summaryrefslogtreecommitdiff
path: root/sleekxmpp/plugins/xep_0065/proxy.py
blob: 89f37399d6c5ccb3b34274c10facea52d8382fc8 (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
import sys
import logging
import struct

from threading import Thread, Event
from hashlib import sha1
from select import select
from uuid import uuid4

from sleekxmpp.plugins.base import base_plugin
from sleekxmpp.xmlstream.handler import Callback
from sleekxmpp.xmlstream.matcher import StanzaPath
from socks import socksocket, PROXY_TYPE_SOCKS5

import stanza

# Registers the sleekxmpp logger
log = logging.getLogger(__name__)


class xep_0065(base_plugin):
    """
    XEP-0065 In-Band Bytestreams
    """

    description = "Socks5 Bytestreams"
    dependencies = set(['xep_0030', ])
    xep = '0065'

    # A dict contains for each SID, the proxy thread currently
    # running.
    proxy_threads = {}

    def plugin_init(self):
        """ Initializes the xep_0065 plugin and all event callbacks.
        """

        # Shortcuts to access to the xep_0030 plugin.
        self.disco = self.xmpp['xep_0030']

        # Handler for the streamhost stanza.
        self.xmpp.registerHandler(
            Callback('In-Band Bytestreams',
                     StanzaPath('iq@type=set/q/streamhost'),
                     self._handle_streamhost))

        # Handler for the streamhost-used stanza.
        self.xmpp.registerHandler(
            Callback('In-Band Bytestreams',
                     StanzaPath('iq@type=result/q/streamhost-used'),
                     self._handle_streamhost_used))

    def handshake(self, to, streamer=None):
        """ Starts the handshake to establish the socks5 bytestreams
        connection.
        """

        # Discovers the proxy.
        self.streamer = streamer or self.discover_proxy()

        # Requester requests network address from the proxy.
        streamhost = self.get_network_address(self.streamer)
        self.proxy_host = streamhost['q']['streamhost']['host']
        self.proxy_port = streamhost['q']['streamhost']['port']

        # Generates the SID for this new handshake.
        sid = uuid4().hex

        # Requester initiates S5B negotation with Target by sending
        # IQ-set that includes the JabberID and network address of
        # StreamHost as well as the StreamID (SID) of the proposed
        # bytestream.
        iq = self.xmpp.Iq(sto=to, stype='set')
        iq['q']['sid'] = sid
        iq['q']['streamhost']['jid'] = self.streamer
        iq['q']['streamhost']['host'] = self.proxy_host
        iq['q']['streamhost']['port'] = self.proxy_port

        # Sends the new IQ.
        return iq.send()

    def discover_proxy(self):
        """ Auto-discovers (using XEP 0030) the available bytestream
        proxy on the XMPP server.

        Returns the JID of the proxy.
        """

        # Gets all disco items.
        disco_items = self.disco.get_items(self.xmpp.server)

        for item in disco_items['disco_items']['items']:
            # For each items, gets the disco info.
            disco_info = self.disco.get_info(item[0])

            # Gets and verifies if the identity is a bytestream proxy.
            identities = disco_info['disco_info']['identities']
            for identity in identities:
                if identity[0] == 'proxy' and identity[1] == 'bytestreams':
                    # Returns when the first occurence is found.
                    return '%s' % disco_info['from']

    def get_network_address(self, streamer):
        """ Gets the streamhost information of the proxy.

        streamer : The jid of the proxy.
        """

        iq = self.xmpp.Iq(sto=streamer, stype='get')
        iq['q']  # Adds the query eleme to the iq.

        return iq.send()

    def _handle_streamhost(self, iq):
        """ Handles all streamhost stanzas.
        """

        # Registers the streamhost info.
        self.streamer = iq['q']['streamhost']['jid']
        self.proxy_host = iq['q']['streamhost']['host']
        self.proxy_port = iq['q']['streamhost']['port']

        # Sets the SID, the requester and the target.
        sid = iq['q']['sid']
        requester = '%s' % iq['from']
        target = '%s' % self.xmpp.boundjid

        # Next the Target attempts to open a standard TCP socket on
        # the network address of the Proxy.
        self.proxy_thread = Proxy(sid, requester, target, self.proxy_host,
                                  self.proxy_port, self.on_recv)
        self.proxy_thread.start()

        # Registers the new thread in the proxy_thread dict.
        self.proxy_threads[sid] = self.proxy_thread

        # Wait until the proxy is connected
        self.proxy_thread.connected.wait()

        # Replies to the incoming iq with a streamhost-used stanza.
        res_iq = iq.reply()
        res_iq['q']['sid'] = sid
        res_iq['q']['streamhost-used']['jid'] = self.streamer

        # Sends the IQ
        return res_iq.send()

    def _handle_streamhost_used(self, iq):
        """ Handles all streamhost-used stanzas.
        """

        # Sets the SID, the requester and the target.
        sid = iq['q']['sid']
        requester = '%s' % self.xmpp.boundjid
        target  = '%s' % iq['from']

