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  • Committer: Teddy Hogeborn
  • Date: 2008-06-30 01:43:39 UTC
  • Revision ID: teddy@fukt.bsnet.se-20080630014339-rsuztydpl2w5ml83
* server.py: Rewritten to use Zeroconf (mDNS/DNS-SD) in place of the
             old broadcast-UDP-to-port-49001 method.

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#!/usr/bin/python
2
 
# -*- mode: python; coding: utf-8 -*-
3
 
4
 
# Mandos server - give out binary blobs to connecting clients.
5
 
6
 
# This program is partly derived from an example program for an Avahi
7
 
# service publisher, downloaded from
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".
12
 
13
 
# Everything else is
14
 
# Copyright © 2007-2008 Teddy Hogeborn & Björn Påhlsson
15
 
16
 
# This program is free software: you can redistribute it and/or modify
17
 
# it under the terms of the GNU General Public License as published by
18
 
# the Free Software Foundation, either version 3 of the License, or
19
 
# (at your option) any later version.
20
 
#
21
 
#     This program is distributed in the hope that it will be useful,
22
 
#     but WITHOUT ANY WARRANTY; without even the implied warranty of
23
 
#     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
24
 
#     GNU General Public License for more details.
25
 
26
 
# 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/>.
28
 
29
 
# Contact the authors at <mandos@fukt.bsnet.se>.
30
 
31
2
 
32
3
from __future__ import division
33
4
 
40
11
import gnutls.crypto
41
12
import gnutls.connection
42
13
import gnutls.errors
43
 
import gnutls.library.functions
44
 
import gnutls.library.constants
45
 
import gnutls.library.types
46
14
import ConfigParser
47
15
import sys
48
16
import re
50
18
import signal
51
19
from sets import Set
52
20
import subprocess
53
 
import atexit
54
 
import stat
55
 
import logging
56
 
import logging.handlers
57
21
 
58
22
import dbus
59
23
import gobject
60
24
import avahi
61
25
from dbus.mainloop.glib import DBusGMainLoop
62
 
import ctypes
63
 
 
64
 
version = "1.0"
65
 
 
66
 
logger = logging.Logger('mandos')
67
 
syslogger = logging.handlers.SysLogHandler\
68
 
            (facility = logging.handlers.SysLogHandler.LOG_DAEMON,
69
 
             address = "/dev/log")
70
 
syslogger.setFormatter(logging.Formatter\
71
 
                        ('Mandos: %(levelname)s: %(message)s'))
72
 
logger.addHandler(syslogger)
73
 
 
74
 
 
75
 
class AvahiError(Exception):
76
 
    def __init__(self, value):
77
 
        self.value = value
78
 
    def __str__(self):
79
 
        return repr(self.value)
80
 
 
81
 
class AvahiServiceError(AvahiError):
82
 
    pass
83
 
 
84
 
class AvahiGroupError(AvahiError):
85
 
    pass
86
 
 
87
 
 
88
 
class AvahiService(object):
89
 
    """An Avahi (Zeroconf) service.
90
 
    Attributes:
91
 
    interface: integer; avahi.IF_UNSPEC or an interface index.
92
 
               Used to optionally bind to the specified interface.
93
 
    name: string; Example: 'Mandos'
94
 
    type: string; Example: '_mandos._tcp'.
95
 
                  See <http://www.dns-sd.org/ServiceTypes.html>
96
 
    port: integer; what port to announce
97
 
    TXT: list of strings; TXT record for the service
98
 
    domain: string; Domain to publish on, default to .local if empty.
99
 
    host: string; Host to publish records for, default is localhost
100
 
    max_renames: integer; maximum number of renames
101
 
    rename_count: integer; counter so we only rename after collisions
102
 
                  a sensible number of times
103
 
    """
104
 
    def __init__(self, interface = avahi.IF_UNSPEC, name = None,
105
 
                 type = None, port = None, TXT = None, domain = "",
106
 
                 host = "", max_renames = 32768):
107
 
        self.interface = interface
108
 
        self.name = name
109
 
        self.type = type
110
 
        self.port = port
111
 
        if TXT is None:
112
 
            self.TXT = []
113
 
        else:
114
 
            self.TXT = TXT
115
 
        self.domain = domain
116
 
        self.host = host
117
 
        self.rename_count = 0
118
 
    def rename(self):
119
 
        """Derived from the Avahi example code"""
120
 
        if self.rename_count >= self.max_renames:
121
 
            logger.critical(u"No suitable service name found after %i"
122
 
                            u" retries, exiting.", rename_count)
123
 
            raise AvahiServiceError("Too many renames")
124
 
        name = server.GetAlternativeServiceName(name)
125
 
        logger.error(u"Changing name to %r ...", name)
126
 
        syslogger.setFormatter(logging.Formatter\
127
 
                               ('Mandos (%s): %%(levelname)s:'
128
 
                               ' %%(message)s' % name))
129
 
        self.remove()
130
 
        self.add()
131
 
        self.rename_count += 1
132
 
    def remove(self):
133
 
        """Derived from the Avahi example code"""
134
 
        if group is not None:
135
 
            group.Reset()
136
 
    def add(self):
137
 
        """Derived from the Avahi example code"""
138
 
        global group
139
 
        if group is None:
140
 
            group = dbus.Interface\
141
 
                    (bus.get_object(avahi.DBUS_NAME,
142
 
                                    server.EntryGroupNew()),
143
 
                     avahi.DBUS_INTERFACE_ENTRY_GROUP)
144
 
            group.connect_to_signal('StateChanged',
145
 
                                    entry_group_state_changed)
146
 
        logger.debug(u"Adding service '%s' of type '%s' ...",
147
 
                     service.name, service.type)
148
 
        group.AddService(
149
 
                self.interface,         # interface
150
 
                avahi.PROTO_INET6,      # protocol
151
 
                dbus.UInt32(0),         # flags
152
 
                self.name, self.type,
153
 
                self.domain, self.host,
154
 
                dbus.UInt16(self.port),
155
 
                avahi.string_array_to_txt_array(self.TXT))
156
 
        group.Commit()
157
 
 
158
 
# From the Avahi example code:
159
 
group = None                            # our entry group
 
26
 
 
27
# This variable is used to optionally bind to a specified
 
28
# interface.
 
