""
442
 
        if self.options.interface:
443
 
            if not hasattr(socket, "SO_BINDTODEVICE"):
444
 
                # From /usr/include/asm-i486/socket.h
445
 
                socket.SO_BINDTODEVICE = 25
 
541
        if self.settings["interface"]:
 
542
            # 25 is from /usr/include/asm-i486/socket.h
 
543
            SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)
446
544
            try:
447
545
                self.socket.setsockopt(socket.SOL_SOCKET,
448
 
                                       socket.SO_BINDTODEVICE,
449
 
                                       self.options.interface)
 
546
                                       SO_BINDTODEVICE,
 
547
                                       self.settings["interface"])
450
548
            except socket.error, error:
451
549
                if error[0] == errno.EPERM:
452
 
                    logger.warning(u"No permission to"
453
 
                                   u" bind to interface %s",
454
 
                                   self.options.interface)
 
550
                    logger.error(u"No permission to"
 
551
                                 u" bind to interface %s",
 
552
                                 self.settings["interface"])
455
553
                else:
456
554
                    raise error
457
555
        # Only bind(2) the socket if we really need to.
460
558
                in6addr_any = "::"
461
559
                self.server_address = (in6addr_any,
462
560
                                       self.server_address[1])
463
 
            elif self.server_address[1] is None:
 
561
            elif not self.server_address[1]:
464
562
                self.server_address = (self.server_address[0],
465
563
                                       0)
466
 
            return super(type(self), self).server_bind()
 
564
#                 if self.settings["interface"]:
 
565
#                     self.server_address = (self.server_address[0],
 
566
#                                            0, # port
 
567
#                                            0, # flowinfo
 
568
#                                            if_nametoindex
 
569
#                                            (self.settings
 
570
#                                             ["interface"]))
 
571
            return super(IPv6_TCPServer, self).server_bind()
 
572
    def server_activate(self):
 
573
        if self.enabled:
 
574
            return super(IPv6_TCPServer, self).server_activate()
 
575
    def enable(self):
 
576
        self.enabled = True
467
577
 
468
578
 
469
579
def string_to_delta(interval):
479
589
    datetime.timedelta(1)
480
590
    >>> string_to_delta(u'1w')
481
591
    datetime.timedelta(7)
 
592
    >>> string_to_delta('5m 30s')
 
593
    datetime.timedelta(0, 330)
482
594
    """
483
 
    try:
484
 
        suffix=unicode(interval[-1])
485
 
        value=int(interval[:-1])
486
 
        if suffix == u"d":
487
 
            delta = datetime.timedelta(value)
488
 
        elif suffix == u"s":
489
 
            delta = datetime.timedelta(0, value)
490
 
        elif suffix == u"m":
491
 
            delta = datetime.timedelta(0, 0, 0, 0, value)
492
 
        elif suffix == u"h":
493
 
            delta = datetime.timedelta(0, 0, 0, 0, 0, value)
494
 
        elif suffix == u"w":
495
 
            delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
496
 
        else:
 
595
    timevalue = datetime.timedelta(0)
 
596
    for s in interval.split():
 
597
        try:
 
598
            suffix = unicode(s[-1])
 
599
            value = int(s[:-1])
 
600
            if suffix == u"d":
 
601
                delta = datetime.timedelta(value)
 
602
            elif suffix == u"s":
 
603
                delta = datetime.timedelta(0, value)
 
604
            elif suffix == u"m":
 
605
                delta = datetime.timedelta(0, 0, 0, 0, value)
 
606
            elif suffix == u"h":
 
607
                delta = datetime.timedelta(0, 0, 0, 0, 0, value)
 
608
            elif suffix == u"w":
 
609
                delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
 
610
            else:
 
611
                raise ValueError
 
612
        except (ValueError, IndexError):
497
613
            raise ValueError
498
 
