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  • Committer: Teddy Hogeborn
  • Date: 2008-01-30 17:28:18 UTC
  • Revision ID: teddy@fukt.bsnet.se-20080130172818-fnrq2xmtg1wa8wo2
* client.cpp (main): Get t_old early since it is used on error exits.

* server.py (Client.checker): New attribute.
  (Client.check_action, Client.start_checker, Client.stop_checker,
  Client.fileno, Client.next_stop, Client.still_valid,
  Client.it_is_time_to_check): New methods.
  (Client.handle_request): Alias to "check_action".
  (main): Stop all started checkers on exit.  Exit cleanly on keyboard
  interrupt.

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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
28
 
# <http://www.gnu.org/licenses/>.
29
 
30
 
# Contact the authors at <mandos@fukt.bsnet.se>.
31
 
32
 
 
33
 
from __future__ import division
34
2
 
35
3
import SocketServer
36
4
import socket
41
9
import gnutls.crypto
42
10
import gnutls.connection
43
11
import gnutls.errors
44
 
import gnutls.library.functions
45
 
import gnutls.library.constants
46
 
import gnutls.library.types
47
12
import ConfigParser
48
13
import sys
49
14
import re
50
15
import os
51
16
import signal
52
 
from sets import Set
53
 
import subprocess
54
 
import atexit
55
 
import stat
56
 
import logging
57
 
import logging.handlers
58
 
 
59
 
import dbus
60
 
import gobject
61
 
import avahi
62
 
from dbus.mainloop.glib import DBusGMainLoop
63
 
import ctypes
64
 
 
65
 
version = "1.0"
66
 
 
67
 
logger = logging.Logger('mandos')
68
 
syslogger = logging.handlers.SysLogHandler\
69
 
            (facility = logging.handlers.SysLogHandler.LOG_DAEMON,
70
 
             address = "/dev/log")
71
 
syslogger.setFormatter(logging.Formatter\
72
 
                        ('Mandos: %(levelname)s: %(message)s'))
73
 
logger.addHandler(syslogger)
74
 
 
75
 
console = logging.StreamHandler()
76
 
console.setFormatter(logging.Formatter('%(name)s: %(levelname)s:'
77
 
                                       ' %(message)s'))
78
 
logger.addHandler(console)
79
 
 
80
 
class AvahiError(Exception):
81
 
    def __init__(self, value):
82
 
        self.value = value
83
 
    def __str__(self):
84
 
        return repr(self.value)
85
 
 
86
 
class AvahiServiceError(AvahiError):
87
 
    pass
88
 
 
89
 
class AvahiGroupError(AvahiError):
90
 
    pass
91
 
 
92
 
 
93
 
class AvahiService(object):
94
 
    """An Avahi (Zeroconf) service.
95
 
    Attributes:
96
 
    interface: integer; avahi.IF_UNSPEC or an interface index.
97
 
               Used to optionally bind to the specified interface.
98
 
    name: string; Example: 'Mandos'
99
 
    type: string; Example: '_mandos._tcp'.
100
 
                  See <http://www.dns-sd.org/ServiceTypes.html>
101
 
    port: integer; what port to announce
102
 
    TXT: list of strings; TXT record for the service
103
 
    domain: string; Domain to publish on, default to .local if empty.
104
 
    host: string; Host to publish records for, default is localhost
105
 
    max_renames: integer; maximum number of renames
106
 
    rename_count: integer; counter so we only rename after collisions
107
 
                  a sensible number of times
108
 
    """
109
 
    def __init__(self, interface = avahi.IF_UNSPEC, name = None,
110
 
                 type = None, port = None, TXT = None, domain = "",
111
 
                 host = "", max_renames = 32768):
112
 
        self.interface = interface
113
 
        self.name = name
114
 
        self.type = type
115
 
        self.port = port
116
 
        if TXT is None:
117
 
            self.TXT = []
118
 
        else:
119
 
            self.TXT = TXT
120
 
        self.domain = domain
121
 
        self.host = host
122
 
        self.rename_count = 0
123
 
        self.max_renames = max_renames
124
 
    def rename(self):
125
 
        """Derived from the Avahi example code"""
126
 
        if self.rename_count >= self.max_renames:
127
 
            logger.critical(u"No suitable Zeroconf service name found"
128
 
                            u" after %i retries, exiting.",
129
 
                            rename_count)
130
 
            raise AvahiServiceError("Too many renames")
131
 
        self.name = server.GetAlternativeServiceName(self.name)
132
 
        logger.info(u"Changing Zeroconf service name to %r ...",
133
 
                    str(self.name))
134
 
        syslogger.setFormatter(logging.Formatter\
135
 
                               ('Mandos (%s): %%(levelname)s:'
136
 
                               ' %%(message)s' % self.name))
137
 
        self.remove()
138
 
        self.add()
139
 
        self.rename_count += 1
140
 
    def remove(self):
141
 
        """Derived from the Avahi example code"""
142
 
        if group is not None:
143
 
            group.Reset()
144
 
    def add(self):
145
 
        """Derived from the Avahi example code"""
146
 
        global group
147
 
        if group is None:
148
 
            group = dbus.Interface\
149
 
                    (bus.get_object(avahi.DBUS_NAME,
150
 
                                    server.EntryGroupNew()),
151
 
                     avahi.DBUS_INTERFACE_ENTRY_GROUP)
152
 
            group.connect_to_signal('StateChanged',
153
 
                                    entry_group_state_changed)
154
 
        logger.debug(u"Adding Zeroconf service '%s' of type '%s' ...",
155
 
                     service.name, service.type)
156
 
        group.AddService(
157
 
                self.interface,         # interface
158
 
                avahi.PROTO_INET6,      # protocol
159
 
                dbus.UInt32(0),         # flags
160
 
                self.name, self.type,
161
 
                self.domain, self.host,
162
 
                dbus.UInt16(self.port),
163
 
                avahi.string_array_to_txt_array(self.TXT))
164
 
        group.Commit()
165
 
 
166
 
# From the Avahi example code:
167
 
group = None                            # our entry group
168
 
# End of Avahi example code
169
 
 
170
17
 
171
18
class Client(object):
172
 
    """A representation of a client host served by this server.
173
 
    Attributes:
174
 
    name:      string; from the config file, used in log messages
175
 
    fingerprint: string (40 or 32 hexadecimal digits); used to
176
 
                 uniquely identify the client
177
 
    secret:    bytestring; sent verbatim (over TLS) to client
178
 
    host:      string; available for use by the checker command
