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  • Committer: Teddy Hogeborn
  • Date: 2008-06-21 00:53:32 UTC
  • Revision ID: teddy@fukt.bsnet.se-20080621005332-s4scjdpevuso4lsd
* server.py: Bug fix: Do "from __future__ import division".
  (Client.__init__): Bug fix: parse interval string from config file.
  (Client.check_action): Take no arguments.  Print some debugging
  output.  Reset "checker" to None.
  (Client.start_checker): Sleep 10 seconds before pinging to alleviate
  debugging.
  (Client.next_stop): Bug fix: check if "last_seen" and/or "checker"
  is None.
  (Client.still_valid): Bug fix: check if "last_seen" is None.
  (Client.handle): When finding the right password to send, use a list
  comprehension and an index lookup instead of a generator expression to
  a dict.
  (IPv6_TCPServer.request_queue_size): Removed.
  (in6addr_any): Moved inside "main".
  (main): Changed "clients" to be a Set instead of a list.  Bug fix:
  Exit when/if all clients are removed.  Call "select" with all client
  checkers and a suitable timeout.  Add some debugging output.  Start
  new checkers when needed and delete clients which have timed out.

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server.py
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
 
# 
31
2
 
32
3
from __future__ import division
33
4
 
40
11
import gnutls.crypto
41
12
import gnutls.connection
42
13
import gnutls.errors
43
 
import gnutls.library.functions
44
 
import gnutls.library.constants
45
 
import gnutls.library.types
46
14
import ConfigParser
47
15
import sys
48
16
import re
50
18
import signal
51
19
from sets import Set
52
20
import subprocess
53
 