    except (ValueError, IndexError):
499
 
        raise ValueError
500
 
    return delta
501
 
 
502
 
 
503
 
def add_service():
504
 
    """Derived from the Avahi example code"""
505
 
    global group, serviceName, serviceType, servicePort, serviceTXT, \
506
 
           domain, host
507
 
    if group is None:
508
 
        group = dbus.Interface(
509
 
                bus.get_object( avahi.DBUS_NAME,
510
 
                                server.EntryGroupNew()),
511
 
                avahi.DBUS_INTERFACE_ENTRY_GROUP)
512
 
        group.connect_to_signal('StateChanged',
513
 
                                entry_group_state_changed)
514
 
    logger.debug(u"Adding service '%s' of type '%s' ...",
515
 
                 serviceName, serviceType)
516
 
    
517
 
    group.AddService(
518
 
            serviceInterface,           # interface
519
 
            avahi.PROTO_INET6,          # protocol
520
 
            dbus.UInt32(0),             # flags
521
 
            serviceName, serviceType,
522
 
            domain, host,
523
 
            dbus.UInt16(servicePort),
524
 
            avahi.string_array_to_txt_array(serviceTXT))
525
 
    group.Commit()
526
 
 
527
 
 
528
 
def remove_service():
529
 
    """From the Avahi example code"""
530
 
    global group
531
 
    
532
 
    if not group is None:
533
 
        group.Reset()
 
614
        timevalue += delta
 
615
    return timevalue
534
616
 
535
617
 
536
618
def server_state_changed(state):
537
619
    """Derived from the Avahi example code"""
538
620
    if state == avahi.SERVER_COLLISION:
539
 
        logger.warning(u"Server name collision")
540
 
        remove_service()
 
621
        logger.error(u"Zeroconf server name collision")
 
622
        service.remove()
541
623
    elif state == avahi.SERVER_RUNNING:
542
 
        add_service()
 
624
        service.add()
543
625
 
544
626
 
545
627
def entry_group_state_changed(state, error):
546
628
    """Derived from the Avahi example code"""
547
 
    global serviceName, server, rename_count
548
 
    
549
 
    logger.debug(u"state change: %i", state)
 
629
    logger.debug(u"Avahi state change: %i", state)
550
630
    
551
631
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
552
 
        logger.debug(u"Service established.")
 
632
        logger.debug(u"Zeroconf service established.")
553
633
    elif state == avahi.ENTRY_GROUP_COLLISION:
554
 
        
555
 
        rename_count = rename_count - 1
556
 
        if rename_count > 0:
557
 
            name = server.GetAlternativeServiceName(name)
558
 
            logger.warning(u"Service name collision, "
559
 
                           u"changing name to '%s' ...", name)
560
 
            remove_service()
561
 
            add_service()
562
 
            
563
 
        else:
564
 
            logger.error(u"No suitable service name found after %i"
565
 
                         u" retries, exiting.", n_rename)
566
 
            killme(1)
 
634
        logger.warning(u"Zeroconf service name collision.")
 
635
        service.rename()
567
636
    elif state == avahi.ENTRY_GROUP_FAILURE:
568
 
        logger.error(u"Error in group state changed %s",
569
 
                     unicode(error))
570
 
        killme(1)
571
 
 
 
637
        logger.critical(u"Avahi: Error in group state changed %s",
 
638
                        unicode(error))
 
639
        raise AvahiGroupError("State changed: %s", str(error))
572
640
 
573
641
def if_nametoindex(interface):
574
 
    """Call the C function if_nametoindex()"""
 
642
    """Call the C function if_nametoindex(), or equivalent"""
 
643
    global if_nametoindex
575
644
    try:
576
 
        libc = ctypes.cdll.LoadLibrary("libc.so.6")
577
 
        return libc.if_nametoindex(interface)
 
645
        if_nametoindex = ctypes.cdll.LoadLibrary\
 
646
            (ctypes.util.find_library("c")).if_nametoindex
578
647
    except (OSError, AttributeError):
579
648
        if "struct" not in sys.modules:
580
649
            import struct
581
650
        if "fcntl" not in sys.modules:
582
651
            import fcntl
583
 
        SIOCGIFINDEX = 0x8933      # From /usr/include/linux/sockios.h
584
 
        s = socket.socket()
585
 
        ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
586
 
                            struct.pack("16s16x", interface))
587
 
        s.close()
588
 
        interface_index = struct.unpack("I", ifreq[16:20])[0]
589
 
        return interface_index
590
 
 
591
 
 
592
 
def daemon(nochdir, noclose):
 
652
        def if_nametoindex(interface):
 
653
            "Get an interface index the hard way, i.e. using fcntl()"
 
654
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
 
655
            s = socket.socket()
 
656
            ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
 
657
                                struct.pack("16s16x", interface))
 
658
            s.close()
 
659
            interface_index = struct.unpack("I", ifreq[16:20])[0]
 
660
            return interface_index
 
661
    return if_nametoindex(interface)
 