29
serviceInterface = avahi.IF_UNSPEC
 
30
# It is a global variable to fit in with the rest of the
 
31
# variables from the Avahi server example code:
 
32
serviceName = "Mandos"
 
33
serviceType = "_mandos._tcp" # http://www.dns-sd.org/ServiceTypes.html
 
34
servicePort = None                      # Not known at startup
 
35
serviceTXT = []                         # TXT record for the service
 
36
domain = ""                  # Domain to publish on, default to .local
 
37
host = ""          # Host to publish records for, default to localhost
 
38
group = None #our entry group
 
39
rename_count = 12       # Counter so we only rename after collisions a
 
40
                        # sensible number of times
160
41
# End of Avahi example code
161
42
 
162
43
 
163
44
class Client(object):
164
45
    """A representation of a client host served by this server.
165
46
    Attributes:
166
 
    name:      string; from the config file, used in log messages
167
 
    fingerprint: string (40 or 32 hexadecimal digits); used to
168
 
                 uniquely identify the client
169
 
    secret:    bytestring; sent verbatim (over TLS) to client
170
 
    host:      string; available for use by the checker command
171
 
    created:   datetime.datetime(); object creation, not client host
172
 
    last_checked_ok: datetime.datetime() or None if not yet checked OK
173
 
    timeout:   datetime.timedelta(); How long from last_checked_ok
174
 
                                     until this client is invalid
 
47
    password:  string
 
48
    fqdn:      string, FQDN (used by the checker)
 
49
    created:   datetime.datetime()
 
50
    last_seen: datetime.datetime() or None if not yet seen
 
51
    timeout:   datetime.timedelta(); How long from last_seen until
 
52
                                     this client is invalid
175
53
    interval:  datetime.timedelta(); How often to start a new checker
 
54
    timeout_milliseconds: Used by gobject.timeout_add()
 
55
    interval_milliseconds: - '' -
176
56
    stop_hook: If set, called by stop() as stop_hook(self)
177
57
    checker:   subprocess.Popen(); a running checker process used
178
58
                                   to see if the client lives.
179
 
                                   'None' if no process is running.
 
59
                                   Is None if no process is running.
180
60
    checker_initiator_tag: a gobject event source tag, or None
181
61
    stop_initiator_tag:    - '' -
182
62
    checker_callback_tag:  - '' -
183
 
    checker_command: string; External command which is run to check if
184
 
                     client lives.  %() expansions are done at
185
 
                     runtime with vars(self) as dict, so that for
186
 
                     instance %(name)s can be used in the command.
187
 
    Private attibutes:
188
 
    _timeout: Real variable for 'timeout'
189
 
    _interval: Real variable for 'interval'
190
 
    _timeout_milliseconds: Used when calling gobject.timeout_add()
191
 
    _interval_milliseconds: - '' -
192
63
    """
193
 
    def _set_timeout(self, timeout):
194
 
        "Setter function for 'timeout' attribute"
195
 
        self._timeout = timeout
196
 
        self._timeout_milliseconds = ((self.timeout.days
 
64
    def __init__(self, name=None, options=None, stop_hook=None,
 
65
                 dn=None, password=None, passfile=None, fqdn=None,
 
66
                 timeout=None, interval=-1):
 
67
        self.name = name
 
68
        self.dn = dn
 
69
        if password:
 
70
            self.password = password
 
71
        elif passfile:
 
72
            self.password = open(passfile).readall()
 
73
        else:
 
74
            raise RuntimeError(u"No Password or Passfile for client %s"
 
75
                               % self.name)
 
76
        self.fqdn = fqdn                # string
 
77
        self.created = datetime.datetime.now()
 
78
        self.last_seen = None
 
79
        if timeout is None:
 
80
            timeout = options.timeout
 
81
        self.timeout = timeout
 
82
        self.timeout_milliseconds = ((self.timeout.days
 
83
                                      * 24 * 60 * 60 * 1000)
 
84
                                     + (self.timeout.seconds * 1000)
 
85
                                     + (self.timeout.microseconds
 
86
                                        // 1000))
 
87
        if interval == -1:
 
88
            interval = options.interval
 
89
        else:
 
90
            interval = string_to_delta(interval)
 
91
        self.interval = interval
 
92
        self.interval_milliseconds = ((self.interval.days
197
93
                                       * 24 * 60 * 60 * 1000)
198
 
                                      + (self.timeout.seconds * 1000)
199
 
                                      + (self.timeout.microseconds
 
94
                                      + (self.interval.seconds * 1000)
 
95
                                      + (self.interval.microseconds
200
96
                                         // 1000))
201
 
    timeout = property(lambda self: self._timeout,
202
 
                       _set_timeout)
203
 
    del _set_timeout
204
 
    def _set_interval(self, interval):
205
 
        "Setter function for 'interval' attribute"
206
 
        self._interval = interval
207
 
        self._interval_milliseconds = ((self.interval.days
208
 
                                        * 24 * 60 * 60 * 1000)
209
 
                                       + (self.interval.seconds
210
 
                                          * 1000)
211
 
                                       + (self.interval.microseconds
212
 
                                          // 1000))
213
 
    interval = property(lambda self: self._interval,
214
 
                        _set_interval)
215
 
    del _set_interval
216
 
    def __init__(self, name = None, stop_hook=None, config={}):
217
 
        """Note: the 'checker' key in 'config' sets the
218
 
        'checker_command' attribute and *not* the 'checker'
219
 
        attribute."""
220
 
        self.name = name
221
 
        logger.debug(u"Creating client %r", self.name)
222
 
        # Uppercase and remove spaces from fingerprint for later
223
 
        # comparison purposes with return value from the fingerprint()
224
 
        # function
225
 
        self.fingerprint = config["fingerprint"].upper()\
226
 
                           .replace(u" ", u"")
227
 
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
228
 
        if "secret" in config:
229
 
            self.secret = config["secret"].decode(u"base64")
230
 
        elif "secfile" in config:
231
 
            sf = open(config["secfile"])
232
 
            self.secret = sf.read()
233
 
            sf.close()
234
 
        else:
235
 
            raise TypeError(u"No secret or secfile for client %s"
236
 
                            % self.name)
237
 
        self.host = config.get("host", "")
238
 
        self.created = datetime.datetime.now()
239
 
        self.last_checked_ok = None
240
 
        self.timeout = string_to_delta(config["timeout"])
241
 
        self.interval = string_to_delta(config["interval"])
242
97
        self.stop_hook = stop_hook
243
98
        self.checker = None
244
99
        self.checker_initiator_tag = None
245
100
        self.stop_initiator_tag = None
246
101
        self.checker_callback_tag = None
247
 
        self.check_command = config["checker"]
248
102
    def start(self):
249
 
        """Start this client's checker and timeout hooks"""
 
