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Fixed fallback on error in mandos-client
fixed a bug in password-request

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mandos
1
1
#!/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
# 
2
31
 
3
32
from __future__ import division
4
33
 
21
50
import signal
22
51
from sets import Set
23
52
import subprocess
 
53
import atexit
 
54
import stat
 
55
import logging
 
56
import logging.handlers
24
57
 
25
58
import dbus
26
59
import gobject
28
61
from dbus.mainloop.glib import DBusGMainLoop
29
62
import ctypes
30
63
 
31
 
import logging
32
 
import logging.handlers
33
 
 
34
 
# logghandler.setFormatter(logging.Formatter('%(levelname)s %(message)s')
 
64
version = "1.0"
35
65
 
36
66
logger = logging.Logger('mandos')
37
 
logger.addHandler(logging.handlers.SysLogHandler(facility = logging.handlers.SysLogHandler.LOG_DAEMON))
38
 
 
39
 
# This variable is used to optionally bind to a specified interface.
40
 
# It is a global variable to fit in with the other variables from the
41
 
# Avahi server example code.
42
 
serviceInterface = avahi.IF_UNSPEC
43
 
# From the Avahi server example code:
44
 
serviceName = "Mandos"
45
 
serviceType = "_mandos._tcp" # http://www.dns-sd.org/ServiceTypes.html
46
 
servicePort = None                      # Not known at startup
47
 
serviceTXT = []                         # TXT record for the service
48
 
domain = ""                  # Domain to publish on, default to .local
49
 
host = ""          # Host to publish records for, default to localhost
50
 
group = None #our entry group
51
 
rename_count = 12       # Counter so we only rename after collisions a
52
 
                        # sensible number of times
 
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
console = logging.StreamHandler()
 
75
console.setFormatter(logging.Formatter('%(name)s: %(levelname)s:'
 
76
                                       ' %(message)s'))
 
77
logger.addHandler(console)
 
78
 
 
79
class AvahiError(Exception):
 
80
    def __init__(self, value):
 
81
        self.value = value
 
82
    def __str__(self):
 
83
        return repr(self.value)
 
84
 
 
85
class AvahiServiceError(AvahiError):
 
86
    pass
 
87
 
 
88
class AvahiGroupError(AvahiError):
 
89
    pass
 
90
 
 
91
 
 
92
class AvahiService(object):
 
93
    """An Avahi (Zeroconf) service.
 
94
    Attributes:
 
95
    interface: integer; avahi.IF_UNSPEC or an interface index.
 
96
               Used to optionally bind to the specified interface.
 
97
    name: string; Example: 'Mandos'
 
98
    type: string; Example: '_mandos._tcp'.
 
99
                  See <http://www.dns-sd.org/ServiceTypes.html>
 
100
    port: integer; what port to announce
 
101
    TXT: list of strings; TXT record for the service
 
102
    domain: string; Domain to publish on, default to .local if empty.
 
103
    host: string; Host to publish records for, default is localhost
 
104
    max_renames: integer; maximum number of renames
 
105
    rename_count: integer; counter so we only rename after collisions
 
106
                  a sensible number of times
 
107
    """
 
108
    def __init__(self, interface = avahi.IF_UNSPEC, name = None,
 
109
                 type = None, port = None, TXT = None, domain = "",
 
110
                 host = "", max_renames = 32768):
 
111
        self.interface = interface
 
112
        self.name = name
 
113
        self.type = type
 
114
        self.port = port
 
115
        if TXT is None:
 
116
            self.TXT = []
 
117
        else:
 
118
            self.TXT = TXT
 
119
        self.domain = domain
 
120
        self.host = host
 
121
        self.rename_count = 0
 
122
    def rename(self):
 
123
        """Derived from the Avahi example code"""
 
124
        if self.rename_count >= self.max_renames:
 
125
            logger.critical(u"No suitable service name found after %i"
 
126
                            u" retries, exiting.", rename_count)
 
127
            raise AvahiServiceError("Too many renames")
 
128
        name = server.GetAlternativeServiceName(name)
 
129
        logger.error(u"Changing name to %r ...", name)
 
130
        syslogger.setFormatter(logging.Formatter\
 
131
                               ('Mandos (%s): %%(levelname)s:'
 
132
                               ' %%(message)s' % name))
 
133
        self.remove()
 
134
        self.add()
 
135
        self.rename_count += 1
 
136
    def remove(self):
 
137
        """Derived from the Avahi example code"""
 
138
        if group is not None:
 
139
            group.Reset()
 
140
    def add(self):
 
141
        """Derived from the Avahi example code"""
 
142
        global group
 
143
        if group is None:
 
144
            group = dbus.Interface\
 
145
                    (bus.get_object(avahi.DBUS_NAME,
 
146
                                    server.EntryGroupNew()),
 
147
                     avahi.DBUS_INTERFACE_ENTRY_GROUP)
 
148
            group.connect_to_signal('StateChanged',
 
149
                                    entry_group_state_changed)
 
150
        logger.debug(u"Adding service '%s' of type '%s' ...",
 
151
                     service.name, service.type)
 
152
        group.AddService(
 
153
                self.interface,         # interface
 
154
                avahi.PROTO_INET6,      # protocol
 
155
                dbus.UInt32(0),         # flags
 
156
                self.name, self.type,
 
157
                self.domain, self.host,
 
158
                dbus.UInt16(self.port),
 
159
                avahi.string_array_to_txt_array(self.TXT))
 