        # The Requester will establish a connection to the SOCKS5
        # proxy in the same way the Target did.
        self.proxy_thread = Proxy(sid, requester, target, self.proxy_host,
                                  self.proxy_port, self.on_recv)
        self.proxy_thread.start()

        # Registers the new thread in the proxy_thread dict.
        self.proxy_threads[sid] = self.proxy_thread

        # Wait until the proxy is connected
        self.proxy_thread.connected.wait()

        # Requester sends IQ-set to StreamHost requesting that
        # StreamHost activate the bytestream associated with the
        # StreamID.
        self.activate(iq['q']['sid'], target)

    def activate(self, sid, to):
        """ IQ-set to StreamHost requesting that StreamHost activate
        the bytestream associated with the StreamID.
        """

        # Creates the activate IQ.
        act_iq = self.xmpp.Iq(sto=self.streamer, stype='set')
        act_iq['q']['sid'] = sid
        act_iq['q']['activate'] = to

        # Send the IQ.
        act_iq.send()

    def deactivate(self, sid):
        """ Closes the Proxy thread associated to this SID.
        """

        proxy = self.proxy_threads.get(sid)
        if proxy:
            proxy.s.close()
            del self.proxy_threads[sid]

    def close(self):
        """ Closes all Proxy threads.
        """

        for sid, proxy in self.proxy_threads.items():
            proxy.s.close()
            del self.proxy_threads[sid]

    def send(self, sid, data):
        """ Sends the data over the Proxy socket associated to the
        SID.
        """

        proxy = self.proxy_threads.get(sid)
        if proxy:
            proxy.s.sendall(data)

    def on_recv(self, sid, data):
        """ Calls when data is recv from the Proxy socket associated
        to the SID.
        """

        proxy = self.proxy_threads.get(sid)
        if proxy:
            if not data:
                self.xmpp.event('socks_closed', sid)
            else:
                self.xmpp.event('socks_recv', data)


class Proxy(Thread):
    """ Establishes in a thread a connection between the client and
    the server-side Socks5 proxy.
    """

    def __init__(self, sid, requester, target, proxy, proxy_port,
                 on_recv):
        """ Initializes the proxy thread.

        sid        : The StreamID. <str>
        requester  : The JID of the requester. <str>
        target     : The JID of the target. <str>
        proxy_host : The hostname or the IP of the proxy. <str>
        proxy_port : The port of the proxy. <str> or <int>
        on_recv    : A callback called when data are received from the
                     socket. <Callable>
        """

        # Initializes the thread.
        Thread.__init__(self)

        # Because the xep_0065 plugin uses the proxy_port as string,
        # the Proxy class accepts the proxy_port argument as a string
        # or an integer. Here, we force to use the port as an integer.
        proxy_port = int(proxy_port)

        # Creates a connected event to warn when to proxy is
        # connected.
        self.connected = Event()

        # Registers the arguments.
        self.sid = sid
        self.requester = requester
        self.target = target
        self.proxy = proxy
        self.proxy_port = proxy_port
        self.on_recv = on_recv

    def run(self):
        """ Starts the thread.
        """

        # Creates the socks5 proxy socket
        self.s = socksocket()
        self.s.setproxy(PROXY_TYPE_SOCKS5, self.proxy, port=self.proxy_port)

        # The hostname MUST be SHA1(SID + Requester JID + Target JID)
        # where the output is hexadecimal-encoded (not binary).
        digest = sha1()
        digest.update(self.sid)  # SID
        digest.update(self.requester)  # Requester JID
        digest.update(self.target)  # Target JID

        # Computes the digest in hex.
        dest = '%s' % digest.hexdigest()

        # The port MUST be 0.
        self.s.connect((dest, 0))
        log.info('Socket connected.')
        self.connected.set()

        # Blocks until the socket need to be closed.
        self.listen()

        # Closes the socket.
        self.s.close()
        log.info('Socket closed.')

    def listen(self):
        """ Listen for data on the socket. When receiving data, call
        the callback on_recv callable.
        """

        socket_open = True
        while socket_open:
            ins = []
            try:
                # Wait any read available data on socket. Timeout
                # after 5 secs.
                ins, out, err = select([self.s, ], [], [], 5)
            except Exception, e:
                # There's an error with the socket (maybe the socket
                # has been closed and the file descriptor is bad).
                log.debug('Socket error: %s' % e)
                break

            for s in ins:
                data = self.recv_size(self.s)
                if not data:
                    socket_open = False

                self.on_recv(self.sid, data)

    def recv_size(self, the_socket):
        total_len = 0
        total_data = []
        size = sys.maxint
        size_data = sock_data = ''
        recv_size = 8192

        while total_len < size:
            sock_data = the_socket.recv(recv_size)
            if not sock_data:
                return ''.join(total_data)

            if not total_data:
                if len(sock_data) > 4:
                    size_data += sock_data
                    size = struct.unpack('>i', size_data[:4])[0]
                    recv_size = size
                    if recv_size > 524288:
                        recv_size = 524288
                    total_data.append(size_data[4:])
                else:
                    size_data += sock_data
            else:
                total_data.append(sock_data)
            total_len = sum([len(i) for i in total_data])
        return ''.join(total_data)