662
 
 
663
 
 
664
def daemon(nochdir = False, noclose = False):
593
665
    """See daemon(3).  Standard BSD Unix function.
594
666
    This should really exist as os.daemon, but it doesn't (yet)."""
595
667
    if os.fork():
597
669
    os.setsid()
598
670
    if not nochdir:
599
671
        os.chdir("/")
 
672
    if os.fork():
 
673
        sys.exit()
600
674
    if not noclose:
601
675
        # Close all standard open file descriptors
602
 
        null = os.open("/dev/null", os.O_NOCTTY | os.O_RDWR)
 
676
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
603
677
        if not stat.S_ISCHR(os.fstat(null).st_mode):
604
678
            raise OSError(errno.ENODEV,
605
679
                          "/dev/null not a character device")
610
684
            os.close(null)
611
685
 
612
686
 
613
 
def killme(status = 0):
614
 
    logger.debug("Stopping server with exit status %d", status)
615
 
    exitstatus = status
616
 
    if main_loop_started:
617
 
        main_loop.quit()
618
 
    else:
619
 
        sys.exit(status)
620
 
 
621
 
 
622
687
def main():
623
 
    global exitstatus
624
 
    exitstatus = 0
625
 
    global main_loop_started
626
 
    main_loop_started = False
627
 
    
628
 
    parser = OptionParser()
 
688
    parser = OptionParser(version = "%%prog %s" % version)
629
689
    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,
 
690
                      metavar="IF", help="Bind to interface IF")
 
691
    parser.add_option("-a", "--address", type="string",
633
692
                      help="Address to listen for requests on")
634
 
    parser.add_option("-p", "--port", type="int", default=None,
 
693
    parser.add_option("-p", "--port", type="int",
635
694
                      help="Port number to receive requests on")
636
695
    parser.add_option("--check", action="store_true", default=False,
637
696
                      help="Run self-test")
638
 
    parser.add_option("--debug", action="store_true", default=False,
639
 
                      help="Debug mode")
640
 
    parser.add_option("--priority", type="string",
641
 
                      default="SECURE256",
642
 
                      help="GnuTLS priority string"
643
 
                      " (see GnuTLS documentation)")
644
 
    parser.add_option("--servicename", type="string",
645
 
                      default="Mandos", help="Zeroconf service name")
646
 
    (options, args) = parser.parse_args()
 
697
    parser.add_option("--debug", action="store_true",
 
698
                      help="Debug mode; run in foreground and log to"
 
699
                      " terminal")
 
700
    parser.add_option("--priority", type="string", help="GnuTLS"
 
701
                      " priority string (see GnuTLS documentation)")
 
702
    parser.add_option("--servicename", type="string", metavar="NAME",
 
703
                      help="Zeroconf service name")
 
704
    parser.add_option("--configdir", type="string",
 
705
                      default="/etc/mandos", metavar="DIR",
 
706
                      help="Directory to search for configuration"
 
707
                      " files")
 
708
    options = parser.parse_args()[0]
647
709
    
648
710
    if options.check:
649
711
        import doctest
650
712
        doctest.testmod()
651
713
        sys.exit()
652
714
    
653
 
    # Parse config file
654
 
    defaults = { "timeout": "1h",
655
 
                 "interval": "5m",
656
 
                 "checker": "fping -q -- %%(fqdn)s",
657
 
                 }
658
 
    client_config = ConfigParser.SafeConfigParser(defaults)
659
 
    #client_config.readfp(open("global.conf"), "global.conf")
660
 
    client_config.read("mandos-clients.conf")
661
 
    
662
 
    global serviceName
663
 
    serviceName = options.servicename;
 
715
    # Default values for config file for server-global settings
 
716
    server_defaults = { "interface": "",
 
717
                        "address": "",
 
718
                        "port": "",
 
719
                        "debug": "False",
 
720
                        "priority":
 
721
                        "SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
 
722
                        "servicename": "Mandos",
 
723
                        }
 
724
    
 
725
    # Parse config file for server-global settings
 
726
    server_config = ConfigParser.SafeConfigParser(server_defaults)
 
727
    del server_defaults
 
728
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
 
729
    # Convert the SafeConfigParser object to a dict
 
730
    server_settings = server_config.defaults()
 
731
    # Use getboolean on the boolean config option
 
732
    server_settings["debug"] = server_config.getboolean\
 
733
                               ("DEFAULT", "debug")
 
734
    del server_config
 
735
    
 
736
    # Override the settings from the config file with command line
 
737
    # options, if set.
 