179
 
    created:   datetime.datetime(); object creation, not client host
180
 
    last_checked_ok: datetime.datetime() or None if not yet checked OK
181
 
    timeout:   datetime.timedelta(); How long from last_checked_ok
182
 
                                     until this client is invalid
183
 
    interval:  datetime.timedelta(); How often to start a new checker
184
 
    stop_hook: If set, called by stop() as stop_hook(self)
185
 
    checker:   subprocess.Popen(); a running checker process used
186
 
                                   to see if the client lives.
187
 
                                   'None' if no process is running.
188
 
    checker_initiator_tag: a gobject event source tag, or None
189
 
    stop_initiator_tag:    - '' -
190
 
    checker_callback_tag:  - '' -
191
 
    checker_command: string; External command which is run to check if
192
 
                     client lives.  %() expansions are done at
193
 
                     runtime with vars(self) as dict, so that for
194
 
                     instance %(name)s can be used in the command.
195
 
    Private attibutes:
196
 
    _timeout: Real variable for 'timeout'
197
 
    _interval: Real variable for 'interval'
198
 
    _timeout_milliseconds: Used when calling gobject.timeout_add()
199
 
    _interval_milliseconds: - '' -
200
 
    """
201
 
    def _set_timeout(self, timeout):
202
 
        "Setter function for 'timeout' attribute"
203
 
        self._timeout = timeout
204
 
        self._timeout_milliseconds = ((self.timeout.days
205
 
                                       * 24 * 60 * 60 * 1000)
206
 
                                      + (self.timeout.seconds * 1000)
207
 
                                      + (self.timeout.microseconds
208
 
                                         // 1000))
209
 
    timeout = property(lambda self: self._timeout,
210
 
                       _set_timeout)
211
 
    del _set_timeout
212
 
    def _set_interval(self, interval):
213
 
        "Setter function for 'interval' attribute"
214
 
        self._interval = interval
215
 
        self._interval_milliseconds = ((self.interval.days
216
 
                                        * 24 * 60 * 60 * 1000)
217
 
                                       + (self.interval.seconds
218
 
                                          * 1000)
219
 
                                       + (self.interval.microseconds
220
 
                                          // 1000))
221
 
    interval = property(lambda self: self._interval,
222
 
                        _set_interval)
223
 
    del _set_interval
224
 
    def __init__(self, name = None, stop_hook=None, config={}):
225
 
        """Note: the 'checker' key in 'config' sets the
226
 
        'checker_command' attribute and *not* the 'checker'
227
 
        attribute."""
 
19
    def __init__(self, name=None, options=None, dn=None,
 
20
                 password=None, passfile=None, fqdn=None,
 
21
                 timeout=None, interval=-1):
228
22
        self.name = name
229
 
        logger.debug(u"Creating client %r", self.name)
230
 
        # Uppercase and remove spaces from fingerprint for later
231
 
        # comparison purposes with return value from the fingerprint()
232
 
        # function
233
 
        self.fingerprint = config["fingerprint"].upper()\
234
 
                           .replace(u" ", u"")
235
 
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
236
 
        if "secret" in config:
237
 
            self.secret = config["secret"].decode(u"base64")
238
 
        elif "secfile" in config:
239
 
            sf = open(config["secfile"])
240
 
            self.secret = sf.read()
241
 
            sf.close()
 
23
        self.dn = dn
 
24
        if password:
 
25
            self.password = password
 
26
        elif passfile:
 
27
            self.password = open(passfile).readall()
242
28
        else:
243
 
            raise TypeError(u"No secret or secfile for client %s"
244
 
                            % self.name)
245
 
        self.host = config.get("host", "")
 
29
            print "No Password or Passfile in client config file"
 
30
            # raise RuntimeError XXX
 
31
            self.password = "gazonk"
 
32
        self.fqdn = fqdn                # string
246
33
        self.created = datetime.datetime.now()
247
 
        self.last_checked_ok = None
248
 
        self.timeout = string_to_delta(config["timeout"])
249
 
        self.interval = string_to_delta(config["interval"])
250
 
        self.stop_hook = stop_hook
251
 
        self.checker = None
252
 
        self.checker_initiator_tag = None
253
 
        self.stop_initiator_tag = None
254
 
        self.checker_callback_tag = None
255
 
        self.check_command = config["checker"]
256
 
    def start(self):
257
 
        """Start this client's checker and timeout hooks"""
258
 
        # Schedule a new checker to be started an 'interval' from now,
259
 
        # and every interval from then on.
260
 
        self.checker_initiator_tag = gobject.timeout_add\
261
 
                                     (self._interval_milliseconds,
262
 
                                      self.start_checker)
263
 
        # Also start a new checker *right now*.
264
 
        self.start_checker()
265
 
        # Schedule a stop() when 'timeout' has passed
266
 
        self.stop_initiator_tag = gobject.timeout_add\
267
 
                                  (self._timeout_milliseconds,
268
 
                                   self.stop)
269
 
    def stop(self):
270
 
        """Stop this client.
271
 
        The possibility that a client might be restarted is left open,
272
 
        but not currently used."""
273
 
        # If this client doesn't have a secret, it is already stopped.
274
 
        if hasattr(self, "secret") and self.secret:
275
 
            logger.info(u"Stopping client %s", self.name)
276
 
            self.secret = None
277
 
        else:
278
 
            return False
279
 
        if getattr(self, "stop_initiator_tag", False):
280
 
            gobject.source_remove(self.stop_initiator_tag)
281
 
            self.stop_initiator_tag = None
282
 
        if getattr(self, "checker_initiator_tag", False):
283
 
            gobject.source_remove(self.checker_initiator_tag)
284
 
            self.checker_initiator_tag = None
 
34
        self.last_seen = None           # datetime.datetime()
 