103
        """Start this clients checker and timeout hooks"""
250
104
        # Schedule a new checker to be started an 'interval' from now,
251
105
        # and every interval from then on.
252
 
        self.checker_initiator_tag = gobject.timeout_add\
253
 
                                     (self._interval_milliseconds,
254
 
                                      self.start_checker)
 
106
        self.checker_initiator_tag = gobject.\
 
107
                                     timeout_add(self.interval_milliseconds,
 
108
                                                 self.start_checker)
255
109
        # Also start a new checker *right now*.
256
110
        self.start_checker()
257
111
        # Schedule a stop() when 'timeout' has passed
258
 
        self.stop_initiator_tag = gobject.timeout_add\
259
 
                                  (self._timeout_milliseconds,
260
 
                                   self.stop)
 
112
        self.stop_initiator_tag = gobject.\
 
113
                                     timeout_add(self.timeout_milliseconds,
 
114
                                                 self.stop)
261
115
    def stop(self):
262
116
        """Stop this client.
263
 
        The possibility that a client might be restarted is left open,
264
 
        but not currently used."""
265
 
        # If this client doesn't have a secret, it is already stopped.
266
 
        if hasattr(self, "secret") and self.secret:
267
 
            logger.info(u"Stopping client %s", self.name)
268
 
            self.secret = None
269
 
        else:
270
 
            return False
271
 
        if getattr(self, "stop_initiator_tag", False):
 
117
        The possibility that this client might be restarted is left
 
118
        open, but not currently used."""
 
119
        # print "Stopping client", self.name
 
120
        self.password = None
 
121
        if self.stop_initiator_tag:
272
122
            gobject.source_remove(self.stop_initiator_tag)
273
123
            self.stop_initiator_tag = None
274
 
        if getattr(self, "checker_initiator_tag", False):
 
124
        if self.checker_initiator_tag:
275
125
            gobject.source_remove(self.checker_initiator_tag)
276
126
            self.checker_initiator_tag = None
277
127
        self.stop_checker()
280
130
        # Do not run this again if called by a gobject.timeout_add
281
131
        return False
282
132
    def __del__(self):
283
 
        self.stop_hook = None
284
 
        self.stop()
 
133
        # Some code duplication here and in stop()
 
134
        if hasattr(self, "stop_initiator_tag") \
 
135
               and self.stop_initiator_tag:
 
136
            gobject.source_remove(self.stop_initiator_tag)
 
137
            self.stop_initiator_tag = None
 
138
        if hasattr(self, "checker_initiator_tag") \
 
139
               and self.checker_initiator_tag:
 
140
            gobject.source_remove(self.checker_initiator_tag)
 
141
            self.checker_initiator_tag = None
 
142
        self.stop_checker()
285
143
    def checker_callback(self, pid, condition):
286
144
        """The checker has completed, so take appropriate actions."""
287
145
        now = datetime.datetime.now()
288
 
        self.checker_callback_tag = None
289
 
        self.checker = None
290
146
        if os.WIFEXITED(condition) \
291
147
               and (os.WEXITSTATUS(condition) == 0):
292
 
            logger.info(u"Checker for %(name)s succeeded",
293
 
                        vars(self))
294
 
            self.last_checked_ok = now
 
148
            #print "Checker for %(name)s succeeded" % vars(self)
 
149
            self.last_seen = now
295
150
            gobject.source_remove(self.stop_initiator_tag)
296
 
            self.stop_initiator_tag = gobject.timeout_add\
297
 
                                      (self._timeout_milliseconds,
298
 
                                       self.stop)
299
 
        elif not os.WIFEXITED(condition):
300
 
            logger.warning(u"Checker for %(name)s crashed?",
301
 
                           vars(self))
302
 
        else:
303
 
            logger.info(u"Checker for %(name)s failed",
304
 
                        vars(self))
 
151
            self.stop_initiator_tag = gobject.\
 
152
                                      timeout_add(self.timeout_milliseconds,
 
153
                                                  self.stop)
 
154
        #else:
 
155
        #    if not os.WIFEXITED(condition):
 
156
        #        print "Checker for %(name)s crashed?" % vars(self)
 
157
        #    else:
 
158
        #        print "Checker for %(name)s failed" % vars(self)
 
159
        self.checker = None
 
160
        self.checker_callback_tag = None
305
161
    def start_checker(self):
306
162
        """Start a new checker subprocess if one is not running.
307
163
        If a checker already exists, leave it running and do
308
164
        nothing."""
309
 
        # The reason for not killing a running checker is that if we
310
 
        # did that, then if a checker (for some reason) started
311
 
        # running slowly and taking more than 'interval' time, the
312
 
        # client would inevitably timeout, since no checker would get
313
 
        # a chance to run to completion.  If we instead leave running
314
 
        # checkers alone, the checker would have to take more time
315
 
        # than 'timeout' for the client to be declared invalid, which
316
 
        # is as it should be.
317
165
        if self.checker is None:
318
 
            try:
319
 
                # In case check_command has exactly one % operator
320
 
                command = self.check_command % self.host
321
 
            except TypeError:
322
 
                # Escape attributes for the shell
323
 
                escaped_attrs = dict((key, re.escape(str(val)))
324
 
                                     for key, val in
325
 
                                     vars(self).iteritems())
326
 
                try:
327
 
                    command = self.check_command % escaped_attrs
328
 
                except TypeError, error:
329
 
                    logger.error(u'Could not format string "%s":'
330
 
                                 u' %s', self.check_command, error)
331
 
                    return True # Try again later
332
 
            try:
333
 
                logger.info(u"Starting checker %r for %s",
334
 
                            command, self.name)
335
 
                self.checker = subprocess.Popen(command,
336
 
                                                close_fds=True,
337
 
                                                shell=True, cwd="/")
338
 
                self.checker_callback_tag = gobject.child_watch_add\
339
 
                                            (self.checker.pid,
340
 
                                             self.checker_callback)
 
