summaryrefslogtreecommitdiff
path: root/src/leap/bitmask/vpn/process.py
blob: 35ccf9f6cb6374178d3bae6907fc4b7c019e11e5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
# -*- coding: utf-8 -*-
# process.py
# Copyright (C) 2013-2017 LEAP
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

"""
VPN Process management.

A custom processProtocol launches the VPNProcess and connects to its management
interface.
"""

import os
import shutil
import sys
import time
from collections import OrderedDict

from twisted.internet import protocol, reactor, defer
from twisted.internet import error as internet_error
from twisted.internet.endpoints import clientFromString, connectProtocol
from twisted.logger import Logger
from zope.interface import implementer

from leap.bitmask.vpn.utils import get_vpn_launcher
from leap.bitmask.vpn.management import ManagementProtocol
from leap.bitmask.vpn.launchers import darwin
from leap.bitmask.vpn.constants import IS_MAC, IS_LINUX
from leap.common.events import catalog, emit_async

from zope.interface import Interface

from ._state import State


OPENVPN_VERBOSITY = 4


class IStateListener(Interface):

    def changeState(self, state):
        pass

    def appendToStateLog(self, state):
        pass

    def getState(sef):
        pass

    def getStateHistory(self):
        pass


@implementer(IStateListener)
class _VPNProcess(protocol.ProcessProtocol):

    """
    A ProcessProtocol class that can be used to spawn a process that will
    launch openvpn and connect to its management interface to control it
    programmatically.
    """

    log = Logger()

    # HACK - reactor is expected to set this up when the process is spawned.
    # should try to get it from the management protocol instead.
    # XXX or, at least, we can check if they match.
    pid = None

    # TODO do we really need the vpnconfig/providerconfig objects in here???

    def __init__(self, vpnconfig, providerconfig, socket_host, socket_port,
                 openvpn_verb, remotes, restartfun=None):
        """
        :param vpnconfig: vpn configuration object
        :type vpnconfig: VPNConfig

        :param providerconfig: provider specific configuration
        :type providerconfig: ProviderConfig

        :param socket_host: either socket path (unix) or socket IP
        :type socket_host: str

        :param socket_port: either string "unix" if it's a unix
                            socket, or port otherwise
        :type socket_port: str
        """
        self._host = socket_host
        self._port = socket_port

        if socket_port == 'unix':
            folder = os.path.split(self._host)[0]
            if not os.path.isdir(folder):
                os.makedirs(folder)
            self._management_endpoint = clientFromString(
                reactor, b"unix:path=%s" % socket_host)
        else:
            raise ValueError('tcp endpoint not configured')

        self._vpnconfig = vpnconfig
        self._providerconfig = providerconfig
        self._launcher = get_vpn_launcher()
        self._restartfun = restartfun

        self.restarting = True
        self.failed = False
        self.errmsg = None
        self.proto = None
        self._remotes = remotes
        self._statelog = OrderedDict()
        self._turn_state_off()

    def _turn_state_off(self):
        ts = time.time()
        off = State('OFF', ts)
        self.changeState(off)

    # IStateListener methods

    def changeState(self, state):
        self.appendToStateLog(state)
        emit_async(catalog.VPN_STATUS_CHANGED, state.simple)

    def appendToStateLog(self, state):
        ts = state.timestamp
        self._statelog[ts] = state

    def getState(self):
        if self._statelog.values():
            return self._statelog.values()[-1]
        else:
            return None

    # TODO -- expose on the API, wanted by UI
    def getStateHistory(self):
        return self._statelog

    # processProtocol methods

    def outReceived(self, data):
        # use this to debug failed invocations.
        # print("DEBUG VPN: %s" % data)
        pass

    @defer.inlineCallbacks
    def _got_management_protocol(self, proto):
        self.proto = proto
        proto.addStateListener(self)

        try:
            yield proto.logOn()
            yield proto.getVersion()
            yield proto.getPid()
            yield proto.stateOn()
            yield proto.byteCount(2)
        except Exception as exc:
            print('[!] Error: %s' % exc)

    def _connect_to_management(self, retries=30):
        if retries == 0:
            self.log.error('Timeout while connecting to management')
            self.failed = True
            return

        def retry(retries):
            ctr = retries - 1
            self.log.warn(
                'Error connecting to management, retrying. '
                'Retries left:  %s' % ctr)
            reactor.callLater(
                0.1, self._connect_to_management, ctr)

        self._d = connectProtocol(
            self._management_endpoint,
            ManagementProtocol(verbose=True))
        self._d.addCallbacks(
            self._got_management_protocol,
            lambda f: retry(retries))

    def connectionMade(self):
        self.failed = False
        reactor.callLater(0.1, self._connect_to_management)

    def processExited(self, failure):
        err = failure.trap(
            internet_error.ProcessDone, internet_error.ProcessTerminated)