35
        if timeout is None:
 
36
            timeout = options.timeout
 
37
        self.timeout = timeout          # datetime.timedelta()
 
38
        if interval == -1:
 
39
            interval = options.interval
 
40
        self.interval = interval        # datetime.timedelta()
 
41
        self.next_check = datetime.datetime.now() # datetime.datetime()
 
42
        self.checker = None             # or a subprocess.Popen()
 
43
    def check_action(self, now=None):
 
44
        """The checker said something and might have completed.
 
45
        Check if is has, and take appropriate actions."""
 
46
        if self.checker.poll() is None:
 
47
            # False alarm, no result yet
 
48
            #self.checker.read()
 
49
            return
 
50
        if now is None:
 
51
            now = datetime.datetime.now()
 
52
        if self.checker.returncode == 0:
 
53
            self.last_seen = now
 
54
        while self.next_check <= now:
 
55
            self.next_check += self.interval
 
56
    handle_request = check_action
 
57
    def start_checker(self):
285
58
        self.stop_checker()
286
 
        if self.stop_hook:
287
 
            self.stop_hook(self)
288
 
        # Do not run this again if called by a gobject.timeout_add
289
 
        return False
290
 
    def __del__(self):
291
 
        self.stop_hook = None
292
 
        self.stop()
293
 
    def checker_callback(self, pid, condition):
294
 
        """The checker has completed, so take appropriate actions."""
295
 
        now = datetime.datetime.now()
296
 
        self.checker_callback_tag = None
 
59
        try:
 
60
            self.checker = subprocess.Popen("sleep 1; fping -q -- %s"
 
61
                                            % re.escape(self.fqdn),
 
62
                                            stdout=subprocess.PIPE,
 
63
                                            close_fds=True,
 
64
                                            shell=True, cwd="/")
 
65
        except subprocess.OSError, e:
 
66
            print "Failed to start subprocess:", e
 
67
    def stop_checker(self):
 
68
        if self.checker is None:
 
69
            return
 
70
        os.kill(self.checker.pid, signal.SIGTERM)
 
71
        if self.checker.poll() is None:
 
72
            os.kill(self.checker.pid, signal.SIGKILL)
297
73
        self.checker = None
298
 
        if os.WIFEXITED(condition) \
299
 
               and (os.WEXITSTATUS(condition) == 0):
300
 
            logger.info(u"Checker for %(name)s succeeded",
301
 
                        vars(self))
302
 
            self.last_checked_ok = now
303
 
            gobject.source_remove(self.stop_initiator_tag)
304
 
            self.stop_initiator_tag = gobject.timeout_add\
305
 
                                      (self._timeout_milliseconds,
306
 
                                       self.stop)
307
 
        elif not os.WIFEXITED(condition):
308
 
            logger.warning(u"Checker for %(name)s crashed?",
309
 
                           vars(self))
310
 
        else:
311
 
            logger.info(u"Checker for %(name)s failed",
312
 
                        vars(self))
313
 
    def start_checker(self):
314
 
        """Start a new checker subprocess if one is not running.
315
 
        If a checker already exists, leave it running and do
316
 
        nothing."""
317
 
        # The reason for not killing a running checker is that if we
318
 
        # did that, then if a checker (for some reason) started
319
 
        # running slowly and taking more than 'interval' time, the
320
 
        # client would inevitably timeout, since no checker would get
321
 
        # a chance to run to completion.  If we instead leave running
322
 
        # checkers alone, the checker would have to take more time
323
 
        # than 'timeout' for the client to be declared invalid, which
324
 
        # is as it should be.
 
74
    __del__ = stop_checker
 
75
    def fileno(self):
325
76
        if self.checker is None:
326
 
            try:
327
 
                # In case check_command has exactly one % operator
328
 
                command = self.check_command % self.host
329
 
            except TypeError:
330
 
                # Escape attributes for the shell
331
 
                escaped_attrs = dict((key, re.escape(str(val)))
332
 
                                     for key, val in
333
 
                                     vars(self).iteritems())
 
77
            return None
 
78
        return self.checker.stdout.fileno()
 
79
    def next_stop(self):
 
80
        """The time when something must be done about this client"""
 
81
        return min(self.last_seen + self.timeout, self.next_check)
 
82
    def still_valid(self, now=None):
 
83
        """Has this client's timeout not passed?"""
 
84
        if now is None:
 
85
            now = datetime.datetime.now()
 
86
        return now < (self.last_seen + timeout)
 
87
    def it_is_time_to_check(self, now=None):
 
88
        if now is None:
 
89
            now = datetime.datetime.now()
 
90
        return self.next_check <= now
 
91
 
 
92
 
 
93
class server_metaclass(type):
 
94
    "Common behavior for the UDP and TCP server classes"
 
95
    def __new__(cls, name, bases, attrs):
 
96
        attrs["address_family"] = socket.AF_INET6
 
97
        attrs["allow_reuse_address"] = True
 
98
        def server_bind(self):
 
99
            if self.options.interface:
 
100
                if not hasattr(socket, "SO_BINDTODEVICE"):
 