166
            #print "Starting checker for", self.name
 
167
            try:
 
168
                self.checker = subprocess.\
 
169
                               Popen("sleep 1; fping -q -- %s"
 
170
                                     % re.escape(self.fqdn),
 
171
                                     stdout=subprocess.PIPE,
 
172
                                     close_fds=True, shell=True,
 
173
                                     cwd="/")
 
174
                self.checker_callback_tag = gobject.\
 
175
                                            child_watch_add(self.checker.pid,
 
176
                                                            self.\
 
177
                                                            checker_callback)
341
178
            except subprocess.OSError, error:
342
 
                logger.error(u"Failed to start subprocess: %s",
343
 
                             error)
 
179
                sys.stderr.write(u"Failed to start subprocess: %s\n"
 
180
                                 % error)
344
181
        # Re-run this periodically if run by gobject.timeout_add
345
182
        return True
346
183
    def stop_checker(self):
347
184
        """Force the checker process, if any, to stop."""
348
 
        if self.checker_callback_tag:
349
 
            gobject.source_remove(self.checker_callback_tag)
350
 
            self.checker_callback_tag = None
351
 
        if getattr(self, "checker", None) is None:
 
185
        if not hasattr(self, "checker") or self.checker is None:
352
186
            return
353
 
        logger.debug(u"Stopping checker for %(name)s", vars(self))
354
 
        try:
355
 
            os.kill(self.checker.pid, signal.SIGTERM)
356
 
            #os.sleep(0.5)
357
 
            #if self.checker.poll() is None:
358
 
            #    os.kill(self.checker.pid, signal.SIGKILL)
359
 
        except OSError, error:
360
 
            if error.errno != errno.ESRCH: # No such process
361
 
                raise
 
187
        gobject.source_remove(self.checker_callback_tag)
 
188
        self.checker_callback_tag = None
 
189
        os.kill(self.checker.pid, signal.SIGTERM)
 
190
        if self.checker.poll() is None:
 
191
            os.kill(self.checker.pid, signal.SIGKILL)
362
192
        self.checker = None
363
 
    def still_valid(self):
 
193
    def still_valid(self, now=None):
364
194
        """Has the timeout not yet passed for this client?"""
365
 
        now = datetime.datetime.now()
366
 
        if self.last_checked_ok is None:
 
195
        if now is None:
 
196
            now = datetime.datetime.now()
 
197
        if self.last_seen is None:
367
198
            return now < (self.created + self.timeout)
368
199
        else:
369
 
            return now < (self.last_checked_ok + self.timeout)
370
 
 
371
 
 
372
 
def peer_certificate(session):
373
 
    "Return the peer's OpenPGP certificate as a bytestring"
374
 
    # If not an OpenPGP certificate...
375
 
    if gnutls.library.functions.gnutls_certificate_type_get\
376
 
            (session._c_object) \
377
 
           != gnutls.library.constants.GNUTLS_CRT_OPENPGP:
378
 
        # ...do the normal thing
379
 
        return session.peer_certificate
380
 
    list_size = ctypes.c_uint()
381
 
    cert_list = gnutls.library.functions.gnutls_certificate_get_peers\
382
 
        (session._c_object, ctypes.byref(list_size))
383
 
    if list_size.value == 0:
384
 
        return None
385
 
    cert = cert_list[0]
386
 
    return ctypes.string_at(cert.data, cert.size)
387
 
 
388
 
 
389
 
def fingerprint(openpgp):
390
 
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
391
 
    # New GnuTLS "datum" with the OpenPGP public key
392
 
    datum = gnutls.library.types.gnutls_datum_t\
393
 
        (ctypes.cast(ctypes.c_char_p(openpgp),
394
 
                     ctypes.POINTER(ctypes.c_ubyte)),
395
 
         ctypes.c_uint(len(openpgp)))
396
 
    # New empty GnuTLS certificate
397
 
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
398
 
    gnutls.library.functions.gnutls_openpgp_crt_init\
399
 
        (ctypes.byref(crt))
400
 
    # Import the OpenPGP public key into the certificate
401
 
    gnutls.library.functions.gnutls_openpgp_crt_import\
402
 
                    (crt, ctypes.byref(datum),
403
 
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
404
 
    # New buffer for the fingerprint
405
 
    buffer = ctypes.create_string_buffer(20)
406
 
    buffer_length = ctypes.c_size_t()
407
 
    # Get the fingerprint from the certificate into the buffer
408
 
    gnutls.library.functions.gnutls_openpgp_crt_get_fingerprint\
409
 
        (crt, ctypes.byref(buffer), ctypes.byref(buffer_length))
410
 
    # Deinit the certificate
411
 
    gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
412
 
    # Convert the buffer to a Python bytestring
413
 
    fpr = ctypes.string_at(buffer, buffer_length.value)
414
 
    # Convert the bytestring to hexadecimal notation
415
 
    hex_fpr = u''.join(u"%02X" % ord(char) for char in fpr)
416
 
    return hex_fpr
 
200
            return now < (self.last_seen + self.timeout)
417
201
 
418
202
 
419
203
class tcp_handler(SocketServer.BaseRequestHandler, object):
420
204
    """A TCP request handler class.
421
205
    Instantiated by IPv6_TCPServer for each request to handle it.
422
206
    Note: This will run in its own forked process."""
423
 