import atexit
54
 
import stat
55
 
import logging
56
 
import logging.handlers
57
 
 
58
 
import dbus
59
 
import gobject
60
 
import avahi
61
 
from dbus.mainloop.glib import DBusGMainLoop
62
 
import ctypes
63
 
 
64
 
 
65
 
logger = logging.Logger('mandos')
66
 
syslogger = logging.handlers.SysLogHandler\
67
 
            (facility = logging.handlers.SysLogHandler.LOG_DAEMON)
68
 
syslogger.setFormatter(logging.Formatter\
69
 
                        ('%(levelname)s: %(message)s'))
70
 
logger.addHandler(syslogger)
71
 
del syslogger
72
 
 
73
 
 
74
 
class AvahiError(Exception):
75
 
    def __init__(self, value):
76
 
        self.value = value
77
 
    def __str__(self):
78
 
        return repr(self.value)
79
 
 
80
 
class AvahiServiceError(AvahiError):
81
 
    pass
82
 
 
83
 
class AvahiGroupError(AvahiError):
84
 
    pass
85
 
 
86
 
 
87
 
class AvahiService(object):
88
 
    """An Avahi (Zeroconf) service.
89
 
    Attributes:
90
 
    interface: integer; avahi.IF_UNSPEC or an interface index.
91
 
               Used to optionally bind to the specified interface.
92
 
    name: string; Example: 'Mandos'
93
 
    type: string; Example: '_mandos._tcp'.
94
 
                  See <http://www.dns-sd.org/ServiceTypes.html>
95
 
    port: integer; what port to announce
96
 
    TXT: list of strings; TXT record for the service
97
 
    domain: string; Domain to publish on, default to .local if empty.
98
 
    host: string; Host to publish records for, default is localhost
99
 
    max_renames: integer; maximum number of renames
100
 
    rename_count: integer; counter so we only rename after collisions
101
 
                  a sensible number of times
102
 
    """
103
 
    def __init__(self, interface = avahi.IF_UNSPEC, name = None,
104
 
                 type = None, port = None, TXT = None, domain = "",
105
 
                 host = "", max_renames = 12):
106
 
        self.interface = interface
107
 
        self.name = name
108
 
        self.type = type
109
 
        self.port = port
110
 
        if TXT is None:
111
 
            self.TXT = []
112
 
        else:
113
 
            self.TXT = TXT
114
 
        self.domain = domain
115
 
        self.host = host
116
 
        self.rename_count = 0
117
 
    def rename(self):
118
 
        """Derived from the Avahi example code"""
119
 
        if self.rename_count >= self.max_renames:
120
 
            logger.critical(u"No suitable service name found after %i"
121
 
                            u" retries, exiting.", rename_count)
122
 
            raise AvahiServiceError("Too many renames")
123
 
        name = server.GetAlternativeServiceName(name)
124
 
        logger.error(u"Changing name to %r ...", name)
125
 
        self.remove()
126
 
        self.add()
127
 
        self.rename_count += 1
128
 
    def remove(self):
129
 
        """Derived from the Avahi example code"""
130
 
        if group is not None:
131
 
            group.Reset()
132
 
    def add(self):
133
 
        """Derived from the Avahi example code"""
134
 
        global group
135
 
        if group is None:
136
 
            group = dbus.Interface\
137
 
                    (bus.get_object(avahi.DBUS_NAME,
138
 
                                    server.EntryGroupNew()),
139
 
                     avahi.DBUS_INTERFACE_ENTRY_GROUP)
140
 
            group.connect_to_signal('StateChanged',
141
 
                                    entry_group_state_changed)
142
 
        logger.debug(u"Adding service '%s' of type '%s' ...",
143
 
                     service.name, service.type)
144
 
        group.AddService(
145
 
                self.interface,         # interface
146
 
                avahi.PROTO_INET6,      # protocol
147
 
                dbus.UInt32(0),         # flags
148
 
                self.name, self.type,
149
 
                self.domain, self.host,
150
 
                dbus.UInt16(self.port),
151
 
                avahi.string_array_to_txt_array(self.TXT))
152
 
        group.Commit()
153
 
 
154
 
# From the Avahi example code:
155
 
group = None                            # our entry group
156
 
# End of Avahi example code
157
 
 
158
21
 
159
22
class Client(object):
160
 
    """A representation of a client host served by this server.
161
 
    Attributes:
162
 
    name:      string; from the config file, used in log messages
163
 
    fingerprint: string (40 or 32 hexadecimal digits); used to
164
 
                 uniquely identify the client
165
 
    secret:    bytestring; sent verbatim (over TLS) to client
166
 
    fqdn:      string (FQDN); available for use by the checker command
167
 
    created:   datetime.datetime(); object creation, not client host
168
 
    last_checked_ok: datetime.datetime() or None if not yet checked OK
169
 
    timeout:   datetime.timedelta(); How long from last_checked_ok
170
 
                                     until this client is invalid
171
 
    interval:  datetime.timedelta(); How often to start a new checker
172
 
    stop_hook: If set, called by stop() as stop_hook(self)
173
 
    checker:   subprocess.Popen(); a running checker process used
174
 
                                   to see if the client lives.
175
 
                                   'None' if no process is running.
176
 
    checker_initiator_tag: a gobject event source tag, or None
177
 
    stop_initiator_tag:    - '' -
178
 
    checker_callback_tag:  - '' -
179
 
    checker_command: string; External command which is run to check if
180
 
                     client lives.  %() expansions are done at
181
 
                     runtime with vars(self) as dict, so that for
182
 
                     instance %(name)s can be used in the command.
183
 
    Private attibutes:
184
 
    _timeout: Real variable for 'timeout'
185
 
    _interval: Real variable for 'interval'
186
 
    _timeout_milliseconds: Used when calling gobject.timeout_add()
187
 
    _interval_milliseconds: - '' -
188
 
    """
189
 
    def _set_timeout(self, timeout):
190
 
        "Setter function for 'timeout' attribute"
191
 
        self._timeout = timeout
192
 
        self._timeout_milliseconds = ((self.timeout.days
193
 
                                       * 24 * 60 * 60 * 1000)
194
 
                                      + (self.timeout.seconds * 1000)
195
 
                                      + (self.timeout.microseconds
196
 
                                         // 1000))
197
 
    timeout = property(lambda self: self._timeout,
198
 
                       _set_timeout)
199
 
    del _set_timeout
200
 
    def _set_interval(self, interval):
201
 
        "Setter function for 'interval' attribute"
202
 
        self._interval = interval
203
 
        self._interval_milliseconds = ((self.interval.days
204
 
                                        * 24 * 60 * 60 * 1000)
205
 
                                       + (self.interval.seconds
206
 
                                          * 1000)
207
 
                                       + (self.interval.microseconds
208
 
                                          // 1000))
209
 
    interval = property(lambda self: self._interval,
210
 
                        _set_interval)
211
 
    del _set_interval
212
 
    def __init__(self, name = None, stop_hook=None, config={}):
213
 
        """Note: the 'checker' key in 'config' sets the
214
 
        'checker_command' attribute and *not* the 'checker'
215
 
        attribute."""
 
23
    def __init__(self, name=None, options=None, dn=None,
 
24
                 password=None, passfile=None, fqdn=None,
 
25
                 timeout=None, interval=-1):
216
26
        self.name = name
217
 
        logger.debug(u"Creating client %r", self.name)
218
 
        # Uppercase and remove spaces from fingerprint for later
219
 
        # comparison purposes with return value from the fingerprint()
220
 
        # function
221
 
        self.fingerprint = config["fingerprint"].upper()\
222
 
                           .replace(u" ", u"")
223
 
        logger.debug(u"  Fingerprint: %s", self.fingerprint)
224
 
        if "secret" in config:
225
 
            self.secret = config["secret"].decode(u"base64")
226
 
        elif "secfile" in config:
227
 
            sf = open(config["secfile"])
228
 
            self.secret = sf.read()
229
 
            sf.close()
 
27
        self.dn = dn
 
28
        if password:
 
29
            self.password = password
 
30
        elif passfile:
 
31
            self.password = open(passfile).readall()
230
32
        else:
231
 
            raise TypeError(u"No secret or secfile for client %s"
232
 
                            % self.name)
233
 
        self.fqdn = config.get("fqdn", "")
 
33
            print "No Password or Passfile in client config file"
 
34
            # raise RuntimeError XXX
 
35
            self.password = "gazonk"
 
36
        self.fqdn = fqdn                # string
234
37
        self.created = datetime.datetime.now()
235
 
        self.last_checked_ok = None
236
 
        self.timeout = string_to_delta(config["timeout"])
237
 
        self.interval = string_to_delta(config["interval"])
238
 
        self.stop_hook = stop_hook
 
38
        self.last_seen = None           # datetime.datetime()
 
39
        if timeout is None:
 
40
            timeout = options.timeout
 
41
        self.timeout = timeout          # datetime.timedelta()
 
42
        if interval == -1:
 
43
            interval = options.interval
 
44
        else:
 
45
            interval = string_to_delta(interval)
 
46
        self.interval = interval        # datetime.timedelta()
 
47
        self.next_check = datetime.datetime.now() # datetime.datetime()
 
48
        # Note: next_check may be in the past if checker is not None
 
49
        self.checker = None             # or a subprocess.Popen()
 
50
    def check_action(self):
 
51
        """The checker said something and might have completed.
 