101
                    # From /usr/include/asm-i486/socket.h
 
102
                    socket.SO_BINDTODEVICE = 25
334
103
                try:
335
 
                    command = self.check_command % escaped_attrs
336
 
                except TypeError, error:
337
 
                    logger.error(u'Could not format string "%s":'
338
 
                                 u' %s', self.check_command, error)
339
 
                    return True # Try again later
340
 
            try:
341
 
                logger.info(u"Starting checker %r for %s",
342
 
                            command, self.name)
343
 
                # We don't need to redirect stdout and stderr, since
344
 
                # in normal mode, that is already done by daemon(),
345
 
                # and in debug mode we don't want to.  (Stdin is
346
 
                # always replaced by /dev/null.)
347
 
                self.checker = subprocess.Popen(command,
348
 
                                                close_fds=True,
349
 
                                                shell=True, cwd="/")
350
 
                self.checker_callback_tag = gobject.child_watch_add\
351
 
                                            (self.checker.pid,
352
 
                                             self.checker_callback)
353
 
            except OSError, error:
354
 
                logger.error(u"Failed to start subprocess: %s",
355
 
                             error)
356
 
        # Re-run this periodically if run by gobject.timeout_add
357
 
        return True
358
 
    def stop_checker(self):
359
 
        """Force the checker process, if any, to stop."""
360
 
        if self.checker_callback_tag:
361
 
            gobject.source_remove(self.checker_callback_tag)
362
 
            self.checker_callback_tag = None
363
 
        if getattr(self, "checker", None) is None:
364
 
            return
365
 
        logger.debug(u"Stopping checker for %(name)s", vars(self))
366
 
        try:
367
 
            os.kill(self.checker.pid, signal.SIGTERM)
368
 
            #os.sleep(0.5)
369
 
            #if self.checker.poll() is None:
370
 
            #    os.kill(self.checker.pid, signal.SIGKILL)
371
 
        except OSError, error:
372
 
            if error.errno != errno.ESRCH: # No such process
373
 
                raise
374
 
        self.checker = None
375
 
    def still_valid(self):
376
 
        """Has the timeout not yet passed for this client?"""
377
 
        now = datetime.datetime.now()
378
 
        if self.last_checked_ok is None:
379
 
            return now < (self.created + self.timeout)
380
 
        else:
381
 
            return now < (self.last_checked_ok + self.timeout)
382
 
 
383
 
 
384
 
def peer_certificate(session):
385
 
    "Return the peer's OpenPGP certificate as a bytestring"
386
 
    # If not an OpenPGP certificate...
387
 
    if gnutls.library.functions.gnutls_certificate_type_get\
388
 
            (session._c_object) \
389
 
           != gnutls.library.constants.GNUTLS_CRT_OPENPGP:
390
 
        # ...do the normal thing
391
 
        return session.peer_certificate
392
 
    list_size = ctypes.c_uint()
393
 
    cert_list = gnutls.library.functions.gnutls_certificate_get_peers\
394
 
        (session._c_object, ctypes.byref(list_size))
395
 
    if list_size.value == 0:
396
 
        return None
397
 
    cert = cert_list[0]
398
 
    return ctypes.string_at(cert.data, cert.size)
399
 
 
400
 
 
401
 
def fingerprint(openpgp):
402
 
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
403
 
    # New GnuTLS "datum" with the OpenPGP public key
404
 
    datum = gnutls.library.types.gnutls_datum_t\
405
 
        (ctypes.cast(ctypes.c_char_p(openpgp),
406
 
                     ctypes.POINTER(ctypes.c_ubyte)),
407
 
         ctypes.c_uint(len(openpgp)))
408
 
    # New empty GnuTLS certificate
409
 
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
410
 
    gnutls.library.functions.gnutls_openpgp_crt_init\
411
 
        (ctypes.byref(crt))
412
 
    # Import the OpenPGP public key into the certificate
413
 
    gnutls.library.functions.gnutls_openpgp_crt_import\
414
 
                    (crt, ctypes.byref(datum),
415
 
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
416
 
    # Verify the self signature in the key
417
 
    crtverify = ctypes.c_uint();
418
 
    gnutls.library.functions.gnutls_openpgp_crt_verify_self\
419
 
        (crt, 0, ctypes.byref(crtverify))
420
 
    if crtverify.value != 0:
421
 
        gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
422
 
        raise gnutls.errors.CertificateSecurityError("Verify failed")
423
 
    # New buffer for the fingerprint
424
 
    buffer = ctypes.create_string_buffer(20)
425
 
    buffer_length = ctypes.c_size_t()
426
 
    # Get the fingerprint from the certificate into the buffer
427
 
    gnutls.library.functions.gnutls_openpgp_crt_get_fingerprint\
428
 
        (crt, ctypes.byref(buffer), ctypes.byref(buffer_length))
429
 
    # Deinit the certificate
430
 
    gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
431
 
    # Convert the buffer to a Python bytestring
432
 
    fpr = ctypes.string_at(buffer, buffer_length.value)
433
 
    # Convert the bytestring to hexadecimal notation
434
 
    hex_fpr = u''.join(u"%02X" % ord(char) for char in fpr)
435
 
    return hex_fpr
 
104
                    self.socket.setsockopt(socket.SOL_SOCKET,
 
105
                                           socket.SO_BINDTODEVICE,
 
106
                                           self.options.interface)
 
107
                except socket.error, error:
 
108
                    if error[0] == errno.EPERM:
 
109
                        print "Warning: No permission to bind to interface", \
 
110
                              self.options.interface
 
111
                    else:
 
112
                        raise error
 
113
            return super(type(self), self).server_bind()
 
114
        attrs["server_bind"] = server_bind
 
115
        def init(self, *args, **kwargs):
 
116
            if "options" in kwargs:
 
117
                self.options = kwargs["options"]
 
118
                del kwargs["options"]
 
119
            if "clients" in kwargs:
 
120
                self.clients = kwargs["clients"]
 
121
                del kwargs["clients"]
 
122
            if "credentials" in kwargs:
 
123
                self.credentials = kwargs["credentials"]
 
124
                del kwargs["credentials"]
 
125
            return super(type(self), self).__init__(*args, **kwargs)
 
126
        attrs["__init__"] = init
 
127
        return type.__new__(cls, name, bases, attrs)
 