    
424
207
    def handle(self):
425
 
        logger.info(u"TCP connection from: %s",
426
 
                     unicode(self.client_address))
427
 
        session = gnutls.connection.ClientSession\
428
 
                  (self.request, gnutls.connection.X509Credentials())
429
 
        
430
 
        line = self.request.makefile().readline()
431
 
        logger.debug(u"Protocol version: %r", line)
432
 
        try:
433
 
            if int(line.strip().split()[0]) > 1:
434
 
                raise RuntimeError
435
 
        except (ValueError, IndexError, RuntimeError), error:
436
 
            logger.error(u"Unknown protocol version: %s", error)
437
 
            return
438
 
        
439
 
        # Note: gnutls.connection.X509Credentials is really a generic
440
 
        # GnuTLS certificate credentials object so long as no X.509
441
 
        # keys are added to it.  Therefore, we can use it here despite
442
 
        # using OpenPGP certificates.
443
 
        
444
 
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
445
 
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
446
 
        #                "+DHE-DSS"))
447
 
        priority = "NORMAL"             # Fallback default, since this
448
 
                                        # MUST be set.
449
 
        if self.server.settings["priority"]:
450
 
            priority = self.server.settings["priority"]
451
 
        gnutls.library.functions.gnutls_priority_set_direct\
452
 
            (session._c_object, priority, None);
453
 
        
 
208
        #print u"TCP request came"
 
209
        #print u"Request:", self.request
 
210
        #print u"Client Address:", self.client_address
 
211
        #print u"Server:", self.server
 
212
        session = gnutls.connection.ServerSession(self.request,
 
213
                                                  self.server\
 
214
                                                  .credentials)
454
215
        try:
455
216
            session.handshake()
456
217
        except gnutls.errors.GNUTLSError, error:
457
 
            logger.warning(u"Handshake failed: %s", error)
 
218
            #sys.stderr.write(u"Handshake failed: %s\n" % error)
458
219
            # Do not run session.bye() here: the session is not
459
220
            # established.  Just abandon the request.
460
221
            return
 
222
        #if session.peer_certificate:
 
223
        #    print "DN:", session.peer_certificate.subject
461
224
        try:
462
 
            fpr = fingerprint(peer_certificate(session))
463
 
        except (TypeError, gnutls.errors.GNUTLSError), error:
464
 
            logger.warning(u"Bad certificate: %s", error)
 
225
            session.verify_peer()
 
226
        except gnutls.errors.CertificateError, error:
 
227
            #sys.stderr.write(u"Verify failed: %s\n" % error)
465
228
            session.bye()
466
229
            return
467
 
        logger.debug(u"Fingerprint: %s", fpr)
468
230
        client = None
469
 
        for c in self.server.clients:
470
 
            if c.fingerprint == fpr:
 
231
        for c in clients:
 
232
            if c.dn == session.peer_certificate.subject:
471
233
                client = c
472
234
                break
473
 
        if not client:
474
 
            logger.warning(u"Client not found for fingerprint: %s",
475
 
                           fpr)
476
 
            session.bye()
477
 
            return
478
235
        # Have to check if client.still_valid(), since it is possible
479
236
        # that the client timed out while establishing the GnuTLS
480
237
        # session.
481
 
        if not client.still_valid():
482
 
            logger.warning(u"Client %(name)s is invalid",
483
 
                           vars(client))
484
 
            session.bye()
485
 
            return
486
 
        sent_size = 0
487
 
        while sent_size < len(client.secret):
488
 
            sent = session.send(client.secret[sent_size:])
489
 
            logger.debug(u"Sent: %d, remaining: %d",
490
 
                         sent, len(client.secret)
491
 
                         - (sent_size + sent))
492
 
            sent_size += sent
 
238
        if client and client.still_valid():
 
239
            session.send(client.password)
 
240
        else:
 
241
            #if client:
 
242
            #    sys.stderr.write(u"Client %(name)s is invalid\n"
 
243
            #                     % vars(client))
 
244
            #else:
 
245
            #    sys.stderr.write(u"Client not found for DN: %s\n"
 
246
            #                     % session.peer_certificate.subject)
 
247
            #session.send("gazonk")
 
248
            pass
493
249
        session.bye()
494
250
 
495
251
 
496
252
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
497
253
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
498
254
    Attributes:
499
 
        settings:       Server settings
 
255
        options:        Command line options
500
256
        clients:        Set() of Client objects
 
257
        credentials:    GnuTLS X.509 credentials
501
258
    """
502
259
    address_family = socket.AF_INET6
503
260
    def __init__(self, *args, **kwargs):
504
 
        if "settings" in kwargs:
505
 
            self.settings = kwargs["settings"]
506
 
            del kwargs["settings"]
 
261
        if "options" in kwargs:
 
262
            self.options = kwargs["options"]
 
263
            del kwargs["options"]
507
264
        if "clients" in kwargs:
508
265
            self.clients = kwargs["clients"]
509
266
            del kwargs["clients"]
 
267
        if "credentials" in kwargs:
 
268
            self.credentials = kwargs["credentials"]
 
269
            del kwargs["credentials"]
510
270
        return super(type(self), self).__init__(*args, **kwargs)
511
271
    def server_bind(self):
512
272
        """This overrides the normal server_bind() function
513
273
        to bind to an interface if one was specified, and also NOT to
514
274
        bind to an address or port if they were not specified."""
515
 
        if self.settings["interface"]:
516
 
            # 25 is from /usr/include/asm-i486/socket.h
517
 
            SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)
 
275
        if self.options.interface:
 
276
            if not hasattr(socket, "SO_BINDTODEVICE"):
 
277
                # From /usr/include/asm-i486/socket.h
 
278
                socket.SO_BINDTODEVICE = 25
518
279
            try:
519
280
                self.socket.setsockopt(socket.SOL_SOCKET,
520
 
                                       SO_BINDTODEVICE,
521
 
                                       self.settings["interface"])
 
281
                                       socket.SO_BINDTODEVICE,
 
282
                                       self.options.interface)
522
283
            except socket.error, error:
523
284
                if error[0] == errno.EPERM:
524
 
                    logger.error(u"No permission to"
525
 
                                 u" bind to interface %s",
526
 
                                 self.settings["interface"])
 
285
                    sys.stderr.write(u"Warning: No permission to bind to interface %s\n"
 