160
        group.Commit()
 
161
 
 
162
# From the Avahi example code:
 
163
group = None                            # our entry group
53
164
# End of Avahi example code
54
165
 
55
166
 
60
171
    fingerprint: string (40 or 32 hexadecimal digits); used to
61
172
                 uniquely identify the client
62
173
    secret:    bytestring; sent verbatim (over TLS) to client
63
 
    fqdn:      string (FQDN); available for use by the checker command
64
 
    created:   datetime.datetime()
65
 
    last_seen: datetime.datetime() or None if not yet seen
66
 
    timeout:   datetime.timedelta(); How long from last_seen until
67
 
                                     this client is invalid
 
174
    host:      string; available for use by the checker command
 
175
    created:   datetime.datetime(); object creation, not client host
 
176
    last_checked_ok: datetime.datetime() or None if not yet checked OK
 
177
    timeout:   datetime.timedelta(); How long from last_checked_ok
 
178
                                     until this client is invalid
68
179
    interval:  datetime.timedelta(); How often to start a new checker
69
180
    stop_hook: If set, called by stop() as stop_hook(self)
70
181
    checker:   subprocess.Popen(); a running checker process used
71
182
                                   to see if the client lives.
72
 
                                   Is None if no process is running.
 
183
                                   'None' if no process is running.
73
184
    checker_initiator_tag: a gobject event source tag, or None
74
185
    stop_initiator_tag:    - '' -
75
186
    checker_callback_tag:  - '' -
76
187
    checker_command: string; External command which is run to check if
77
 
                     client lives.  %()s expansions are done at
 
188
                     client lives.  %() expansions are done at
78
189
                     runtime with vars(self) as dict, so that for
79
190
                     instance %(name)s can be used in the command.
80
191
    Private attibutes:
81
192
    _timeout: Real variable for 'timeout'
82
193
    _interval: Real variable for 'interval'
83
 
    _timeout_milliseconds: Used by gobject.timeout_add()
 
194
    _timeout_milliseconds: Used when calling gobject.timeout_add()
84
195
    _interval_milliseconds: - '' -
85
196
    """
86
197
    def _set_timeout(self, timeout):
106
217
    interval = property(lambda self: self._interval,
107
218
                        _set_interval)
108
219
    del _set_interval
109
 
    def __init__(self, name=None, options=None, stop_hook=None,
110
 
                 fingerprint=None, secret=None, secfile=None, fqdn=None,
111
 
                 timeout=None, interval=-1, checker=None):
 
220
    def __init__(self, name = None, stop_hook=None, config={}):
 
221
        """Note: the 'checker' key in 'config' sets the
 
222
        'checker_command' attribute and *not* the 'checker'
 
223
        attribute."""
112
224
        self.name = name
113
 
        # Uppercase and remove spaces from fingerprint
114
 
        # for later comparison purposes with return value of
115
 
        # the fingerprint() function
116
 
        self.fingerprint = fingerprint.upper().replace(u" ", u"")
117
 
        if secret:
118
 
            self.secret = secret.decode(u"base64")
119
 
        elif secfile:
120
 
            sf = open(secfile)
 
225
        logger.debug(u"Creating client %r", self.name)
 
226
        # Uppercase and remove spaces from fingerprint for later
 
227
        # comparison purposes with return value from the fingerprint()
 
228
        # function
 
229
        self.fingerprint = config["fingerprint"].upper()\
 
230
                           .replace(u" ", u"")
 
231
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
 
232
        if "secret" in config:
 
233
            self.secret = config["secret"].decode(u"base64")
 
234
        elif "secfile" in config:
 
235
            sf = open(config["secfile"])
121
236
            self.secret = sf.read()
122
237
            sf.close()
123
238
        else:
124
 
            raise RuntimeError(u"No secret or secfile for client %s"
125
 
                               % self.name)
126
 
        self.fqdn = fqdn                # string
 
239
            raise TypeError(u"No secret or secfile for client %s"
 
240
                            % self.name)
 
241
        self.host = config.get("host", "")
127
242
        self.created = datetime.datetime.now()
128
 
        self.last_seen = None
129
 
        if timeout is None:
130
 
            timeout = options.timeout
131
 
        self.timeout = timeout
132
 
        if interval == -1:
133
 
            interval = options.interval
134
 
        else:
135
 
            interval = string_to_delta(interval)
136
 
        self.interval = interval
 
243
        self.last_checked_ok = None
 
244
        self.timeout = string_to_delta(config["timeout"])
 
245
        self.interval = string_to_delta(config["interval"])
137
246
        self.stop_hook = stop_hook
138
247
        self.checker = None
139
248
        self.checker_initiator_tag = None
140
249
        self.stop_initiator_tag = None
141
250
        self.checker_callback_tag = None
142
 
        self.check_command = checker
 
251
        self.check_command = config["checker"]
143
252
    def start(self):
144
 
        """Start this clients checker and timeout hooks"""
 
253
        """Start this client's checker and timeout hooks"""
145
254
        # Schedule a new checker to be started an 'interval' from now,
146
255
        # and every interval from then on.
147
256
        self.checker_initiator_tag = gobject.timeout_add\
155
264
                                   self.stop)
156
265
    def stop(self):
157
266
        """Stop this client.
158
 
        The possibility that this client might be restarted is left
159
 
        open, but not currently used."""
160
 
        logger.debug(u"Stopping client %s", self.name)
161
 
        self.secret = None
162
 
        if self.stop_initiator_tag:
 
267
        The possibility that a client might be restarted is left open,
 
268
        but not currently used."""
 