128
 
 
129
 
 
130
class udp_handler(SocketServer.DatagramRequestHandler, object):
 
131
    def handle(self):
 
132
        self.wfile.write("Polo")
 
133
        print "UDP request answered"
 
134
 
 
135
 
 
136
class IPv6_UDPServer(SocketServer.UDPServer, object):
 
137
    __metaclass__ = server_metaclass
 
138
    def verify_request(self, request, client_address):
 
139
        print "UDP request came"
 
140
        return request[0] == "Marco"
436
141
 
437
142
 
438
143
class tcp_handler(SocketServer.BaseRequestHandler, object):
439
 
    """A TCP request handler class.
440
 
    Instantiated by IPv6_TCPServer for each request to handle it.
441
 
    Note: This will run in its own forked process."""
442
 
    
443
144
    def handle(self):
444
 
        logger.info(u"TCP connection from: %s",
445
 
                     unicode(self.client_address))
446
 
        session = gnutls.connection.ClientSession\
447
 
                  (self.request, gnutls.connection.X509Credentials())
448
 
        
449
 
        line = self.request.makefile().readline()
450
 
        logger.debug(u"Protocol version: %r", line)
451
 
        try:
452
 
            if int(line.strip().split()[0]) > 1:
453
 
                raise RuntimeError
454
 
        except (ValueError, IndexError, RuntimeError), error:
455
 
            logger.error(u"Unknown protocol version: %s", error)
456
 
            return
457
 
        
458
 
        # Note: gnutls.connection.X509Credentials is really a generic
459
 
        # GnuTLS certificate credentials object so long as no X.509
460
 
        # keys are added to it.  Therefore, we can use it here despite
461
 
        # using OpenPGP certificates.
462
 
        
463
 
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
464
 
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
465
 
        #                "+DHE-DSS"))
466
 
        priority = "NORMAL"             # Fallback default, since this
467
 
                                        # MUST be set.
468
 
        if self.server.settings["priority"]:
469
 
            priority = self.server.settings["priority"]
470
 
        gnutls.library.functions.gnutls_priority_set_direct\
471
 
            (session._c_object, priority, None);
472
 
        
473
 
        try:
474
 
            session.handshake()
475
 
        except gnutls.errors.GNUTLSError, error:
476
 
            logger.warning(u"Handshake failed: %s", error)
477
 
            # Do not run session.bye() here: the session is not
478
 
            # established.  Just abandon the request.
479
 
            return
480
 
        try:
481
 
            fpr = fingerprint(peer_certificate(session))
482
 
        except (TypeError, gnutls.errors.GNUTLSError), error:
483
 
            logger.warning(u"Bad certificate: %s", error)
484
 
            session.bye()
485
 
            return
486
 
        logger.debug(u"Fingerprint: %s", fpr)
487
 
        client = None
488
 
        for c in self.server.clients:
489
 
            if c.fingerprint == fpr:
490
 
                client = c
491
 
                break
492
 
        if not client:
493
 
            logger.warning(u"Client not found for fingerprint: %s",
494
 
                           fpr)
495
 
            session.bye()
496
 
            return
497
 
        # Have to check if client.still_valid(), since it is possible
498
 
        # that the client timed out while establishing the GnuTLS
499
 
        # session.
500
 
        if not client.still_valid():
501
 
            logger.warning(u"Client %(name)s is invalid",
502
 
                           vars(client))
503
 
            session.bye()
504
 
            return
505
 
        sent_size = 0
506
 
        while sent_size < len(client.secret):
507
 
            sent = session.send(client.secret[sent_size:])
508
 
            logger.debug(u"Sent: %d, remaining: %d",
509
 
                         sent, len(client.secret)
510
 
                         - (sent_size + sent))
511
 
            sent_size += sent
 
145
        print "TCP request came"
 
146
        print "Request:", self.request
 
147
        print "Client Address:", self.client_address
 
148
        print "Server:", self.server
 
149
        session = gnutls.connection.ServerSession(self.request,
 
150
                                                  self.server.credentials)
 
151
        session.handshake()
 
152
        if session.peer_certificate:
 
153
            print "DN:", session.peer_certificate.subject
 
154
        try:
 
155
            session.verify_peer()
 
156
        except gnutls.errors.CertificateError, error:
 
157
            print "Verify failed", error
 
158
            session.bye()
 
159
            return
 
160
        try:
 
161
            session.send(dict((client.dn, client.password)
 
162
                              for client in self.server.clients)
 
163
                         [session.peer_certificate.subject])
 
164
        except KeyError:
 
165
            session.send("gazonk")
 