52
        Check if is has, and take appropriate actions."""
 
53
        if self.checker.poll() is None:
 
54
            # False alarm, no result yet
 
55
            #self.checker.read()
 
56
            #print "Checker for %(name)s said nothing?" % vars(self)
 
57
            return
 
58
        now = datetime.datetime.now()
 
59
        if self.checker.returncode == 0:
 
60
            print "Checker for %(name)s succeeded" % vars(self)
 
61
            self.last_seen = now
 
62
        else:
 
63
            print "Checker for %(name)s failed" % vars(self)
 
64
        while self.next_check <= now:
 
65
            self.next_check += self.interval
239
66
        self.checker = None
240
 
        self.checker_initiator_tag = None
241
 
        self.stop_initiator_tag = None
242
 
        self.checker_callback_tag = None
243
 
        self.check_command = config["checker"]
244
 
    def start(self):
245
 
        """Start this client's checker and timeout hooks"""
246
 
        # Schedule a new checker to be started an 'interval' from now,
247
 
        # and every interval from then on.
248
 
        self.checker_initiator_tag = gobject.timeout_add\
249
 
                                     (self._interval_milliseconds,
250
 
                                      self.start_checker)
251
 
        # Also start a new checker *right now*.
252
 
        self.start_checker()
253
 
        # Schedule a stop() when 'timeout' has passed
254
 
        self.stop_initiator_tag = gobject.timeout_add\
255
 
                                  (self._timeout_milliseconds,
256
 
                                   self.stop)
257
 
    def stop(self):
258
 
        """Stop this client.
259
 
        The possibility that a client might be restarted is left open,
260
 
        but not currently used."""
261
 
        # If this client doesn't have a secret, it is already stopped.
262
 
        if self.secret:
263
 
            logger.info(u"Stopping client %s", self.name)
264
 
            self.secret = None
265
 
        else:
266
 
            return False
267
 
        if getattr(self, "stop_initiator_tag", False):
268
 
            gobject.source_remove(self.stop_initiator_tag)
269
 
            self.stop_initiator_tag = None
270
 
        if getattr(self, "checker_initiator_tag", False):
271
 
            gobject.source_remove(self.checker_initiator_tag)
272
 
            self.checker_initiator_tag = None
 
67
    handle_request = check_action
 
68
    def start_checker(self):
273
69
        self.stop_checker()
274
 
        if self.stop_hook:
275
 
            self.stop_hook(self)
276
 
        # Do not run this again if called by a gobject.timeout_add
277
 
        return False
278
 
    def __del__(self):
279
 
        self.stop_hook = None
280
 
        self.stop()
281
 
    def checker_callback(self, pid, condition):
282
 
        """The checker has completed, so take appropriate actions."""
283
 
        now = datetime.datetime.now()
284
 
        self.checker_callback_tag = None
285
 
        self.checker = None
286
 
        if os.WIFEXITED(condition) \
287
 
               and (os.WEXITSTATUS(condition) == 0):
288
 
            logger.info(u"Checker for %(name)s succeeded",
289
 
                        vars(self))
290
 
            self.last_checked_ok = now
291
 
            gobject.source_remove(self.stop_initiator_tag)
292
 
            self.stop_initiator_tag = gobject.timeout_add\
293
 
                                      (self._timeout_milliseconds,
294
 
                                       self.stop)
295
 
        elif not os.WIFEXITED(condition):
296
 
            logger.warning(u"Checker for %(name)s crashed?",
297
 
                           vars(self))
298
 
        else:
299
 
            logger.info(u"Checker for %(name)s failed",
300
 
                        vars(self))
301
 
    def start_checker(self):
302
 
        """Start a new checker subprocess if one is not running.
303
 
        If a checker already exists, leave it running and do
304
 
        nothing."""
305
 
        # The reason for not killing a running checker is that if we
306
 
        # did that, then if a checker (for some reason) started
307
 
        # running slowly and taking more than 'interval' time, the
308
 
        # client would inevitably timeout, since no checker would get
309
 
        # a chance to run to completion.  If we instead leave running
310
 
        # checkers alone, the checker would have to take more time
311
 
        # than 'timeout' for the client to be declared invalid, which
312
 
        # is as it should be.
313
 
        if self.checker is None:
314
 
            try:
315
 
                # In case check_command has exactly one % operator
316
 
                command = self.check_command % self.fqdn
317
 
            except TypeError:
318
 
                # Escape attributes for the shell
319
 
                escaped_attrs = dict((key, re.escape(str(val)))
320
 
                                     for key, val in
321
 
                                     vars(self).iteritems())
322
 
                try:
323
 
                    command = self.check_command % escaped_attrs
324
 
                except TypeError, error:
325
 
                    logger.error(u'Could not format string "%s":'
326
 
                                 u' %s', self.check_command, error)
327
 
                    return True # Try again later
328
 
            try:
329
 
                logger.info(u"Starting checker %r for %s",
330
 
                            command, self.name)
331
 
                self.checker = subprocess.Popen(command,
332
 
                                                close_fds=True,
333
 
                                                shell=True, cwd="/")
334
 
                self.checker_callback_tag = gobject.child_watch_add\
335
 
                                            (self.checker.pid,
336
 
                                             self.checker_callback)
337
 
            except subprocess.OSError, error:
338
 
                logger.error(u"Failed to start subprocess: %s",
339
 
                             error)
340
 
        # Re-run this periodically if run by gobject.timeout_add
341
 
        return True
 
70
        try:
 
71
            self.checker = subprocess.Popen("sleep 10; fping -q -- %s"
 
72
                                            % re.escape(self.fqdn),
 
73
                                            stdout=subprocess.PIPE,
 
74
                                            close_fds=True,
 
75
                                            shell=True, cwd="/")
 
76
        except subprocess.OSError, e:
 
77
            print "Failed to start subprocess:", e
342
78
    def stop_checker(self):
343
 
        """Force the checker process, if any, to stop."""
344
 
        if self.checker_callback_tag:
345
 
            gobject.source_remove(self.checker_callback_tag)
346
 
            self.checker_callback_tag = None
347
 
        if getattr(self, "checker", None) is None:
 
