slixmpp/sleekxmpp/plugins/xep_0065/proxy.py
2012-06-07 18:38:56 +02:00

292 lines
9.2 KiB
Python

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 = "In-Band Bytestreams"
dependencies = set(['xep_0030', ])
xep = '0065'
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):
iq = self.xmpp.Iq(sto=streamer, stype='get')
iq['q']
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.target_thread = Proxy(sid, requester, target, self.proxy_host,
self.proxy_port, self._handle_on_recv)
self.target_thread.start()
# Wait until the proxy is connected
self.target_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 requester and the target.
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.requester_thread = Proxy(iq['q']['sid'], requester, target,
self.proxy_host, self.proxy_port,
self._handle_on_recv)
self.requester_thread.start()
# Wait until the proxy is connected
self.requester_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 send(self, msg):
""" Sends the msg to the socket.
msg : The message data.
"""
if hasattr(self, 'requester_thread'):
self.requester_thread.send(msg)
elif hasattr(self, 'target_thread'):
self.target_thread.send(msg)
def _handle_on_recv(self, data):
""" A default callback when socket are receiving data.
"""
log.debug('Received: %s' % data)
class Proxy(Thread):
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('Connected')
self.connected.set()
# Listen for data on the socket
self.listen()
def listen(self):
""" Listen for data on the socket. When receiving data, call
the callback on_recv callable.
"""
while True:
ins, out, err = select([self.s, ], [], [])
for s in ins:
data = self.recv_size(self.s)
self.on_recv(data)
def recv_size(self, the_socket):
#data length is packed into 4 bytes
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 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)
def send(self, msg):
""" Sends the data over the socket.
"""
self.s.sendall(msg)