166
            # Log maybe? XXX
512
167
        session.bye()
513
168
 
514
169
 
515
170
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
516
 
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
517
 
    Attributes:
518
 
        settings:       Server settings
519
 
        clients:        Set() of Client objects
520
 
    """
521
 
    address_family = socket.AF_INET6
522
 
    def __init__(self, *args, **kwargs):
523
 
        if "settings" in kwargs:
524
 
            self.settings = kwargs["settings"]
525
 
            del kwargs["settings"]
526
 
        if "clients" in kwargs:
527
 
            self.clients = kwargs["clients"]
528
 
            del kwargs["clients"]
529
 
        return super(type(self), self).__init__(*args, **kwargs)
530
 
    def server_bind(self):
531
 
        """This overrides the normal server_bind() function
532
 
        to bind to an interface if one was specified, and also NOT to
533
 
        bind to an address or port if they were not specified."""
534
 
        if self.settings["interface"]:
535
 
            # 25 is from /usr/include/asm-i486/socket.h
536
 
            SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)
537
 
            try:
538
 
                self.socket.setsockopt(socket.SOL_SOCKET,
539
 
                                       SO_BINDTODEVICE,
540
 
                                       self.settings["interface"])
541
 
            except socket.error, error:
542
 
                if error[0] == errno.EPERM:
543
 
                    logger.error(u"No permission to"
544
 
                                 u" bind to interface %s",
545
 
                                 self.settings["interface"])
546
 
                else:
547
 
                    raise error
548
 
        # Only bind(2) the socket if we really need to.
549
 
        if self.server_address[0] or self.server_address[1]:
550
 
            if not self.server_address[0]:
551
 
                in6addr_any = "::"
552
 
                self.server_address = (in6addr_any,
553
 
                                       self.server_address[1])
554
 
            elif not self.server_address[1]:
555
 
                self.server_address = (self.server_address[0],
556
 
                                       0)
557
 
#                 if self.settings["interface"]:
558
 
#                     self.server_address = (self.server_address[0],
559
 
#                                            0, # port
560
 
#                                            0, # flowinfo
561
 
#                                            if_nametoindex
562
 
#                                            (self.settings
563
 
#                                             ["interface"]))
564
 
            return super(type(self), self).server_bind()
565
 
 
 
171
    __metaclass__ = server_metaclass
 
172
    request_queue_size = 1024
 
173
 
 
174
 
 
175
in6addr_any = "::"
566
176
 
567
177
def string_to_delta(interval):
568
178
    """Parse a string and return a datetime.timedelta
577
187
    datetime.timedelta(1)
578
188
    >>> string_to_delta(u'1w')
579
189
    datetime.timedelta(7)
580
 
    >>> string_to_delta('5m 30s')
581
 
    datetime.timedelta(0, 330)
582
190
    """
583
 
    timevalue = datetime.timedelta(0)
584
 
    for s in interval.split():
585
 
        try:
586
 
            suffix=unicode(s[-1])
587
 
            value=int(s[:-1])
588
 
            if suffix == u"d":
589
 
                delta = datetime.timedelta(value)
590
 
            elif suffix == u"s":
591
 
                delta = datetime.timedelta(0, value)
592
 
            elif suffix == u"m":
593
 
                delta = datetime.timedelta(0, 0, 0, 0, value)
594
 
            elif suffix == u"h":
595
 
                delta = datetime.timedelta(0, 0, 0, 0, 0, value)
596
 
            elif suffix == u"w":
597
 
                delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
598
 
            else:
599
 
                raise ValueError
600
 
        except (ValueError, IndexError):
 
191
    try:
 
192
        suffix=unicode(interval[-1])
 
193
        value=int(interval[:-1])
 
194
        if suffix == u"d":
 
195
            delta = datetime.timedelta(value)
 
196
        elif suffix == u"s":
 
197
            delta = datetime.timedelta(0, value)
 
198
        elif suffix == u"m":
 
199
            delta = datetime.timedelta(0, 0, 0, 0, value)
 
200
        elif suffix == u"h":
 
201
            delta = datetime.timedelta(0, 0, 0, 0, 0, value)
 
202
        elif suffix == u"w":
 
203
            delta = datetime.timedelta(0, 0, 0, 0, 0, 0, value)
 
204
        else:
601
205
            raise ValueError
602
 
        timevalue += delta
603
 
    return timevalue
604
 
 
605
 
 
606
 
def server_state_changed(state):
607
 
    """Derived from the Avahi example code"""
608
 
    if state == avahi.SERVER_COLLISION:
609
 
        logger.error(u"Zeroconf server name collision")
610
 
        service.remove()
611
 
    elif state == avahi.SERVER_RUNNING:
612
 
        service.add()
613
 
 
614
 
 
615
 
def entry_group_state_changed(state, error):
616
 
    """Derived from the Avahi example code"""
617
 
    logger.debug(u"Avahi state change: %i", state)
618
 
    
619
 
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
620
 
        logger.debug(u"Zeroconf service established.")
621
 
    elif state == avahi.ENTRY_GROUP_COLLISION:
622
 
        logger.warning(u"Zeroconf service name collision.")
623
 
        service.rename()
624
 
    elif state == avahi.ENTRY_GROUP_FAILURE:
625
 
        logger.critical(u"Avahi: Error in group state changed %s",
626
 
                        unicode(error))
627
 
        raise AvahiGroupError("State changed: %s", str(error))
628
 
 
629
 
def if_nametoindex(interface):
630
 
    """Call the C function if_nametoindex(), or equivalent"""
631
 
    global if_nametoindex
632
 
    try:
633
 
        if "ctypes.util" not in sys.modules:
634
 
            import ctypes.util
635
 
        if_nametoindex = ctypes.cdll.LoadLibrary\
636
 
            (ctypes.util.find_library("c")).if_nametoindex
637
 
    except (OSError, AttributeError):
638
 
        if "struct" not in sys.modules:
639
 
            import struct
640
 
        if "fcntl" not in sys.modules:
641
 
            import fcntl
642
 
        def if_nametoindex(interface):
643
 
            "Get an interface index the hard way, i.e. using fcntl()"
644
 
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
645
 
            s = socket.socket()
646
 
            ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
647
 
                                struct.pack("16s16x", interface))
648
 
            s.close()
649
 
            interface_index = struct.unpack("I", ifreq[16:20])[0]
650
 
            return interface_index
651
 
    return if_nametoindex(interface)
652
 
 
653
 
 
654
 
def daemon(nochdir = False, noclose = False):
655
 
    """See daemon(3).  Standard BSD Unix function.
656
 
    This should really exist as os.daemon, but it doesn't (yet)."""
657
 
    if os.fork():
658
 
        sys.exit()
659
 
    os.setsid()
660
 
    if not nochdir:
661
 
        os.chdir("/")
662
 
    if os.fork():
663
 
        sys.exit()
664
 
    if not noclose:
665
 
        # Close all standard open file descriptors
666
 
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
667
 
        if not stat.S_ISCHR(os.fstat(null).st_mode):
668
 
            raise OSError(errno.ENODEV,
669
 
                          "/dev/null not a character device")
670
 
        os.dup2(null, sys.stdin.fileno())
671
 
        os.dup2(null, sys.stdout.fileno())
672
 
        os.dup2(null, sys.stderr.fileno())
673
 
        if null > 2:
674
 
            os.close(null)
 