79
        if self.checker is None:
348
80
            return
349
 
        logger.debug("Stopping checker for %(name)s", vars(self))
350
 
        try:
351
 
            os.kill(self.checker.pid, signal.SIGTERM)
352
 
            #os.sleep(0.5)
353
 
            #if self.checker.poll() is None:
354
 
            #    os.kill(self.checker.pid, signal.SIGKILL)
355
 
        except OSError, error:
356
 
            if error.errno != errno.ESRCH: # No such process
357
 
                raise
 
81
        os.kill(self.checker.pid, signal.SIGTERM)
 
82
        if self.checker.poll() is None:
 
83
            os.kill(self.checker.pid, signal.SIGKILL)
358
84
        self.checker = None
359
 
    def still_valid(self):
360
 
        """Has the timeout not yet passed for this client?"""
361
 
        now = datetime.datetime.now()
362
 
        if self.last_checked_ok is None:
 
85
    __del__ = stop_checker
 
86
    def fileno(self):
 
87
        if self.checker is None:
 
88
            return None
 
89
        return self.checker.stdout.fileno()
 
90
    def next_stop(self):
 
91
        """The time when something must be done about this client
 
92
        May be in the past."""
 
93
        if self.last_seen is None:
 
94
            # This client has never been seen
 
95
            next_timeout = self.created + self.timeout
 
96
        else:
 
97
            next_timeout = self.last_seen + self.timeout
 
98
        if self.checker is None:
 
99
            return min(next_timeout, self.next_check)
 
100
        else:
 
101
            return next_timeout
 
102
    def still_valid(self, now=None):
 
103
        """Has this client's timeout not passed?"""
 
104
        if now is None:
 
105
            now = datetime.datetime.now()
 
106
        if self.last_seen is None:
363
107
            return now < (self.created + self.timeout)
364
108
        else:
365
 
            return now < (self.last_checked_ok + self.timeout)
366
 
 
367
 
 
368
 
def peer_certificate(session):
369
 
    "Return the peer's OpenPGP certificate as a bytestring"
370
 
    # If not an OpenPGP certificate...
371
 
    if gnutls.library.functions.gnutls_certificate_type_get\
372
 
            (session._c_object) \
373
 
           != gnutls.library.constants.GNUTLS_CRT_OPENPGP:
374
 
        # ...do the normal thing
375
 
        return session.peer_certificate
376
 
    list_size = ctypes.c_uint()
377
 
    cert_list = gnutls.library.functions.gnutls_certificate_get_peers\
378
 
        (session._c_object, ctypes.byref(list_size))
379
 
    if list_size.value == 0:
380
 
        return None
381
 
    cert = cert_list[0]
382
 
    return ctypes.string_at(cert.data, cert.size)
383
 
 
384
 
 
385
 
def fingerprint(openpgp):
386
 
    "Convert an OpenPGP bytestring to a hexdigit fingerprint string"
387
 
    # New GnuTLS "datum" with the OpenPGP public key
388
 
    datum = gnutls.library.types.gnutls_datum_t\
389
 
        (ctypes.cast(ctypes.c_char_p(openpgp),
390
 
                     ctypes.POINTER(ctypes.c_ubyte)),
391
 
         ctypes.c_uint(len(openpgp)))
392
 
    # New empty GnuTLS certificate
393
 
    crt = gnutls.library.types.gnutls_openpgp_crt_t()
394
 
    gnutls.library.functions.gnutls_openpgp_crt_init\
395
 
        (ctypes.byref(crt))
396
 
    # Import the OpenPGP public key into the certificate
397
 
    gnutls.library.functions.gnutls_openpgp_crt_import\
398
 
                    (crt, ctypes.byref(datum),
399
 
                     gnutls.library.constants.GNUTLS_OPENPGP_FMT_RAW)
400
 
    # New buffer for the fingerprint
401
 
    buffer = ctypes.create_string_buffer(20)
402
 
    buffer_length = ctypes.c_size_t()
403
 
    # Get the fingerprint from the certificate into the buffer
404
 
    gnutls.library.functions.gnutls_openpgp_crt_get_fingerprint\
405
 
        (crt, ctypes.byref(buffer), ctypes.byref(buffer_length))
406
 
    # Deinit the certificate
407
 
    gnutls.library.functions.gnutls_openpgp_crt_deinit(crt)
408
 
    # Convert the buffer to a Python bytestring
409
 
    fpr = ctypes.string_at(buffer, buffer_length.value)
410
 
    # Convert the bytestring to hexadecimal notation
411
 
    hex_fpr = u''.join(u"%02X" % ord(char) for char in fpr)
412
 
    return hex_fpr
 
109
            return now < (self.last_seen + self.timeout)
 
110
    def it_is_time_to_check(self, now=None):
 
111
        if now is None:
 
112
            now = datetime.datetime.now()
 
113
        return self.next_check <= now
 
114
 
 
115
 
 
116
class server_metaclass(type):
 
117
    "Common behavior for the UDP and TCP server classes"
 
118
    def __new__(cls, name, bases, attrs):
 
119
        attrs["address_family"] = socket.AF_INET6
 
120
        attrs["allow_reuse_address"] = True
 
121
        def server_bind(self):
 
122
            if self.options.interface:
 
123
                if not hasattr(socket, "SO_BINDTODEVICE"):
 
124
                    # From /usr/include/asm-i486/socket.h
 
125
                    socket.SO_BINDTODEVICE = 25
 
126
                try:
 
127
                    self.socket.setsockopt(socket.SOL_SOCKET,
 
128
                                           socket.SO_BINDTODEVICE,
 
129
                                           self.options.interface)
 
130
                except socket.error, error:
 
131
                    if error[0] == errno.EPERM:
 
132
                        print "Warning: No permission to bind to interface", \
 
133
                              self.options.interface
 
134
                    else:
 
135
                        raise error
 
136
            return super(type(self), self).server_bind()
 