286
                                     % self.options.interface)
527
287
                else:
528
288
                    raise error
529
289
        # Only bind(2) the socket if we really need to.
532
292
                in6addr_any = "::"
533
293
                self.server_address = (in6addr_any,
534
294
                                       self.server_address[1])
535
 
            elif not self.server_address[1]:
 
295
            elif self.server_address[1] is None:
536
296
                self.server_address = (self.server_address[0],
537
297
                                       0)
538
 
#                 if self.settings["interface"]:
539
 
#                     self.server_address = (self.server_address[0],
540
 
#                                            0, # port
541
 
#                                            0, # flowinfo
542
 
#                                            if_nametoindex
543
 
#                                            (self.settings
544
 
#                                             ["interface"]))
545
298
            return super(type(self), self).server_bind()
546
299
 
547
300
 
579
332
    return delta
580
333
 
581
334
 
 
335
def add_service():
 
336
    """From the Avahi server example code"""
 
337
    global group, serviceName, serviceType, servicePort, serviceTXT, \
 
338
           domain, host
 
339
    if group is None:
 
340
        group = dbus.Interface(
 
341
                bus.get_object( avahi.DBUS_NAME,
 
342
                                server.EntryGroupNew()),
 
343
                avahi.DBUS_INTERFACE_ENTRY_GROUP)
 
344
        group.connect_to_signal('StateChanged',
 
345
                                entry_group_state_changed)
 
346
    
 
347
    # print "Adding service '%s' of type '%s' ..." % (serviceName,
 
348
    #                                                 serviceType)
 
349
    
 
350
    group.AddService(
 
351
            serviceInterface,           # interface
 
352
            avahi.PROTO_INET6,          # protocol
 
353
            dbus.UInt32(0),             # flags
 
354
            serviceName, serviceType,
 
355
            domain, host,
 
356
            dbus.UInt16(servicePort),
 
357
            avahi.string_array_to_txt_array(serviceTXT))
 
358
    group.Commit()
 
359
 
 
360
 
 
361
def remove_service():
 
362
    """From the Avahi server example code"""
 
363
    global group
 
364
    
 
365
    if not group is None:
 
366
        group.Reset()
 
367
 
 
368
 
582
369
def server_state_changed(state):
583
 
    """Derived from the Avahi example code"""
 
370
    """From the Avahi server example code"""
584
371
    if state == avahi.SERVER_COLLISION:
585
 
        logger.error(u"Server name collision")
586
 
        service.remove()
 
372
        print "WARNING: Server name collision"
 
373
        remove_service()
587
374
    elif state == avahi.SERVER_RUNNING:
588
 
        service.add()
 
375
        add_service()
589
376
 
590
377
 
591
378
def entry_group_state_changed(state, error):
592
 
    """Derived from the Avahi example code"""
593
 
    logger.debug(u"state change: %i", state)
 
379
    """From the Avahi server example code"""
 
380
    global serviceName, server, rename_count
 
381
    
 
382
    # print "state change: %i" % state
594
383
    
595
384
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
596
 
        logger.debug(u"Service established.")
 
385
        pass
 
386
        # print "Service established."
597
387
    elif state == avahi.ENTRY_GROUP_COLLISION:
598
 
        logger.warning(u"Service name collision.")
599
 
        service.rename()
 
388
        
 
389
        rename_count = rename_count - 1
 
390
        if rename_count > 0:
 
391
            name = server.GetAlternativeServiceName(name)
 
392
            print "WARNING: Service name collision, changing name to '%s' ..." % name
 
393
            remove_service()
 
394
            add_service()
 
395
            
 
396
        else:
 
397
            print "ERROR: No suitable service name found after %i retries, exiting." % n_rename
 
398
            main_loop.quit()
600
399
    elif state == avahi.ENTRY_GROUP_FAILURE:
601
 
        logger.critical(u"Error in group state changed %s",
602
 
                        unicode(error))
603
 
        raise AvahiGroupError("State changed: %s", str(error))
 
400
        print "Error in group state changed", error
 
401
        main_loop.quit()
 
402
        return
 
403
 
604
404
 
605
405
def if_nametoindex(interface):
606
 
    """Call the C function if_nametoindex(), or equivalent"""
607
 
    global if_nametoindex
 
406
    """Call the C function if_nametoindex()"""
608
407
    try:
609
 
        if "ctypes.util" not in sys.modules:
610
 
            import ctypes.util
611
 
        if_nametoindex = ctypes.cdll.LoadLibrary\
612
 
            (ctypes.util.find_library("c")).if_nametoindex
613
 
    except (OSError, AttributeError):
 
408
        if "ctypes" not in sys.modules:
 
409
            import ctypes
 
410
        libc = ctypes.cdll.LoadLibrary("libc.so.6")
 
411
        return libc.if_nametoindex(interface)
 
412
    except (ImportError, OSError, AttributeError):
614
413
        if "struct" not in sys.modules:
615
414
            import struct
616
415
        if "fcntl" not in sys.modules:
617
416
            import fcntl
618
 
        def if_nametoindex(interface):
619
 
            "Get an interface index the hard way, i.e. using fcntl()"
620
 
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
621
 
            s = socket.socket()
622
 
            ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
623
 
                                struct.pack("16s16x", interface))
624
 
            s.close()
625
 
            interface_index = struct.unpack("I", ifreq[16:20])[0]
626
 
            return interface_index
627
 
    return if_nametoindex(interface)
628
 
 
629
 
 
630
 
def daemon(nochdir = False, noclose = False):
631
 
    """See daemon(3).  Standard BSD Unix function.
632
 
    This should really exist as os.daemon, but it doesn't (yet)."""
633
 
    if os.fork():
634
 
        sys.exit()
635
 
    os.setsid()
636
 
    if not nochdir:
637
 
        os.chdir("/")
638
 
    if os.fork():
639
 
        sys.exit()
640
 
    if not noclose:
641
 
        # Close all standard open file descriptors
642
 
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
643
 
        if not stat.S_ISCHR(os.fstat(null).st_mode):
644
 
            raise OSError(errno.ENODEV,
645
 
                          "/dev/null not a character device")
646
 
        os.dup2(null, sys.stdin.fileno())
647
 
        os.dup2(null, sys.stdout.fileno())
648
 
        os.dup2(null, sys.stderr.fileno())
649
 
        if null > 2:
650
 
            os.close(null)
651
 
 
652
 
 
653
 
def main():
654
 
    global main_loop_started
655
 
    main_loop_started = False
656
 
    
657
 
    parser = OptionParser(version = "Mandos server %s" % version)
 