269
        # If this client doesn't have a secret, it is already stopped.
 
270
        if hasattr(self, "secret") and self.secret:
 
271
            logger.info(u"Stopping client %s", self.name)
 
272
            self.secret = None
 
273
        else:
 
274
            return False
 
275
        if getattr(self, "stop_initiator_tag", False):
163
276
            gobject.source_remove(self.stop_initiator_tag)
164
277
            self.stop_initiator_tag = None
165
 
        if self.checker_initiator_tag:
 
278
        if getattr(self, "checker_initiator_tag", False):
166
279
            gobject.source_remove(self.checker_initiator_tag)
167
280
            self.checker_initiator_tag = None
168
281
        self.stop_checker()
171
284
        # Do not run this again if called by a gobject.timeout_add
172
285
        return False
173
286
    def __del__(self):
174
 
        # Some code duplication here and in stop()
175
 
        if hasattr(self, "stop_initiator_tag") \
176
 
               and self.stop_initiator_tag:
177
 
            gobject.source_remove(self.stop_initiator_tag)
178
 
            self.stop_initiator_tag = None
179
 
        if hasattr(self, "checker_initiator_tag") \
180
 
               and self.checker_initiator_tag:
181
 
            gobject.source_remove(self.checker_initiator_tag)
182
 
            self.checker_initiator_tag = None
183
 
        self.stop_checker()
 
287
        self.stop_hook = None
 
288
        self.stop()
184
289
    def checker_callback(self, pid, condition):
185
290
        """The checker has completed, so take appropriate actions."""
186
291
        now = datetime.datetime.now()
 
292
        self.checker_callback_tag = None
 
293
        self.checker = None
187
294
        if os.WIFEXITED(condition) \
188
295
               and (os.WEXITSTATUS(condition) == 0):
189
 
            logger.debug(u"Checker for %(name)s succeeded",
190
 
                         vars(self))
191
 
            self.last_seen = now
 
296
            logger.info(u"Checker for %(name)s succeeded",
 
297
                        vars(self))
 
298
            self.last_checked_ok = now
192
299
            gobject.source_remove(self.stop_initiator_tag)
193
300
            self.stop_initiator_tag = gobject.timeout_add\
194
301
                                      (self._timeout_milliseconds,
195
302
                                       self.stop)
196
 
        if not os.WIFEXITED(condition):
 
303
        elif not os.WIFEXITED(condition):
197
304
            logger.warning(u"Checker for %(name)s crashed?",
198
305
                           vars(self))
199
306
        else:
200
 
            logger.debug(u"Checker for %(name)s failed",
201
 
                         vars(self))
202
 
            self.checker = None
203
 
        self.checker_callback_tag = None
 
307
            logger.info(u"Checker for %(name)s failed",
 
308
                        vars(self))
204
309
    def start_checker(self):
205
310
        """Start a new checker subprocess if one is not running.
206
311
        If a checker already exists, leave it running and do
207
312
        nothing."""
 
313
        # The reason for not killing a running checker is that if we
 
314
        # did that, then if a checker (for some reason) started
 
315
        # running slowly and taking more than 'interval' time, the
 
316
        # client would inevitably timeout, since no checker would get
 
317
        # a chance to run to completion.  If we instead leave running
 
318
        # checkers alone, the checker would have to take more time
 
319
        # than 'timeout' for the client to be declared invalid, which
 
320
        # is as it should be.
208
321
        if self.checker is None:
209
 
            logger.debug(u"Starting checker for %s",
210
 
                         self.name)
211
322
            try:
212
 
                command = self.check_command % self.fqdn
 
323
                # In case check_command has exactly one % operator
 
324
                command = self.check_command % self.host
213
325
            except TypeError:
 
326
                # Escape attributes for the shell
214
327
                escaped_attrs = dict((key, re.escape(str(val)))
215
328
                                     for key, val in
216
329
                                     vars(self).iteritems())
217
330
                try:
218
331
                    command = self.check_command % escaped_attrs
219
332
                except TypeError, error:
220
 
                    logger.critical(u'Could not format string "%s": %s',
221
 
                                    self.check_command, error)
 
333
                    logger.error(u'Could not format string "%s":'
 
334
                                 u' %s', self.check_command, error)
222
335
                    return True # Try again later
223
336
            try:
224
 
                self.checker = subprocess.\
225
 
                               Popen(command,
226
 
                                     stdout=subprocess.PIPE,
227
 
                                     close_fds=True, shell=True,
228
 
                                     cwd="/")
229
 
                self.checker_callback_tag = gobject.\
230
 
                                            child_watch_add(self.checker.pid,
231
 
                                                            self.\
232
 
                                                            checker_callback)
 
337
                logger.info(u"Starting checker %r for %s",
 
338
                            command, self.name)
 
339
                self.checker = subprocess.Popen(command,
 
340
                                                close_fds=True,
 
341
                                                shell=True, cwd="/")
 