137
        attrs["server_bind"] = server_bind
 
138
        def init(self, *args, **kwargs):
 
139
            if "options" in kwargs:
 
140
                self.options = kwargs["options"]
 
141
                del kwargs["options"]
 
142
            if "clients" in kwargs:
 
143
                self.clients = kwargs["clients"]
 
144
                del kwargs["clients"]
 
145
            if "credentials" in kwargs:
 
146
                self.credentials = kwargs["credentials"]
 
147
                del kwargs["credentials"]
 
148
            return super(type(self), self).__init__(*args, **kwargs)
 
149
        attrs["__init__"] = init
 
150
        return type.__new__(cls, name, bases, attrs)
 
151
 
 
152
 
 
153
class udp_handler(SocketServer.DatagramRequestHandler, object):
 
154
    def handle(self):
 
155
        self.wfile.write("Polo")
 
156
        print "UDP request answered"
 
157
 
 
158
 
 
159
class IPv6_UDPServer(SocketServer.UDPServer, object):
 
160
    __metaclass__ = server_metaclass
 
161
    def verify_request(self, request, client_address):
 
162
        print "UDP request came"
 
163
        return request[0] == "Marco"
413
164
 
414
165
 
415
166
class tcp_handler(SocketServer.BaseRequestHandler, object):
416
 
    """A TCP request handler class.
417
 
    Instantiated by IPv6_TCPServer for each request to handle it.
418
 
    Note: This will run in its own forked process."""
419
 
    
420
167
    def handle(self):
421
 
        logger.info(u"TCP connection from: %s",
422
 
                     unicode(self.client_address))
423
 
        session = gnutls.connection.ClientSession\
424
 
                  (self.request, gnutls.connection.X509Credentials())
425
 
        
426
 
        line = self.request.makefile().readline()
427
 
        logger.debug(u"Protocol version: %r", line)
428
 
        try:
429
 
            if int(line.strip().split()[0]) > 1:
430
 
                raise RuntimeError
431
 
        except (ValueError, IndexError, RuntimeError), error:
432
 
            logger.error(u"Unknown protocol version: %s", error)
433
 
            return
434
 
        
435
 
        # Note: gnutls.connection.X509Credentials is really a generic
436
 
        # GnuTLS certificate credentials object so long as no X.509
437
 
        # keys are added to it.  Therefore, we can use it here despite
438
 
        # using OpenPGP certificates.
439
 
        
440
 
        #priority = ':'.join(("NONE", "+VERS-TLS1.1", "+AES-256-CBC",
441
 
        #                "+SHA1", "+COMP-NULL", "+CTYPE-OPENPGP",
442
 
        #                "+DHE-DSS"))
443
 
        priority = "NORMAL"             # Fallback default, since this
444
 
                                        # MUST be set.
445
 
        if self.server.settings["priority"]:
446
 
            priority = self.server.settings["priority"]
447
 
        gnutls.library.functions.gnutls_priority_set_direct\
448
 
            (session._c_object, priority, None);
449
 
        
450
 
        try:
451
 
            session.handshake()
452
 
        except gnutls.errors.GNUTLSError, error:
453
 
            logger.warning(u"Handshake failed: %s", error)
454
 
            # Do not run session.bye() here: the session is not
455
 
            # established.  Just abandon the request.
456
 
            return
457
 
        try:
458
 
            fpr = fingerprint(peer_certificate(session))
459
 
        except (TypeError, gnutls.errors.GNUTLSError), error:
460
 
            logger.warning(u"Bad certificate: %s", error)
461
 
            session.bye()
462
 
            return
463
 
        logger.debug(u"Fingerprint: %s", fpr)
464
 
        client = None
465
 
        for c in self.server.clients:
466
 
            if c.fingerprint == fpr:
467
 
                client = c
468
 
                break
469
 
        if not client:
470
 
            logger.warning(u"Client not found for fingerprint: %s",
471
 
                           fpr)
472
 
            session.bye()
473
 
            return
474
 
        # Have to check if client.still_valid(), since it is possible
475
 
        # that the client timed out while establishing the GnuTLS
476
 
        # session.
477
 
        if not client.still_valid():
478
 
            logger.warning(u"Client %(name)s is invalid",
479
 
                           vars(client))
480
 
            session.bye()
481
 
            return
482
 
        sent_size = 0
483
 
        while sent_size < len(client.secret):
484
 
            sent = session.send(client.secret[sent_size:])
485
 
            logger.debug(u"Sent: %d, remaining: %d",
486
 
                         sent, len(client.secret)
487
 
                         - (sent_size + sent))
488
 
            sent_size += sent
 
168
        print "TCP request came"
 
169
        print "Request:", self.request
 
170
        print "Client Address:", self.client_address
 
171
        print "Server:", self.server
 
172
        session = gnutls.connection.ServerSession(self.request,
 
173
                                                  self.server.credentials)
 
174
        session.handshake()
 
175
        if session.peer_certificate:
 
176
            print "DN:", session.peer_certificate.subject
 
177
        try:
 
178
            session.verify_peer()
 
179
        except gnutls.errors.CertificateError, error:
 
180
            print "Verify failed", error
 
181
            session.bye()
 
182
            return
 
183
        try:
 
184
            session.send([client.password
 
185
                          for client in self.server.clients
 
186
                          if (client.dn ==
 
187
                              session.peer_certificate.subject)][0])
 
188
        except IndexError:
 
189
            session.send("gazonk")
 