417
        SIOCGIFINDEX = 0x8933      # From /usr/include/linux/sockios.h
 
418
        s = socket.socket()
 
419
        ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
 
420
                            struct.pack("16s16x", interface))
 
421
        s.close()
 
422
        interface_index = struct.unpack("I", ifreq[16:20])[0]
 
423
        return interface_index
 
424
 
 
425
 
 
426
if __name__ == '__main__':
 
427
    parser = OptionParser()
658
428
    parser.add_option("-i", "--interface", type="string",
659
 
                      metavar="IF", help="Bind to interface IF")
660
 
    parser.add_option("-a", "--address", type="string",
661
 
                      help="Address to listen for requests on")
662
 
    parser.add_option("-p", "--port", type="int",
 
429
                      default=None, metavar="IF",
 
430
                      help="Bind to interface IF")
 
431
    parser.add_option("--cert", type="string", default="cert.pem",
 
432
                      metavar="FILE",
 
433
                      help="Public key certificate PEM file to use")
 
434
    parser.add_option("--key", type="string", default="key.pem",
 
435
                      metavar="FILE",
 
436
                      help="Private key PEM file to use")
 
437
    parser.add_option("--ca", type="string", default="ca.pem",
 
438
                      metavar="FILE",
 
439
                      help="Certificate Authority certificate PEM file to use")
 
440
    parser.add_option("--crl", type="string", default="crl.pem",
 
441
                      metavar="FILE",
 
442
                      help="Certificate Revokation List PEM file to use")
 
443
    parser.add_option("-p", "--port", type="int", default=None,
663
444
                      help="Port number to receive requests on")
 
445
    parser.add_option("--timeout", type="string", # Parsed later
 
446
                      default="1h",
 
447
                      help="Amount of downtime allowed for clients")
 
448
    parser.add_option("--interval", type="string", # Parsed later
 
449
                      default="5m",
 
450
                      help="How often to check that a client is up")
664
451
    parser.add_option("--check", action="store_true", default=False,
665
452
                      help="Run self-test")
666
 
    parser.add_option("--debug", action="store_true",
667
 
                      help="Debug mode; run in foreground and log to"
668
 
                      " terminal")
669
 
    parser.add_option("--priority", type="string", help="GnuTLS"
670
 
                      " priority string (see GnuTLS documentation)")
671
 
    parser.add_option("--servicename", type="string", metavar="NAME",
672
 
                      help="Zeroconf service name")
673
 
    parser.add_option("--configdir", type="string",
674
 
                      default="/etc/mandos", metavar="DIR",
675
 
                      help="Directory to search for configuration"
676
 
                      " files")
677
453
    (options, args) = parser.parse_args()
678
454
    
679
455
    if options.check:
681
457
        doctest.testmod()
682
458
        sys.exit()
683
459
    
684
 
    # Default values for config file for server-global settings
685
 
    server_defaults = { "interface": "",
686
 
                        "address": "",
687
 
                        "port": "",
688
 
                        "debug": "False",
689
 
                        "priority":
690
 
                        "SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
691
 
                        "servicename": "Mandos",
692
 
                        }
693
 
    
694
 
    # Parse config file for server-global settings
695
 
    server_config = ConfigParser.SafeConfigParser(server_defaults)
696
 
    del server_defaults
697
 
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
698
 
    server_section = "server"
699
 
    # Convert the SafeConfigParser object to a dict
700
 
    server_settings = dict(server_config.items(server_section))
701
 
    # Use getboolean on the boolean config option
702
 
    server_settings["debug"] = server_config.getboolean\
703
 
                               (server_section, "debug")
704
 
    del server_config
705
 
    
706
 
    # Override the settings from the config file with command line
707
 
    # options, if set.
708
 
    for option in ("interface", "address", "port", "debug",
709
 
                   "priority", "servicename", "configdir"):
710
 
        value = getattr(options, option)
711
 
        if value is not None:
712
 
            server_settings[option] = value
713
 
    del options
714
 
    # Now we have our good server settings in "server_settings"
715
 
    
716
 
    debug = server_settings["debug"]
717
 
    
718
 
    if not debug:
719
 
        syslogger.setLevel(logging.WARNING)
720
 
    
721
 
    if server_settings["servicename"] != "Mandos":
722
 
        syslogger.setFormatter(logging.Formatter\
723
 
                               ('Mandos (%s): %%(levelname)s:'
724
 
                                ' %%(message)s'
725
 
                                % server_settings["servicename"]))
726
 
    
727
 
    # Parse config file with clients
728
 
    client_defaults = { "timeout": "1h",
729
 
                        "interval": "5m",
730
 
                        "checker": "fping -q -- %%(host)s",
731
 
                        }
732
 
    client_config = ConfigParser.SafeConfigParser(client_defaults)
733
 
    client_config.read(os.path.join(server_settings["configdir"],
734
 
                                    "clients.conf"))
735
 
    
736
 
    global service
737
 
    service = AvahiService(name = server_settings["servicename"],
738
 
                           type = "_mandos._tcp", );
739
 
    if server_settings["interface"]:
740
 
        service.interface = if_nametoindex(server_settings["interface"])
741
 
    
742
 
    global main_loop
743
 
    global bus
744
 
    global server
745
 
    # From the Avahi example code
 
460
    # Parse the time arguments
 
461
    try:
 
462
        options.timeout = string_to_delta(options.timeout)
 
463
    except ValueError:
 
464
        parser.error("option --timeout: Unparseable time")
 
465
    try:
 
466
        options.interval = string_to_delta(options.interval)
 
467
    except ValueError:
 
468
        parser.error("option --interval: Unparseable time")
 
469
    
 
470
    cert = gnutls.crypto.X509Certificate(open(options.cert).read())
 