206
    except (ValueError, IndexError):
 
207
        raise ValueError
 
208
    return delta
675
209
 
676
210
 
677
211
def main():
678
 
    global main_loop_started
679
 
    main_loop_started = False
680
 
    
681
 
    parser = OptionParser(version = "%%prog %s" % version)
 
212
    parser = OptionParser()
682
213
    parser.add_option("-i", "--interface", type="string",
683
 
                      metavar="IF", help="Bind to interface IF")
684
 
    parser.add_option("-a", "--address", type="string",
685
 
                      help="Address to listen for requests on")
686
 
    parser.add_option("-p", "--port", type="int",
 
214
                      default="eth0", metavar="IF",
 
215
                      help="Interface to bind to")
 
216
    parser.add_option("--cert", type="string", default="cert.pem",
 
217
                      metavar="FILE",
 
218
                      help="Public key certificate to use")
 
219
    parser.add_option("--key", type="string", default="key.pem",
 
220
                      metavar="FILE",
 
221
                      help="Private key to use")
 
222
    parser.add_option("--ca", type="string", default="ca.pem",
 
223
                      metavar="FILE",
 
224
                      help="Certificate Authority certificate to use")
 
225
    parser.add_option("--crl", type="string", default="crl.pem",
 
226
                      metavar="FILE",
 
227
                      help="Certificate Revokation List to use")
 
228
    parser.add_option("-p", "--port", type="int", default=49001,
687
229
                      help="Port number to receive requests on")
 
230
    parser.add_option("--dh", type="int", metavar="BITS",
 
231
                      help="DH group to use")
 
232
    parser.add_option("-t", "--timeout", type="string", # Parsed later
 
233
                      default="15m",
 
234
                      help="Amount of downtime allowed for clients")
 
235
    parser.add_option("--interval", type="string", # Parsed later
 
236
                      default="5m",
 
237
                      help="How often to check that a client is up")
688
238
    parser.add_option("--check", action="store_true", default=False,
689
239
                      help="Run self-test")
690
 
    parser.add_option("--debug", action="store_true",
691
 
                      help="Debug mode; run in foreground and log to"
692
 
                      " terminal")
693
 
    parser.add_option("--priority", type="string", help="GnuTLS"
694
 
                      " priority string (see GnuTLS documentation)")
695
 
    parser.add_option("--servicename", type="string", metavar="NAME",
696
 
                      help="Zeroconf service name")
697
 
    parser.add_option("--configdir", type="string",
698
 
                      default="/etc/mandos", metavar="DIR",
699
 
                      help="Directory to search for configuration"
700
 
                      " files")
701
240
    (options, args) = parser.parse_args()
702
 
    
 
241
 
703
242
    if options.check:
704
243
        import doctest
705
244
        doctest.testmod()
706
245
        sys.exit()
707
246
    