190
            # Log maybe? XXX
489
191
        session.bye()
490
192
 
491
193
 
492
194
class IPv6_TCPServer(SocketServer.ForkingTCPServer, object):
493
 
    """IPv6 TCP server.  Accepts 'None' as address and/or port.
494
 
    Attributes:
495
 
        settings:       Server settings
496
 
        clients:        Set() of Client objects
497
 
    """
498
 
    address_family = socket.AF_INET6
499
 
    def __init__(self, *args, **kwargs):
500
 
        if "settings" in kwargs:
501
 
            self.settings = kwargs["settings"]
502
 
            del kwargs["settings"]
503
 
        if "clients" in kwargs:
504
 
            self.clients = kwargs["clients"]
505
 
            del kwargs["clients"]
506
 
        return super(type(self), self).__init__(*args, **kwargs)
507
 
    def server_bind(self):
508
 
        """This overrides the normal server_bind() function
509
 
        to bind to an interface if one was specified, and also NOT to
510
 
        bind to an address or port if they were not specified."""
511
 
        if self.settings["interface"]:
512
 
            # 25 is from /usr/include/asm-i486/socket.h
513
 
            SO_BINDTODEVICE = getattr(socket, "SO_BINDTODEVICE", 25)
514
 
            try:
515
 
                self.socket.setsockopt(socket.SOL_SOCKET,
516
 
                                       SO_BINDTODEVICE,
517
 
                                       self.settings["interface"])
518
 
            except socket.error, error:
519
 
                if error[0] == errno.EPERM:
520
 
                    logger.error(u"No permission to"
521
 
                                 u" bind to interface %s",
522
 
                                 self.settings["interface"])
523
 
                else:
524
 
                    raise error
525
 
        # Only bind(2) the socket if we really need to.
526
 
        if self.server_address[0] or self.server_address[1]:
527
 
            if not self.server_address[0]:
528
 
                in6addr_any = "::"
529
 
                self.server_address = (in6addr_any,
530
 
                                       self.server_address[1])
531
 
            elif self.server_address[1] is None:
532
 
                self.server_address = (self.server_address[0],
533
 
                                       0)
534
 
            return super(type(self), self).server_bind()
 
195
    __metaclass__ = server_metaclass
535
196
 
536
197
 
537
198
def string_to_delta(interval):
568
229
    return delta
569
230
 
570
231
 
571
 
def server_state_changed(state):
572
 
    """Derived from the Avahi example code"""
573
 
    if state == avahi.SERVER_COLLISION:
574
 
        logger.error(u"Server name collision")
575
 
        service.remove()
576
 
    elif state == avahi.SERVER_RUNNING:
577
 
        service.add()
578
 
 
579
 
 
580
 
def entry_group_state_changed(state, error):
581
 
    """Derived from the Avahi example code"""
582
 
    logger.debug(u"state change: %i", state)
583
 
    
584
 
    if state == avahi.ENTRY_GROUP_ESTABLISHED:
585
 
        logger.debug(u"Service established.")
586
 
    elif state == avahi.ENTRY_GROUP_COLLISION:
587
 
        logger.warning(u"Service name collision.")
588
 
        service.rename()
589
 
    elif state == avahi.ENTRY_GROUP_FAILURE:
590
 
        logger.critical(u"Error in group state changed %s",
591
 
                        unicode(error))
592
 
        raise AvahiGroupError("State changed: %s", str(error))
593
 
 
594
 
def if_nametoindex(interface):
595
 
    """Call the C function if_nametoindex(), or equivalent"""
596
 
    global if_nametoindex
597
 
    try:
598
 
        if "ctypes.util" not in sys.modules:
599
 
            import ctypes.util
600
 
        if_nametoindex = ctypes.cdll.LoadLibrary\
601
 
            (ctypes.util.find_library("c")).if_nametoindex
602
 
    except (OSError, AttributeError):
603
 
        if "struct" not in sys.modules:
604
 
            import struct
605
 
        if "fcntl" not in sys.modules:
606
 
            import fcntl
607
 
        def if_nametoindex(interface):
608
 
            "Get an interface index the hard way, i.e. using fcntl()"
609
 
            SIOCGIFINDEX = 0x8933  # From /usr/include/linux/sockios.h
610
 
            s = socket.socket()
611
 
            ifreq = fcntl.ioctl(s, SIOCGIFINDEX,
612
 
                                struct.pack("16s16x", interface))
613
 
            s.close()
614
 
            interface_index = struct.unpack("I", ifreq[16:20])[0]
615
 
            return interface_index
616
 
    return if_nametoindex(interface)
617
 
 
618
 
 
619
 
def daemon(nochdir = False, noclose = False):
620
 
    """See daemon(3).  Standard BSD Unix function.
621
 
    This should really exist as os.daemon, but it doesn't (yet)."""
622
 
    if os.fork():
623
 
        sys.exit()
624
 
    os.setsid()
625
 
    if not nochdir:
626
 
        os.chdir("/")
627
 
    if os.fork():
628
 
        sys.exit()
629
 
    if not noclose:
630
 
        # Close all standard open file descriptors
631
 
        null = os.open(os.path.devnull, os.O_NOCTTY | os.O_RDWR)
632
 
        if not stat.S_ISCHR(os.fstat(null).st_mode):
633
 
            raise OSError(errno.ENODEV,
634
 
                          "/dev/null not a character device")
635
 
        os.dup2(null, sys.stdin.fileno())
636
 
        os.dup2(null, sys.stdout.fileno())
637
 
        os.dup2(null, sys.stderr.fileno())
638
 
        if null > 2:
639
 
            os.close(null)
640
 
 
641
 
 
642
232
def main():
643
 
    global main_loop_started
644
 
    main_loop_started = False
645
 
    
646
233
    parser = OptionParser()
647
234
    parser.add_option("-i", "--interface", type="string",
648
 
                      metavar="IF", help="Bind to interface IF")
649
 
    parser.add_option("-a", "--address", type="string",
650
 
                      help="Address to listen for requests on")
651
 
    parser.add_option("-p", "--port", type="int",
 
235
                      default="eth0", metavar="IF",
 
236
                      help="Interface to bind to")
 