342
                self.checker_callback_tag = gobject.child_watch_add\
 
343
                                            (self.checker.pid,
 
344
                                             self.checker_callback)
233
345
            except subprocess.OSError, error:
234
346
                logger.error(u"Failed to start subprocess: %s",
235
347
                             error)
237
349
        return True
238
350
    def stop_checker(self):
239
351
        """Force the checker process, if any, to stop."""
240
 
        if not hasattr(self, "checker") or self.checker is None:
 
352
        if self.checker_callback_tag:
 
353
            gobject.source_remove(self.checker_callback_tag)
 
354
            self.checker_callback_tag = None
 
355
        if getattr(self, "checker", None) is None:
241
356
            return
242
 
        gobject.source_remove(self.checker_callback_tag)
243
 
        self.checker_callback_tag = None
244
 
        os.kill(self.checker.pid, signal.SIGTERM)
245
 
        if self.checker.poll() is None:
246
 
            os.kill(self.checker.pid, signal.SIGKILL)
 
357
        logger.debug(u"Stopping checker for %(name)s", vars(self))
 
358
        try:
 
359
            os.kill(self.checker.pid, signal.SIGTERM)
 
360
            #os.sleep(0.5)
 
361
            #if self.checker.poll() is None:
 
362
            #    os.kill(self.checker.pid, signal.SIGKILL)
 
363
        except OSError, error:
 
364
            if error.errno != errno.ESRCH: # No such process
 
365
                raise
247
366
        self.checker = None
248
 
    def still_valid(self, now=None):
 
367
    def still_valid(self):
249
368
        """Has the timeout not yet passed for this client?"""
250
 
        if now is None:
251
 
            now = datetime.datetime.now()
252
 
        if self.last_seen is None:
 
369
        now = datetime.datetime.now()
 
370
        if self.last_checked_ok is None:
253
371
            return now < (self.created + self.timeout)
254
372
        else:
255
 
            return now < (self.last_seen + self.timeout)
 
373
            return now < (self.last_checked_ok + self.timeout)
256
374
 
257
375
 
258
376
def peer_certificate(session):
 
377
    "Return the peer's OpenPGP certificate as a bytestring"
259
378
    # If not an OpenPGP certificate...
260
379
    if gnutls.library.functions.gnutls_certificate_type_get\
261
380
            (session._c_object) \
272
391
 
273
392
 
274
393
def fingerprint(openpgp):
275
 
    # New empty GnuTLS certificate
276
 
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
277
 
    gnutls.library.functions.gnutls_openpgp_crt_init\
278
 
        (ctypes.byref(crt))
 
394
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
279
395
    # New GnuTLS "datum" with the OpenPGP public key
280
396
    datum = gnutls.library.types.gnutls_datum_t\
281
397
        (ctypes.cast(ctypes.c_char_p(openpgp),
282
398
                     ctypes.POINTER(ctypes.c_ubyte)),
283
399
         ctypes.c_uint(len(openpgp)))
 
400
    # New empty GnuTLS certificate
 
401
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
 
402
    gnutls.library.functions.gnutls_openpgp_crt_init\
 
403
        (ctypes.byref(crt))
284
404
    # Import the OpenPGP public key into the certificate
285
 
    ret = gnutls.library.functions.gnutls_openpgp_crt_import\
286
 
        (crt,
287
 
         ctypes.byref(datum),
288
 
         gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
 
405
    gnutls.library.functions.gnutls_openpgp_crt_import\
 
406
                    (crt, ctypes.byref(datum),
 
407
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
289
408
    # New buffer for the fingerprint
290
409
    buffer = ctypes.create_string_buffer(20)
291
410
    buffer_length = ctypes.c_size_t()
307
426
    Note: This will run in its own forked process."""
308
427
    
309
428
    def handle(self):
310
 
        logger.debug(u"TCP connection from: %s",
 
429
        logger.info(u"TCP connection from: %s",
311
430
                     unicode(self.client_address))
312
 
        session = gnutls.connection.ClientSession(self.request,
313
 
                                                  gnutls.connection.\
314
 
                                                  X509Credentials())
 
431
        session = gnutls.connection.ClientSession\
 
432
                  (self.request, gnutls.connection.X509Credentials())
 
433
        
 
434
        line = self.request.makefile().readline()
 
435
        logger.debug(u"Protocol version: %r", line)
 
436
        try:
 
437
            if int(line.strip().split()[0]) > 1:
 
438
                raise RuntimeError
 
439
        except (ValueError, IndexError, RuntimeError), error:
 
440
            logger.error(u"Unknown protocol version: %s", error)
 
441
            return
 
442
        
 
443
        # Note: gnutls.connection.X509Credentials is really a generic
 
444
        # GnuTLS certificate credentials object so long as no X.509
 
445
        # keys are added to it.  Therefore, we can use it here despite
 
446
        # using OpenPGP certificates.
315
447
        
316
448
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
317
449
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
318
450
        #                "+DHE-DSS"))
319
 
        priority = "SECURE256"
320
 
        
 
451
        priority = "NORMAL"             # Fallback default, since this
 
452
                                        # MUST be set.
 