738
    for option in ("interface", "address", "port", "debug",
 
739
                   "priority", "servicename", "configdir"):
 
740
        value = getattr(options, option)
 
741
        if value is not None:
 
742
            server_settings[option] = value
 
743
    del options
 
744
    # Now we have our good server settings in "server_settings"
 
745
    
 
746
    debug = server_settings["debug"]
 
747
    
 
748
    if not debug:
 
749
        syslogger.setLevel(logging.WARNING)
 
750
        console.setLevel(logging.WARNING)
 
751
    
 
752
    if server_settings["servicename"] != "Mandos":
 
753
        syslogger.setFormatter(logging.Formatter\
 
754
                               ('Mandos (%s): %%(levelname)s:'
 
755
                                ' %%(message)s'
 
756
                                % server_settings["servicename"]))
 
757
    
 
758
    # Parse config file with clients
 
759
    client_defaults = { "timeout": "1h",
 
760
                        "interval": "5m",
 
761
                        "checker": "fping -q -- %(host)s",
 
762
                        "host": "",
 
763
                        }
 
764
    client_config = ConfigParser.SafeConfigParser(client_defaults)
 
765
    client_config.read(os.path.join(server_settings["configdir"],
 
766
                                    "clients.conf"))
 
767
    
 
768
    clients = Set()
 
769
    tcp_server = IPv6_TCPServer((server_settings["address"],
 
770
                                 server_settings["port"]),
 
771
                                TCP_handler,
 
772
                                settings=server_settings,
 
773
                                clients=clients)
 
774
    pidfilename = "/var/run/mandos.pid"
 
775
    try:
 
776
        pidfile = open(pidfilename, "w")
 
777
    except IOError, error:
 
778
        logger.error("Could not open file %r", pidfilename)
 
779
    
 
780
    uid = 65534
 
781
    gid = 65534
 
782
    try:
 
783
        uid = pwd.getpwnam("mandos").pw_uid
 
784
    except KeyError:
 
785
        try:
 
786
            uid = pwd.getpwnam("nobody").pw_uid
 
787
        except KeyError:
 
788
            pass
 
789
    try:
 
790
        gid = pwd.getpwnam("mandos").pw_gid
 
791
    except KeyError:
 
792
        try:
 
793
            gid = pwd.getpwnam("nogroup").pw_gid
 
794
        except KeyError:
 
795
            pass
 
796
    try:
 
797
        os.setuid(uid)
 
798
        os.setgid(gid)
 
799
    except OSError, error:
 
800
        if error[0] != errno.EPERM:
 
801
            raise error
 
802
    
 
803
    global service
 
804
    service = AvahiService(name = server_settings["servicename"],
 
805
                           servicetype = "_mandos._tcp", )
 
806
    if server_settings["interface"]:
 
807
        service.interface = if_nametoindex\
 
808
                            (server_settings["interface"])
664
809
    
665
810
    global main_loop
666
811
    global bus
669
814
    DBusGMainLoop(set_as_default=True )
670
815
    main_loop = gobject.MainLoop()
671
816
    bus = dbus.SystemBus()
672
 
    server = dbus.Interface(
673
 
            bus.get_object( avahi.DBUS_NAME, avahi.DBUS_PATH_SERVER ),
674
 
            avahi.DBUS_INTERFACE_SERVER )
 
817
    server = dbus.Interface(bus.get_object(avahi.DBUS_NAME,
 
818
                                           avahi.DBUS_PATH_SERVER),
 
819
                            avahi.DBUS_INTERFACE_SERVER)
675
820
    # End of Avahi example code
676
821
    
677
 
    debug = options.debug
678
 
    
679
 
    if debug:
680
 
        console = logging.StreamHandler()
681
 
        # console.setLevel(logging.DEBUG)
682
 
        console.setFormatter(logging.Formatter\
683
 
                             ('%(levelname)s: %(message)s'))
684
 
        logger.addHandler(console)
685
 
        del console
686
 
    
687
 
    clients = Set()
688
822
    def remove_from_clients(client):
689
823
        clients.remove(client)
690
824
        if not clients:
691
 
            logger.debug(u"No clients left, exiting")
692
 
            killme()
 
825
            logger.critical(u"No clients left, exiting")
 