237
    parser.add_option("--cert", type="string", default="cert.pem",
 
238
                      metavar="FILE",
 
239
                      help="Public key certificate to use")
 
240
    parser.add_option("--key", type="string", default="key.pem",
 
241
                      metavar="FILE",
 
242
                      help="Private key to use")
 
243
    parser.add_option("--ca", type="string", default="ca.pem",
 
244
                      metavar="FILE",
 
245
                      help="Certificate Authority certificate to use")
 
246
    parser.add_option("--crl", type="string", default="crl.pem",
 
247
                      metavar="FILE",
 
248
                      help="Certificate Revokation List to use")
 
249
    parser.add_option("-p", "--port", type="int", default=49001,
652
250
                      help="Port number to receive requests on")
 
251
    parser.add_option("--dh", type="int", metavar="BITS",
 
252
                      help="DH group to use")
 
253
    parser.add_option("-t", "--timeout", type="string", # Parsed later
 
254
                      default="15m",
 
255
                      help="Amount of downtime allowed for clients")
 
256
    parser.add_option("--interval", type="string", # Parsed later
 
257
                      default="5m",
 
258
                      help="How often to check that a client is up")
653
259
    parser.add_option("--check", action="store_true", default=False,
654
260
                      help="Run self-test")
655
 
    parser.add_option("--debug", action="store_true", default=False,
656
 
                      help="Debug mode; run in foreground and log to"
657
 
                      " terminal")
658
 
    parser.add_option("--priority", type="string", help="GnuTLS"
659
 
                      " priority string (see GnuTLS documentation)")
660
 
    parser.add_option("--servicename", type="string", metavar="NAME",
661
 
                      help="Zeroconf service name")
662
 
    parser.add_option("--configdir", type="string",
663
 
                      default="/etc/mandos", metavar="DIR",
664
 
                      help="Directory to search for configuration"
665
 
                      " files")
666
261
    (options, args) = parser.parse_args()
667
 
    
 
262
 
668
263
    if options.check:
669
264
        import doctest
670
265
        doctest.testmod()
671
266
        sys.exit()
672
267
    
673
 
    # Default values for config file for server-global settings
674
 
    server_defaults = { "interface": "",
675
 
                        "address": "",
676
 
                        "port": "",
677
 
                        "debug": "False",
678
 
                        "priority":
679
 
                        "SECURE256:!CTYPE-X.509:+CTYPE-OPENPGP",
680
 
                        "servicename": "Mandos",
681
 
                        }
682
 
    
683
 
    # Parse config file for server-global settings
684
 
    server_config = ConfigParser.SafeConfigParser(server_defaults)
685
 
    del server_defaults
686
 
    server_config.read(os.path.join(options.configdir, "mandos.conf"))
687
 
    server_section = "server"
688
 
    # Convert the SafeConfigParser object to a dict
689
 
    server_settings = dict(server_config.items(server_section))
690
 
    # Use getboolean on the boolean config option
691
 
    server_settings["debug"] = server_config.getboolean\
692
 
                               (server_section, "debug")
693
 
    del server_config
694
 
    
695
 
    # Override the settings from the config file with command line
696
 
    # options, if set.
697
 
    for option in ("interface", "address", "port", "debug",
698
 
                   "priority", "servicename", "configdir"):
699
 
        value = getattr(options, option)
700
 
        if value is not None:
701
 
            server_settings[option] = value
702
 
    del options
703
 
    # Now we have our good server settings in "server_settings"
704
 
    
705
 
    # Parse config file with clients
706
 
    client_defaults = { "timeout": "1h",
707
 
                        "interval": "5m",
708
 
                        "checker": "fping -q -- %%(fqdn)s",
709
 
                        }
710
 
    client_config = ConfigParser.SafeConfigParser(client_defaults)
711
 
    client_config.read(os.path.join(server_settings["configdir"],
712
 
                                    "clients.conf"))
713
 
    
714
 
    global service
715
 
    service = AvahiService(name = server_settings["servicename"],
716
 
                           type = "_mandos._tcp", );
717
 
    if server_settings["interface"]:
718
 
        service.interface = if_nametoindex(server_settings["interface"])
719
 
    
720
 
    global main_loop
721
 
    global bus
722
 
    global server
723
 
    # From the Avahi example code
724
 
    DBusGMainLoop(set_as_default=True )
725
 
    main_loop = gobject.MainLoop()
726
 
    bus = dbus.SystemBus()
727
 
    server = dbus.Interface(
728
 
            bus.get_object( avahi.DBUS_NAME, avahi.DBUS_PATH_SERVER ),
729
 
            avahi.DBUS_INTERFACE_SERVER )
730
 
    # End of Avahi example code
731
 
    
732
 
    debug = server_settings["debug"]
733
 
    
734
 
    if debug:
735
 
        console = logging.StreamHandler()
736
 
        # console.setLevel(logging.DEBUG)
737
 
        console.setFormatter(logging.Formatter\
738
 
                             ('%(levelname)s: %(message)s'))
739
 
        logger.addHandler(console)
740
 
        del console
741
 
    
742
 
    clients = Set()
743
 
    def remove_from_clients(client):
744
 
        clients.remove(client)
 
268
    # Parse the time arguments
 
269
    try:
 
270
        options.timeout = string_to_delta(options.timeout)
 
271
    except ValueError:
 
272
        parser.error("option --timeout: Unparseable time")
 
273
    
 
274
    try:
 
275
        options.interval = string_to_delta(options.interval)
 
276
    except ValueError:
 
277
        parser.error("option --interval: Unparseable time")
 
278
    
 
279
    cert = gnutls.crypto.X509Certificate(open(options.cert).read())
 
280
    key = gnutls.crypto.X509PrivateKey(open(options.key).read())
 
281
    ca = gnutls.crypto.X509Certificate(open(options.ca).read())
 