        if err == internet_error.ProcessDone:
            pass

        elif err == internet_error.ProcessTerminated:
            self.failed = True
            self.errmsg = failure.value.exitCode
            if self.errmsg:
                self.log.debug('Process Exited, status %d' % (self.errmsg,))
            else:
                self.log.warn('%r' % failure.value)
        if IS_MAC:
            # TODO: need to exit properly!
            self.errmsg = None
        self.proto = None
        self._turn_state_off()

    def processEnded(self, reason):
        """
        Called when the child process exits and all file descriptors associated
        with it have been closed.
        """
        self.proto = None
        exit_code = reason.value.exitCode

        if isinstance(exit_code, int):
            self.log.debug('processEnded, status %d' % (exit_code,))
            if self.restarting:
                self.log.debug('Restarting VPN process')
                self._cleanup()
                self._restartfun()

    def _cleanup(self):
        """
        Remove all temporal files we might have left behind.

        Iif self.port is 'unix', we have created a temporal socket path that,
        under normal circumstances, we should be able to delete.
        """
        if self._port == "unix":
            tempfolder = os.path.split(self._host)[0]
            if tempfolder and os.path.isdir(tempfolder):
                try:
                    shutil.rmtree(tempfolder)
                except OSError:
                    self.log.error(
                        'Could not delete VPN temp folder %s' % tempfolder)

    # status handling

    @property
    def status(self):
        if self.failed:
            return {'status': 'failed', 'error': self.errmsg}
        try:
            state = self.getState()
            if state:
                _status = state.simple.lower()
            status = {'status': _status, 'error': None}
        except AttributeError:
            raise
            # BUG -- glitch due to proto.state transition?
            # still needed?
            # state = self.getState()
            # if state:
            #    _status = state.simple.lower()
            # status = {'status': _status, 'error': None}

        if self.proto and self.proto.traffic:
            remote = self.proto.remote
            rport = self.proto.rport
            status['remote'] = '%s:%s' % (remote, rport)
            down, up = self.proto.traffic.get_rate()
            status['up'] = up
            status['down'] = down
        if status['status'] == 'off' and self.restarting:
            status['status'] = 'starting'
        return status

    # launcher

    def preUp(self):
        self._launcher.kill_previous_openvpn()

    def preDown(self):
        pass

    def getCommand(self):
        """
        Gets the vpn command from the aproppriate launcher.

        Might throw:
            VPNLauncherException,
            OpenVPNNotFoundException.

        :rtype: list of str
        """
        print("GETTING COMMAND", self._launcher)
        try:
            command = self._launcher.get_vpn_command(
                vpnconfig=self._vpnconfig,
                providerconfig=self._providerconfig,
                socket_host=self._host,
                socket_port=self._port,
                remotes=self._remotes)
            print("Command: %s", command)
        except Exception as exc:
            print("ERROR: %r" % exc)

        encoding = sys.getfilesystemencoding()
        print("encoding", encoding)
        for i, c in enumerate(command):
            if not isinstance(c, str):
                command[i] = c.encode(encoding)
        print("command: %s", command)

        self.log.debug("Running VPN with command: ")
        self.log.debug("{0}".format(" ".join(command)))
        return command

    # shutdown

    def terminate(self):
        if self.proto:
            self.proto.signal('SIGTERM')

    def kill(self):
        try:
            self.transport.signalProcess('KILL')
        except internet_error.ProcessExitedAlready:
            self.log.debug('Process Exited Already')

    def terminate_or_kill(self):
        return self._launcher.terminate_or_kill(
            self.terminate, self.kill, self)


if IS_LINUX:

    VPNProcess = _VPNProcess

elif IS_MAC:

    class _VPNCanary(_VPNProcess):

        """
        Special form of _VPNProcess, for Darwin Launcher (windows might end up
        using the same strategy).

        This is a Canary Process that does not run openvpn itself, but it's
        notified by the privileged process when the process dies.

        This is a workaround to allow the state machine to be notified when
        openvpn process is spawned by the privileged helper.
        """

        def setupHelper(self):
            # TODO use get_vpn_launcher instead
            self.helper = darwin.HelperCommand()

        def preUp(self):
            self.setupHelper()
            cmd = self.getVPNCommand()
            self.helper.send('openvpn_start %s' % ' '.join(cmd))

        def preDown(self):
            self.helper.send('openvpn_stop')

        def connectionMade(self):
            self.setupHelper()
            reactor.callLater(2, self.registerPID)
            _VPNProcess.connectionMade(self)

        def registerPID(self):
            cmd = 'openvpn_set_watcher %s' % self.pid
            self.helper.send(cmd)

        def killProcess(self):
            cmd = 'openvpn_force_stop'
            self.helper.send(cmd)

        def getVPNCommand(self):
            vpncmd = _VPNProcess.getCommand(self)
            return vpncmd

        def getCommand(self):
            canary = '''import sys, signal, time
def receive_signal(signum, stack): sys.exit()
signal.signal(signal.SIGTERM, receive_signal)
while True: time.sleep(90)'''
            return ['python', '-c', '%s' % canary]

    VPNProcess = _VPNCanary