453
        if self.server.settings["priority"]:
 
454
            priority = self.server.settings["priority"]
321
455
        gnutls.library.functions.gnutls_priority_set_direct\
322
456
            (session._c_object, priority, None);
323
457
        
324
458
        try:
325
459
            session.handshake()
326
460
        except gnutls.errors.GNUTLSError, error:
327
 
            logger.debug(u"Handshake failed: %s", error)
 
461
            logger.warning(u"Handshake failed: %s", error)
328
462
            # Do not run session.bye() here: the session is not
329
463
            # established.  Just abandon the request.
330
464
            return
331
465
        try:
332
466
            fpr = fingerprint(peer_certificate(session))
333
467
        except (TypeError, gnutls.errors.GNUTLSError), error:
334
 
            logger.debug(u"Bad certificate: %s", error)
 
468
            logger.warning(u"Bad certificate: %s", error)
335
469
            session.bye()
336
470
            return
337
471
        logger.debug(u"Fingerprint: %s", fpr)
338
472
        client = None
339
 
        for c in clients:
 
473
        for c in self.server.clients:
340
474
            if c.fingerprint == fpr:
341
475
                client = c
342
476
                break
 
477
        if not client:
 
478
            logger.warning(u"Client not found for fingerprint: %s",
 
479
                           fpr)
 
480
            session.bye()
 
481
            return
343
482
        # Have to check if client.still_valid(), since it is possible
344
483
        # that the client timed out while establishing the GnuTLS
345
484
        # session.
346
 
        if (not client) or (not client.still_valid()):
347
 
            if client:
348
 
                logger.debug(u"Client %(name)s is invalid",
349
 
                             vars(client))
350
 
            else:
351
 
                logger.debug(u"Client not found for fingerprint: %s",
352
 
                             fpr)
 
485
        if not client.still_valid():
 
486
            logger.warning(u"Client %(name)s is invalid",
 
487
                           vars(client))
353
488
            session.bye()
354
489
            return
355
490
        sent_size = 0
365
500
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
366
501
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
367
502
    Attributes:
368
 
        options:        Command line options
 
503
        settings:       Server settings
369
504
        clients:        Set() of Client objects
370
505
    """
371
506
    address_family = socket.AF_INET6
372
507
    def __init__(self, *args, **kwargs):
373
 
        if "options" in kwargs:
374
 
            self.options = kwargs["options"]
375
 
            del kwargs["options"]
 
508
        if "settings" in kwargs:
 
509
            self.settings = kwargs["settings"]
 
510
            del kwargs["settings"]
376
511
        if "clients" in kwargs:
377
512
            self.clients = kwargs["clients"]
378
513
            del kwargs["clients"]
381
516
        """This overrides the normal server_bind() function
382
517
        to bind to an interface if one was specified, and also NOT to
383
518
        bind to an address or port if they were not specified."""
384
 
        if self.options.interface:
385
 
            if not hasattr(socket, "SO_BINDTODEVICE"):
386
 
                # From /usr/include/asm-i486/socket.h
387
 
                socket.SO_BINDTODEVICE = 25
 
519
        if self.settings["interface"]:
 
520
            # 25 is from /usr/include/asm-i486/socket.h
 
521
            SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)
388
522
            try:
389
523
                self.socket.setsockopt(socket.SOL_SOCKET,
390
 
                                       socket.SO_BINDTODEVICE,
391
 
                                       self.options.interface)
 
524
                                       SO_BINDTODEVICE,
 
525
                                       self.settings["interface"])
392
526
            except socket.error, error:
393
527
                if error[0] == errno.EPERM:
394
 
                    logger.warning(u"No permission to"
395
 
                                   u" bind to interface %s",
396
 
                                   self.options.interface)
 
528
                    logger.error(u"No permission to"
 
529
                                 u" bind to interface %s",
 
530
                                 self.settings["interface"])
397
531
                else:
398
532
                    raise error
399
533
        # Only bind(2) the socket if we really need to.
402
536
                in6addr_any = "::"
403
537
                self.server_address = (in6addr_any,
404
538
                                       self.server_address[1])
405
 
            elif self.server_address[1] is None:
 
539
            elif not self.server_address[1]:
406
540
                self.server_address = (self.server_address[0],
407
541
                                       0)
 
542
#                 if self.settings["interface"]:
 
543
#                     self.server_address = (self.server_address[0],
 
544
#                                            0, # port
 
545
#                                            0, # flowinfo
 
546
#                                            if_nametoindex
 
547
#                                            (self.settings
 
548
#                                             ["interface"]))
408
549
            return super(type(self), self).server_bind()
409
550
 
410
551
 
442
583
    return delta
443
584
 
444
585
 
445
 
def add_service():
446
 
    """From the Avahi server example code"""
447
 
    global group, serviceName, serviceType, servicePort, serviceTXT, \
448
 
           domain, host
449
 
    if group is None:
450
 
        group = dbus.Interface(
451
 
                bus.get_object( avahi.DBUS_NAME,
452
 
                                server.EntryGroupNew()),
453
 
                avahi.DBUS_INTERFACE_ENTRY_GROUP)
454
 
        group.connect_to_signal('StateChanged',
455
 
                                entry_group_state_changed)
456
 
    logger.debug(u"Adding service '%s' of type '%s' ...",
457
 
                 serviceName, serviceType)
458
 
    
459
 
    group.AddService(
460
 
            serviceInterface,           # interface
461
 
            avahi.PROTO_INET6,          # protocol
462
 
            dbus.UInt32(0),             # flags
463
 
            serviceName, serviceType,
464
 
            domain, host,
465
 
            dbus.UInt16(servicePort),
466
 
            avahi.string_array_to_txt_array(serviceTXT))
467
 
    group.Commit()
468
 
 
469
 
 
470
 
def remove_service():
471
 
    """From the Avahi server example code"""
472
 
    global group
473
 
    
474
 
    if not group is None:
475
 
        group.Reset()
476
 
 
477
 
 
478
586
def server_state_changed(state):
479
 
    """From the Avahi server example code"""
 