282
    crl = gnutls.crypto.X509CRL(open(options.crl).read())
 
283
    cred = gnutls.connection.X509Credentials(cert, key, [ca], [crl])
 
284
    
 
285
    # Parse config file
 
286
    defaults = {}
 
287
    client_config_object = ConfigParser.SafeConfigParser(defaults)
 
288
    client_config_object.read("mandos-clients.conf")
 
289
    clients = Set(Client(name=section, options=options,
 
290
                         **(dict(client_config_object\
 
291
                                 .items(section))))
 
292
                  for section in client_config_object.sections())
 
293
    
 
294
    in6addr_any = "::"
 
295
    udp_server = IPv6_UDPServer((in6addr_any, options.port),
 
296
                                udp_handler,
 
297
                                options=options)
 
298
    
 
299
    tcp_server = IPv6_TCPServer((in6addr_any, options.port),
 
300
                                tcp_handler,
 
301
                                options=options,
 
302
                                clients=clients,
 
303
                                credentials=cred)
 
304
    
 
305
    while True:
745
306
        if not clients:
746
 
            logger.critical(u"No clients left, exiting")
747
 
            sys.exit()
748
 
    
749
 
    clients.update(Set(Client(name = section,
750
 
                              stop_hook = remove_from_clients,
751
 
                              config
752
 
                              = dict(client_config.items(section)))
753
 
                       for section in client_config.sections()))
754
 
    
755
 
    if not debug:
756
 
        daemon()
757
 
    
758
 
    def cleanup():
759
 
        "Cleanup function; run on exit"
760
 
        global group
761
 
        # From the Avahi example code
762
 
        if not group is None:
763
 
            group.Free()
764
 
            group = None
765
 
        # End of Avahi example code
766
 
        
767
 
        while clients:
768
 
            client = clients.pop()
769
 
            client.stop_hook = None
770
 
            client.stop()
771
 
    
772
 
    atexit.register(cleanup)
773
 
    
774
 
    if not debug:
775
 
        signal.signal(signal.SIGINT, signal.SIG_IGN)
776
 
    signal.signal(signal.SIGHUP, lambda signum, frame: sys.exit())
777
 
    signal.signal(signal.SIGTERM, lambda signum, frame: sys.exit())
778
 
    
 
307
            break
 
308
        try:
 
309
            next_stop = min(client.next_stop() for client in clients)
 
310
            now = datetime.datetime.now()
 
311
            if next_stop > now:
 
312
                delay = next_stop - now
 
313
                delay_seconds = (delay.days * 24 * 60 * 60
 
314
                                 + delay.seconds
 
315
                                 + delay.microseconds / 1000000)
 
316
                clients_with_checkers = tuple(client for client in
 
317
                                              clients
 
318
                                              if client.checker
 
319
                                              is not None)
 
320
                input_checks = (udp_server, tcp_server) \
 
321
                               + clients_with_checkers
 
322
                print "Waiting for network",
 
323
                if clients_with_checkers:
 
324
                    print "and checkers for:",
 
325
                    for client in clients_with_checkers:
 
326
                        print client.name,
 
327
                print
 
328
                input, out, err = select.select(input_checks, (), (),
 
329
                                                delay_seconds)
 
330
                for obj in input:
 
331
                    obj.handle_request()
 
332
            # start new checkers
 
333
            for client in clients:
 
334
                if client.it_is_time_to_check(now=now) and \
 
335
                       client.checker is None:
 
336
                    print "Starting checker for client %(name)s" \
 
337
                          % vars(client)
 
338
                    client.start_checker()
 
339
            # delete timed-out clients
 
340
            for client in clients.copy():
 
341
                if not client.still_valid(now=now):
 
342
                    # log xxx
 
343
                    print "Removing client %(name)s" % vars(client)
 
344
                    clients.remove(client)
 
345
        except KeyboardInterrupt:
 
346
            break
 
347
    
 
348
    # Cleanup here
779
349
    for client in clients:
780
 
        client.start()
781
 
    
782
 
    tcp_server = IPv6_TCPServer((server_settings["address"],
783
 
                                 server_settings["port"]),
784
 
                                tcp_handler,
785
 
                                settings=server_settings,
786
 
                                clients=clients)
787
 
    # Find out what port we got
788
 
    service.port = tcp_server.socket.getsockname()[1]
789
 
    logger.info(u"Now listening on address %r, port %d, flowinfo %d,"
790
 
                u" scope_id %d" % tcp_server.socket.getsockname())
791
 
    
792
 
    #service.interface = tcp_server.socket.getsockname()[3]
793
 
    
794
 
    try:
795
 
        # From the Avahi example code
796
 
        server.connect_to_signal("StateChanged", server_state_changed)
797
 
        try:
798
 
            server_state_changed(server.GetState())
799
 
        except dbus.exceptions.DBusException, error:
800
 
            logger.critical(u"DBusException: %s", error)
801
 
            sys.exit(1)
802
 
        # End of Avahi example code
803
 
        
804
 
        gobject.io_add_watch(tcp_server.fileno(), gobject.IO_IN,
805
 
                             lambda *args, **kwargs:
806
 
                             tcp_server.handle_request\
807
 
                             (*args[2:], **kwargs) or True)
808
 
        
809
 
        logger.debug("Starting main loop")
810
 
        main_loop_started = True
811
 
        main_loop.run()
812
 
    except AvahiError, error:
813
 
        logger.critical(u"AvahiError: %s" + unicode(error))
814
 
        sys.exit(1)
815
 
    except KeyboardInterrupt:
816
 
        if debug:
817
 
            print
818
 
 
819
 
if __name__ == '__main__':
 
350
        client.stop_checker()
 
351
 
 
352
 
 
353
if __name__ == "__main__":
820
354
    main()
 
355