708
 
    # Default values for config file for server-global settings
709
 
    server_defaults = { "interface": "",
710
 
                        "address": "",
711
 
                        "port": "",
712
 
                        "debug": "False",
713
 
                        "priority":
714
 
                        "SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
715
 
                        "servicename": "Mandos",
716
 
                        }
717
 
    
718
 
    # Parse config file for server-global settings
719
 
    server_config = ConfigParser.SafeConfigParser(server_defaults)
720
 
    del server_defaults
721
 
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
722
 
    # Convert the SafeConfigParser object to a dict
723
 
    server_settings = server_config.defaults()
724
 
    # Use getboolean on the boolean config option
725
 
    server_settings["debug"] = server_config.getboolean\
726
 
                               ("DEFAULT", "debug")
727
 
    del server_config
728
 
    
729
 
    # Override the settings from the config file with command line
730
 
    # options, if set.
731
 
    for option in ("interface", "address", "port", "debug",
732
 
                   "priority", "servicename", "configdir"):
733
 
        value = getattr(options, option)
734
 
        if value is not None:
735
 
            server_settings[option] = value
736
 
    del options
737
 
    # Now we have our good server settings in "server_settings"
738
 
    
739
 
    debug = server_settings["debug"]
740
 
    
741
 
    if not debug:
742
 
        syslogger.setLevel(logging.WARNING)
743
 
        console.setLevel(logging.WARNING)
744
 
    
745
 
    if server_settings["servicename"] != "Mandos":
746
 
        syslogger.setFormatter(logging.Formatter\
747
 
                               ('Mandos (%s): %%(levelname)s:'
748
 
                                ' %%(message)s'
749
 
                                % server_settings["servicename"]))
750
 
    
751
 
    # Parse config file with clients
752
 
    client_defaults = { "timeout": "1h",
753
 
                        "interval": "5m",
754
 
                        "checker": "fping -q -- %(host)s",
755
 
                        "host": "",
756
 
                        }
757
 
    client_config = ConfigParser.SafeConfigParser(client_defaults)
758
 
    client_config.read(os.path.join(server_settings["configdir"],
759
 
                                    "clients.conf"))
760
 
    
761
 
    global service
762
 
    service = AvahiService(name = server_settings["servicename"],
763
 
                           type = "_mandos._tcp", );
764
 
    if server_settings["interface"]:
765
 
        service.interface = if_nametoindex\
766
 
                            (server_settings["interface"])
767
 
    
768
 
    global main_loop
769
 
    global bus
770
 
    global server
771
 
    # From the Avahi example code
772
 
    DBusGMainLoop(set_as_default=True )
773
 
    main_loop = gobject.MainLoop()
774
 
    bus = dbus.SystemBus()
775
 
    server = dbus.Interface(bus.get_object(avahi.DBUS_NAME,
776
 
                                           avahi.DBUS_PATH_SERVER),
777
 
                            avahi.DBUS_INTERFACE_SERVER)
778
 
    # End of Avahi example code
779
 
    
780
 
    clients = Set()
781
 
    def remove_from_clients(client):
782
 
        clients.remove(client)
783
 
        if not clients:
784
 
            logger.critical(u"No clients left, exiting")
785
 
            sys.exit()
786
 
    
787
 
    clients.update(Set(Client(name = section,
788
 
                              stop_hook = remove_from_clients,
789
 
                              config
790
 
                              = dict(client_config.items(section)))
791
 
                       for section in client_config.sections()))
792
 
    if not clients:
793
 
        logger.critical(u"No clients defined")
794
 
        sys.exit(1)
795
 
    
796
 
    if debug:
797
 
        # Redirect stdin so all checkers get /dev/null
798
 
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
799
 
        os.dup2(null, sys.stdin.fileno())
800
 
        if null > 2:
801
 
            os.close(null)
802
 
    else:
803
 
        # No console logging
804
 
        logger.removeHandler(console)
805
 
        # Close all input and output, do double fork, etc.
806
 
        daemon()
807
 
    
808
 
    pidfilename = "/var/run/mandos/mandos.pid"
809
 
    pid = os.getpid()
810
 
    try:
811
 
        pidfile = open(pidfilename, "w")
812
 
        pidfile.write(str(pid) + "\n")
813
 
        pidfile.close()
814
 
        del pidfile
815
 
    except IOError, err:
816
 
        logger.error(u"Could not write %s file with PID %d",
817
 
                     pidfilename, os.getpid())
818
 
    
819
 
    def cleanup():
820
 
        "Cleanup function; run on exit"
821
 
        global group
822
 
        # From the Avahi example code
823
 
        if not group is None:
824
 
            group.Free()
825
 
            group = None
826
 
        # End of Avahi example code
827
 
        
828
 
        while clients:
829
 
            client = clients.pop()
830
 
            client.stop_hook = None
831
 
            client.stop()
832
 
    
833
 
    atexit.register(cleanup)
834
 
    
835
 
    if not debug:
836
 
        signal.signal(signal.SIGINT, signal.SIG_IGN)
837
 
    signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
838
 
    signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())
839
 
    
 
247
    # Parse the time arguments
 
248
    try:
 
249
        options.timeout = string_to_delta(options.timeout)
 
250
    except ValueError:
 
251
        parser.error("option --timeout: Unparseable time")
 
252
    
 
253
    try:
 
254
        options.interval = string_to_delta(options.interval)
 
255
    except ValueError:
 
256
        parser.error("option --interval: Unparseable time")
 
257
    
 
258
    cert = gnutls.crypto.X509Certificate(open(options.cert).read())
 
259
    key = gnutls.crypto.X509PrivateKey(open(options.key).read())
 
260
    ca = gnutls.crypto.X509Certificate(open(options.ca).read())
 
261
    crl = gnutls.crypto.X509CRL(open(options.crl).read())
 
262
    cred = gnutls.connection.X509Credentials(cert, key, [ca], [crl])
 
263
    
 
264
    # Parse config file
 
265
    defaults = {}
 
266
    client_config_object = ConfigParser.SafeConfigParser(defaults)
 
267
    client_config_object.read("mandos-clients.conf")
 
268
    clients = [Client(name=section, options=options,
 
269
                      **(dict(client_config_object.items(section))))
 
270
               for section in client_config_object.sections()]
 
271
    
 
272
    udp_server = IPv6_UDPServer((in6addr_any, options.port),
 
273
                                udp_handler,
 
274
                                options=options)
 
275
    
 
276
    tcp_server = IPv6_TCPServer((in6addr_any, options.port),
 
277
                                tcp_handler,
 
278
                                options=options,
 
279
                                clients=clients,
 
280
                                credentials=cred)
 
281
    
 
282
    while True:
 
283
        try:
 
284
            input, out, err = select.select((udp_server,
 
285
                                             tcp_server), (), ())
 
286
            if not input:
 
287
                pass
 
288
            else:
 
289
                for obj in input:
 
290
                    obj.handle_request()
 
291
        except KeyboardInterrupt:
 
292
            break
 
293
    
 
294
    # Cleanup here
840
295
    for client in clients:
841
 
        client.start()
842
 
    
843
 
    tcp_server = IPv6_TCPServer((server_settings["address"],
844
 
                                 server_settings["port"]),
845
 
                                tcp_handler,
846
 
                                settings=server_settings,
847
 
                                clients=clients)
848
 
    # Find out what port we got
849
 
    service.port = tcp_server.socket.getsockname()[1]
850
 
    logger.info(u"Now listening on address %r, port %d, flowinfo %d,"
851
 
                u" scope_id %d" % tcp_server.socket.getsockname())
852
 
    
853
 
    #service.interface = tcp_server.socket.getsockname()[3]
854
 
    
855
 
    try:
856
 
        # From the Avahi example code
857
 
        server.connect_to_signal("StateChanged", server_state_changed)
858
 
        try:
859
 
            server_state_changed(server.GetState())
860
 
        except dbus.exceptions.DBusException, error:
861
 
            logger.critical(u"DBusException: %s", error)
862
 
            sys.exit(1)
863
 
        # End of Avahi example code
864
 
        
865
 
        gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
866
 
                             lambda *args, **kwargs:
867
 
                             tcp_server.handle_request\
868
 
                             (*args[2:], **kwargs) or True)
869
 
        
870
 
        logger.debug(u"Starting main loop")
871
 
        main_loop_started = True
872
 
        main_loop.run()
873
 
    except AvahiError, error:
874
 
        logger.critical(u"AvahiError: %s" + unicode(error))
875
 
        sys.exit(1)
876
 
    except KeyboardInterrupt:
877
 
        if debug:
878
 
            print
879
 
 
880
 
if __name__ == '__main__':
 
296
        client.stop_checker()
 
297
 
 
298
 
 
299
if __name__ == "__main__":
881
300
    main()
 
301