587
    """Derived from the Avahi example code"""
480
588
    if state == avahi.SERVER_COLLISION:
481
 
        logger.warning(u"Server name collision")
482
 
        remove_service()
 
589
        logger.error(u"Server name collision")
 
590
        service.remove()
483
591
    elif state == avahi.SERVER_RUNNING:
484
 
        add_service()
 
592
        service.add()
485
593
 
486
594
 
487
595
def entry_group_state_changed(state, error):
488
 
    """From the Avahi server example code"""
489
 
    global serviceName, server, rename_count
490
 
    
 
596
    """Derived from the Avahi example code"""
491
597
    logger.debug(u"state change: %i", state)
492
598
    
493
599
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
494
600
        logger.debug(u"Service established.")
495
601
    elif state == avahi.ENTRY_GROUP_COLLISION:
496
 
        
497
 
        rename_count = rename_count - 1
498
 
        if rename_count > 0:
499
 
            name = server.GetAlternativeServiceName(name)
500
 
            logger.warning(u"Service name collision, "
501
 
                           u"changing name to '%s' ...", name)
502
 
            remove_service()
503
 
            add_service()
504
 
            
505
 
        else:
506
 
            logger.error(u"No suitable service name found "
507
 
                         u"after %i retries, exiting.",
508
 
                         n_rename)
509
 
            main_loop.quit()
 
602
        logger.warning(u"Service name collision.")
 
603
        service.rename()
510
604
    elif state == avahi.ENTRY_GROUP_FAILURE:
511
 
        logger.error(u"Error in group state changed %s",
512
 
                     unicode(error))
513
 
        main_loop.quit()
514
 
        return
515
 
 
 
605
        logger.critical(u"Error in group state changed %s",
 
606
                        unicode(error))
 
607
        raise AvahiGroupError("State changed: %s", str(error))
516
608
 
517
609
def if_nametoindex(interface):
518
 
    """Call the C function if_nametoindex()"""
 
610
    """Call the C function if_nametoindex(), or equivalent"""
 
611
    global if_nametoindex
519
612
    try:
520
 
        libc = ctypes.cdll.LoadLibrary("libc.so.6")
521
 
        return libc.if_nametoindex(interface)
 
613
        if "ctypes.util" not in sys.modules:
 
614
            import ctypes.util
 
615
        if_nametoindex = ctypes.cdll.LoadLibrary\
 
616
            (ctypes.util.find_library("c")).if_nametoindex
522
617
    except (OSError, AttributeError):
523
618
        if "struct" not in sys.modules:
524
619
            import struct
525
620
        if "fcntl" not in sys.modules:
526
621
            import fcntl
527
 
        SIOCGIFINDEX = 0x8933      # From /usr/include/linux/sockios.h
528
 
        s = socket.socket()
529
 
        ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
530
 
                            struct.pack("16s16x", interface))
531
 
        s.close()
532
 
        interface_index = struct.unpack("I", ifreq[16:20])[0]
533
 
        return interface_index
534
 
 
535
 
 
536
 
if __name__ == '__main__':
537
 
    parser = OptionParser()
 
622
        def if_nametoindex(interface):
 
623
            "Get an interface index the hard way, i.e. using fcntl()"
 
624
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
 
625
            s = socket.socket()
 
626
            ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
 
627
                                struct.pack("16s16x", interface))
 
628
            s.close()
 
629
            interface_index = struct.unpack("I", ifreq[16:20])[0]
 
630
            return interface_index
 
631
    return if_nametoindex(interface)
 
632
 
 
633
 
 
634
def daemon(nochdir = False, noclose = False):
 
635
    """See daemon(3).  Standard BSD Unix function.
 
636
    This should really exist as os.daemon, but it doesn't (yet)."""
 
637
    if os.fork():
 
638
        sys.exit()
 
639
    os.setsid()
 
640
    if not nochdir:
 
641
        os.chdir("/")
 
642
    if os.fork():
 
643
        sys.exit()
 
644
    if not noclose:
 
645
        # Close all standard open file descriptors
 
646
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
 
647
        if not stat.S_ISCHR(os.fstat(null).st_mode):
 
648
            raise OSError(errno.ENODEV,
 
649
                          "/dev/null not a character device")
 
650
        os.dup2(null, sys.stdin.fileno())
 
651
        os.dup2(null, sys.stdout.fileno())
 
652
        os.dup2(null, sys.stderr.fileno())
 
653
        if null > 2:
 
654
            os.close(null)
 
655
 
 
656
 
 
657
def main():
 