471
    key = gnutls.crypto.X509PrivateKey(open(options.key).read())
 
472
    ca = gnutls.crypto.X509Certificate(open(options.ca).read())
 
473
    crl = gnutls.crypto.X509CRL(open(options.crl).read())
 
474
    cred = gnutls.connection.X509Credentials(cert, key, [ca], [crl])
 
475
    
 
476
    # Parse config file
 
477
    defaults = {}
 
478
    client_config = ConfigParser.SafeConfigParser(defaults)
 
479
    #client_config.readfp(open("secrets.conf"), "secrets.conf")
 
480
    client_config.read("mandos-clients.conf")
 
481
    
 
482
    # From the Avahi server example code
746
483
    DBusGMainLoop(set_as_default=True )
747
484
    main_loop = gobject.MainLoop()
748
485
    bus = dbus.SystemBus()
751
488
            avahi.DBUS_INTERFACE_SERVER )
752
489
    # End of Avahi example code
753
490
    
754
 
    if debug:
755
 
        console = logging.StreamHandler()
756
 
        # console.setLevel(logging.DEBUG)
757
 
        console.setFormatter(logging.Formatter\
758
 
                             ('%(levelname)s: %(message)s'))
759
 
        logger.addHandler(console)
760
 
        del console
761
 
    
762
491
    clients = Set()
763
492
    def remove_from_clients(client):
764
493
        clients.remove(client)
765
494
        if not clients:
766
 
            logger.critical(u"No clients left, exiting")
767
 
            sys.exit()
 
495
            print "No clients left, exiting"
 
496
            main_loop.quit()
768
497
    
769
 
    clients.update(Set(Client(name = section,
 
498
    clients.update(Set(Client(name=section, options=options,
770
499
                              stop_hook = remove_from_clients,
771
 
                              config
772
 
                              = dict(client_config.items(section)))
 
500
                              **(dict(client_config\
 
501
                                      .items(section))))
773
502
                       for section in client_config.sections()))
774
 
    if not clients:
775
 
        logger.critical(u"No clients defined")
776
 
        sys.exit(1)
777
 
    
778
 
    if not debug:
779
 
        daemon()
780
 
    
781
 
    pidfilename = "/var/run/mandos/mandos.pid"
782
 
    pid = os.getpid()
783
 
    try:
784
 
        pidfile = open(pidfilename, "w")
785
 
        pidfile.write(str(pid) + "\n")
786
 
        pidfile.close()
787
 
        del pidfile
788
 
    except IOError, err:
789
 
        logger.error(u"Could not write %s file with PID %d",
790
 
                     pidfilename, os.getpid())
791
 
    
792
 
    def cleanup():
793
 
        "Cleanup function; run on exit"
794
 
        global group
795
 
        # From the Avahi example code
796
 
        if not group is None:
797
 
            group.Free()
798
 
            group = None
799
 
        # End of Avahi example code
800
 
        
801
 
        while clients:
802
 
            client = clients.pop()
803
 
            client.stop_hook = None
804
 
            client.stop()
805
 
    
806
 
    atexit.register(cleanup)
807
 
    
808
 
    if not debug:
809
 
        signal.signal(signal.SIGINT, signal.SIG_IGN)
810
 
    signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
811
 
    signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())
812
 
    
813
503
    for client in clients:
814
504
        client.start()
815
505
    
816
 
    tcp_server = IPv6_TCPServer((server_settings["address"],
817
 
                                 server_settings["port"]),
 
506
    tcp_server = IPv6_TCPServer((None, options.port),
818
507
                                tcp_handler,
819
 
                                settings=server_settings,
820
 
                                clients=clients)
821
 
    # Find out what port we got
822
 
    service.port = tcp_server.socket.getsockname()[1]
823
 
    logger.info(u"Now listening on address %r, port %d, flowinfo %d,"
824
 
                u" scope_id %d" % tcp_server.socket.getsockname())
825
 
    
826
 
    #service.interface = tcp_server.socket.getsockname()[3]
827
 
    
 
508
                                options=options,
 
509
                                clients=clients,
 
510
                                credentials=cred)
 
511
    # Find out what random port we got
 
512
    servicePort = tcp_server.socket.getsockname()[1]
 
513
    #sys.stderr.write("Now listening on port %d\n" % servicePort)
 
514
    
 
515
    if options.interface is not None:
 
516
        serviceInterface = if_nametoindex(options.interface)
 
517
    
 
518
    # From the Avahi server example code
 
519
    server.connect_to_signal("StateChanged", server_state_changed)
 
520
    server_state_changed(server.GetState())
 
521
    # End of Avahi example code
 
522
    
 
523
    gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
 
524
                         lambda *args, **kwargs:
 
525
                         tcp_server.handle_request(*args[2:],
 
526
                                                   **kwargs) or True)
828
527
    try:
829
 
        # From the Avahi example code
830
 
        server.connect_to_signal("StateChanged", server_state_changed)
831
 
        try:
832
 
            server_state_changed(server.GetState())
833
 
        except dbus.exceptions.DBusException, error:
834
 
            logger.critical(u"DBusException: %s", error)
835
 
            sys.exit(1)
836
 
        # End of Avahi example code
837
 
        
838
 
        gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
839
 
                             lambda *args, **kwargs:
840
 
                             tcp_server.handle_request\
841
 
                             (*args[2:], **kwargs) or True)
842
 
        
843
 
        logger.debug(u"Starting main loop")
844
 
        main_loop_started = True
845
528
        main_loop.run()
846
 
    except AvahiError, error:
847
 
        logger.critical(u"AvahiError: %s" + unicode(error))
848
 
        sys.exit(1)
849
529
    except KeyboardInterrupt:
850
 
        if debug:
851
 
            print
 
530
        print
 
531
    
 
532
    # Cleanup here
852
533
 
853
 
if __name__ == '__main__':
854
 
    main()
 
534
    # From the Avahi server example code
 
535
    if not group is None:
 
536
        group.Free()
 
537
    # End of Avahi example code
 
538
    
 
539
    for client in clients:
 
540
        client.stop_hook = None
 
541
        client.stop()