826
            sys.exit()
693
827
    
694
 
    clients.update(Set(Client(name=section,
 
828
    clients.update(Set(Client(name = section,
695
829
                              stop_hook = remove_from_clients,
696
 
                              **(dict(client_config\
697
 
                                      .items(section))))
 
830
                              config
 
831
                              = dict(client_config.items(section)))
698
832
                       for section in client_config.sections()))
699
 
    
700
 
    if not debug:
701
 
        daemon(False, False)
 
833
    if not clients:
 
834
        logger.critical(u"No clients defined")
 
835
        sys.exit(1)
 
836
    
 
837
    if debug:
 
838
        # Redirect stdin so all checkers get /dev/null
 
839
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
 
840
        os.dup2(null, sys.stdin.fileno())
 
841
        if null > 2:
 
842
            os.close(null)
 
843
    else:
 
844
        # No console logging
 
845
        logger.removeHandler(console)
 
846
        # Close all input and output, do double fork, etc.
 
847
        daemon()
 
848
    
 
849
    try:
 
850
        pid = os.getpid()
 
851
        pidfile.write(str(pid) + "\n")
 
852
        pidfile.close()
 
853
        del pidfile
 
854
    except IOError:
 
855
        logger.error(u"Could not write to file %r with PID %d",
 
856
                     pidfilename, pid)
 
857
    except NameError:
 
858
        # "pidfile" was never created
 
859
        pass
 
860
    del pidfilename
702
861
    
703
862
    def cleanup():
704
863
        "Cleanup function; run on exit"
718
877
    
719
878
    if not debug:
720
879
        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())
 
880
    signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
 
881
    signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())
723
882
    
724
883
    for client in clients:
725
884
        client.start()
726
885
    
727
 
    tcp_server = IPv6_TCPServer((options.address, options.port),
728
 
                                tcp_handler,
729
 
                                options=options,
730
 
                                clients=clients)
731
 
    # Find out what random port we got
732
 
    global servicePort
733
 
    servicePort = tcp_server.socket.getsockname()[1]
734
 
    logger.debug(u"Now listening on port %d", servicePort)
735
 
    
736
 
    if options.interface is not None:
737
 
        global serviceInterface
738
 
        serviceInterface = if_nametoindex(options.interface)
739
 
    
740
 
    # From the Avahi example code
741
 
    server.connect_to_signal("StateChanged", server_state_changed)
742
 
    try:
743
 
        server_state_changed(server.GetState())
744
 
    except dbus.exceptions.DBusException, error:
745
 
        logger.critical(u"DBusException: %s", error)
746
 
        killme(1)
747
 
    # End of Avahi example code
748
 
    
749
 
    gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
750
 
                         lambda *args, **kwargs:
751
 
                         tcp_server.handle_request(*args[2:],
752
 
                                                   **kwargs) or True)
753
 
    try:
754
 
        logger.debug("Starting main loop")
755
 
        main_loop_started = True
 
886
    tcp_server.enable()
 
887
    tcp_server.server_activate()
 
888
    
 
889
    # Find out what port we got
 
890
    service.port = tcp_server.socket.getsockname()[1]
 
891
    logger.info(u"Now listening on address %r, port %d, flowinfo %d,"
 
892
                u" scope_id %d" % tcp_server.socket.getsockname())
 
893
    
 
894
    #service.interface = tcp_server.socket.getsockname()[3]
 
895
    
 
896
    try:
 
897
        # From the Avahi example code
 
898
        server.connect_to_signal("StateChanged", server_state_changed)
 
899
        try:
 
900
            server_state_changed(server.GetState())
 
901
        except dbus.exceptions.DBusException, error:
 
902
            logger.critical(u"DBusException: %s", error)
 
903
            sys.exit(1)
 
904
        # End of Avahi example code
 
905
        
 
906
        gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
 
907
                             lambda *args, **kwargs:
 
908
                             tcp_server.handle_request\
 
909
                             (*args[2:], **kwargs) or True)
 
910
        
 
911
        logger.debug(u"Starting main loop")
756
912
        main_loop.run()
 
913
    except AvahiError, error:
 
914
        logger.critical(u"AvahiError: %s" + unicode(error))
 
915
        sys.exit(1)
757
916
    except KeyboardInterrupt:
758
917
        if debug:
759
918
            print
760
 
    
761
 
    sys.exit(exitstatus)
762
919
 
763
920
if __name__ == '__main__':
764
921
    main()