658
    global main_loop_started
 
659
    main_loop_started = False
 
660
    
 
661
    parser = OptionParser(version = "%%prog %s" % version)
538
662
    parser.add_option("-i", "--interface", type="string",
539
 
                      default=None, metavar="IF",
540
 
                      help="Bind to interface IF")
541
 
    parser.add_option("--cert", type="string", default="cert.pem",
542
 
                      metavar="FILE",
543
 
                      help="Public key certificate PEM file to use")
544
 
    parser.add_option("--key", type="string", default="key.pem",
545
 
                      metavar="FILE",
546
 
                      help="Private key PEM file to use")
547
 
    parser.add_option("--ca", type="string", default="ca.pem",
548
 
                      metavar="FILE",
549
 
                      help="Certificate Authority certificate PEM file to use")
550
 
    parser.add_option("--crl", type="string", default="crl.pem",
551
 
                      metavar="FILE",
552
 
                      help="Certificate Revokation List PEM file to use")
553
 
    parser.add_option("-p", "--port", type="int", default=None,
 
663
                      metavar="IF", help="Bind to interface IF")
 
664
    parser.add_option("-a", "--address", type="string",
 
665
                      help="Address to listen for requests on")
 
666
    parser.add_option("-p", "--port", type="int",
554
667
                      help="Port number to receive requests on")
555
 
    parser.add_option("--timeout", type="string", # Parsed later
556
 
                      default="1h",
557
 
                      help="Amount of downtime allowed for clients")
558
 
    parser.add_option("--interval", type="string", # Parsed later
559
 
                      default="5m",
560
 
                      help="How often to check that a client is up")
561
668
    parser.add_option("--check", action="store_true", default=False,
562
669
                      help="Run self-test")
563
 
    parser.add_option("--debug", action="store_true", default=False,
564
 
                      help="Debug mode")
 
670
    parser.add_option("--debug", action="store_true",
 
671
                      help="Debug mode; run in foreground and log to"
 
672
                      " terminal")
 
673
    parser.add_option("--priority", type="string", help="GnuTLS"
 
674
                      " priority string (see GnuTLS documentation)")
 
675
    parser.add_option("--servicename", type="string", metavar="NAME",
 
676
                      help="Zeroconf service name")
 
677
    parser.add_option("--configdir", type="string",
 
678
                      default="/etc/mandos", metavar="DIR",
 
679
                      help="Directory to search for configuration"
 
680
                      " files")
565
681
    (options, args) = parser.parse_args()
566
682
    
567
683
    if options.check:
569
685
        doctest.testmod()
570
686
        sys.exit()
571
687
    
572
 
    # Parse the time arguments
573
 
    try:
574
 
        options.timeout = string_to_delta(options.timeout)
575
 
    except ValueError:
576
 
        parser.error("option --timeout: Unparseable time")
577
 
    try:
578
 
        options.interval = string_to_delta(options.interval)
579
 
    except ValueError:
580
 
        parser.error("option --interval: Unparseable time")
581
 
    
582
 
    # Parse config file
583
 
    defaults = { "checker": "sleep 1; fping -q -- %%(fqdn)s" }
584
 
    client_config = ConfigParser.SafeConfigParser(defaults)
585
 
    #client_config.readfp(open("secrets.conf"), "secrets.conf")
586
 
    client_config.read("mandos-clients.conf")
587
 
    
588
 
    # From the Avahi server example code
 
688
    # Default values for config file for server-global settings
 
689
    server_defaults = { "interface": "",
 
690
                        "address": "",
 
691
                        "port": "",
 
692
                        "debug": "False",
 
693
                        "priority":
 
694
                        "SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
 
695
                        "servicename": "Mandos",
 
696
                        }
 
697
    
 
698
    # Parse config file for server-global settings
 
699
    server_config = ConfigParser.SafeConfigParser(server_defaults)
 
700
    del server_defaults
 
701
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
 
702
    server_section = "server"
 
703
    # Convert the SafeConfigParser object to a dict
 
704
    server_settings = dict(server_config.items(server_section))
 
705
    # Use getboolean on the boolean config option
 
706
    server_settings["debug"] = server_config.getboolean\
 
707
                               (server_section, "debug")
 
708
    del server_config
 
709
    
 
710
    # Override the settings from the config file with command line
 
711
    # options, if set.
 
712
    for option in ("interface", "address", "port", "debug",
 
713
                   "priority", "servicename", "configdir"):
 
714
        value = getattr(options, option)
 
715
        if value is not None:
 
716
            server_settings[option] = value
 
717
    del options
 
718
    # Now we have our good server settings in "server_settings"
 
719
    
 
720
    debug = server_settings["debug"]
 
721
    
 
722
    if not debug:
 
723
        syslogger.setLevel(logging.WARNING)
 
724
        console.setLevel(logging.WARNING)
 
725
    
 
726
    if server_settings["servicename"] != "Mandos":
 
727
        syslogger.setFormatter(logging.Formatter\
 
728
                               ('Mandos (%s): %%(levelname)s:'
 
729
                                ' %%(message)s'
 
730
                                % server_settings["servicename"]))
 
731
    
 
732
    # Parse config file with clients
 
733
    client_defaults = { "timeout": "1h",
 
734
                        "interval": "5m",
 
735
                        "checker": "fping -q -- %%(host)s",
 
736
                        }
 
737
    client_config = ConfigParser.SafeConfigParser(client_defaults)
 
738
    client_config.read(os.path.join(server_settings["configdir"],
 
739
                                    "clients.conf"))
 
740
    
 
741
    global service
 
742
    service = AvahiService(name = server_settings["servicename"],
 
743
                           type = "_mandos._tcp", );
 
744
    if server_settings["interface"]:
 
745
        service.interface = if_nametoindex(server_settings["interface"])
 
746
    
 
747
    global main_loop
 
748
    global bus
 
749
    global server
 
750
    # From the Avahi example code
589
751
    DBusGMainLoop(set_as_default=True )
590
752
    main_loop = gobject.MainLoop()
591
753
    bus = dbus.SystemBus()
594
756
            avahi.DBUS_INTERFACE_SERVER )
595
757
    # End of Avahi example code
596
758
    
597
 
    debug = options.debug
598
 
    
599
759
    clients = Set()
600
760
    def remove_from_clients(client):
601
761
        clients.remove(client)
602
762
        if not clients:
603
 
            logger.debug(u"No clients left, exiting")
604
 
            main_loop.quit()
 
763
            logger.critical(u"No clients left, exiting")
 
764
            sys.exit()
605
765
    
606
 
    clients.update(Set(Client(name=section, options=options,
 
766
    clients.update(Set(Client(name = section,
607
767
                              stop_hook = remove_from_clients,
608
 
                              **(dict(client_config\
609
 
                                      .items(section))))
 
768
                              config
 
769
                              = dict(client_config.items(section)))
610
770
                       for section in client_config.sections()))
 
771
    if not clients:
 
772
        logger.critical(u"No clients defined")
 
773
        sys.exit(1)
 
774
    
 
775
    if not debug:
 
776
        logger.removeHandler(console)
 
777
        daemon()
 
778
    
 
779
    pidfilename = "/var/run/mandos/mandos.pid"
 
780
    pid = os.getpid()
 
781
    try:
 
782
        pidfile = open(pidfilename, "w")
 
783
        pidfile.write(str(pid) + "\n")
 
784
        pidfile.close()
 
785
        del pidfile
 
786
    except IOError, err:
 
787
        logger.error(u"Could not write %s file with PID %d",
 
788
                     pidfilename, os.getpid())
 
789
    
 
790
    def cleanup():
 
791
        "Cleanup function; run on exit"
 
792
        global group
 
793
        # From the Avahi example code
 
794
        if not group is None:
 
795
            group.Free()
 
796
            group = None
 
797
        # End of Avahi example code
 
798
        
 
799
        while clients:
 
800
            client = clients.pop()
 
801
            client.stop_hook = None
 
802
            client.stop()
 
803
    
 
804
    atexit.register(cleanup)
 
805
    
 
806
    if not debug:
 
807
        signal.signal(signal.SIGINT, signal.SIG_IGN)
 
808
    signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
 
809
    signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())
 
810
    
611
811
    for client in clients:
612
812
        client.start()
613
813
    
614
 
    tcp_server = IPv6_TCPServer((None, options.port),
 
814
    tcp_server = IPv6_TCPServer((server_settings["address"],
 
815
                                 server_settings["port"]),
615
816
                                tcp_handler,
616
 
                                options=options,
 
817
                                settings=server_settings,
617
818
                                clients=clients)
618
 
    # Find out what random port we got
619
 
    servicePort = tcp_server.socket.getsockname()[1]
620
 
    logger.debug(u"Now listening on port %d", servicePort)
621
 
    
622
 
    if options.interface is not None:
623
 
        serviceInterface = if_nametoindex(options.interface)
624
 
    
625
 
    # From the Avahi server example code
626
 
    server.connect_to_signal("StateChanged", server_state_changed)
627
 
    server_state_changed(server.GetState())
628
 
    # End of Avahi example code
629
 
    
630
 
    gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
631
 
                         lambda *args, **kwargs:
632
 
                         tcp_server.handle_request(*args[2:],
633
 
                                                   **kwargs) or True)
 
819
    # Find out what port we got
 
820
    service.port = tcp_server.socket.getsockname()[1]
 
821
    logger.info(u"Now listening on address %r, port %d, flowinfo %d,"
 
822
                u" scope_id %d" % tcp_server.socket.getsockname())
 
823
    
 
824
    #service.interface = tcp_server.socket.getsockname()[3]
 
825
    
634
826
    try:
 
827
        # From the Avahi example code
 
828
        server.connect_to_signal("StateChanged", server_state_changed)
 
829
        try:
 
830
            server_state_changed(server.GetState())
 
831
        except dbus.exceptions.DBusException, error:
 
832
            logger.critical(u"DBusException: %s", error)
 
833
            sys.exit(1)
 
834
        # End of Avahi example code
 
835
        
 
836
        gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
 
837
                             lambda *args, **kwargs:
 
838
                             tcp_server.handle_request\
 
839
                             (*args[2:], **kwargs) or True)
 
840
        
 
841
        logger.debug(u"Starting main loop")
 
842
        main_loop_started = True
635
843
        main_loop.run()
 
844
    except AvahiError, error:
 
845
        logger.critical(u"AvahiError: %s" + unicode(error))
 
846
        sys.exit(1)
636
847
    except KeyboardInterrupt:
637
 
        print
638
 
    
639
 
    # Cleanup here
 
848
        if debug:
 
849
            print
640
850
 
641
 
    # From the Avahi server example code
642
 
    if not group is None:
643
 
        group.Free()
644
 
    # End of Avahi example code
645
 
    
646
 
    for client in clients:
647
 
        client.stop_hook = None
648
 
        client.stop()
 
851
if __name__ == '__main__':
 
852
    main()