From bd52a5e6c12237e1ab4ceaf0d5933f3e5109800e Mon Sep 17 00:00:00 2001
From: Lance Stout <lancestout@gmail.com>
Date: Thu, 2 Feb 2012 18:27:23 +0100
Subject: [PATCH] Initial, mostly working XEP-0047 plugin.

This is inspired by the version from macdiesel and tomstrummer, but
their version was heavily linked with XEP-0096 and focused solely
on file transfer. This version is a more generic implementation.
---
 setup.py                               |   1 +
 sleekxmpp/plugins/xep_0047/__init__.py |  13 +++
 sleekxmpp/plugins/xep_0047/ibb.py      | 141 +++++++++++++++++++++++++
 sleekxmpp/plugins/xep_0047/stanza.py   |  63 +++++++++++
 sleekxmpp/plugins/xep_0047/stream.py   | 137 ++++++++++++++++++++++++
 5 files changed, 355 insertions(+)
 create mode 100644 sleekxmpp/plugins/xep_0047/__init__.py
 create mode 100644 sleekxmpp/plugins/xep_0047/ibb.py
 create mode 100644 sleekxmpp/plugins/xep_0047/stanza.py
 create mode 100644 sleekxmpp/plugins/xep_0047/stream.py

diff --git a/setup.py b/setup.py
index 9bcadc90..dbdc943b 100755
--- a/setup.py
+++ b/setup.py
@@ -59,6 +59,7 @@ packages     = [ 'sleekxmpp',
                  'sleekxmpp/plugins/xep_0009/stanza',
                  'sleekxmpp/plugins/xep_0030',
                  'sleekxmpp/plugins/xep_0030/stanza',
+                 'sleekxmpp/plugins/xep_0047',
                  'sleekxmpp/plugins/xep_0050',
                  'sleekxmpp/plugins/xep_0059',
                  'sleekxmpp/plugins/xep_0060',
diff --git a/sleekxmpp/plugins/xep_0047/__init__.py b/sleekxmpp/plugins/xep_0047/__init__.py
new file mode 100644
index 00000000..5a6487cc
--- /dev/null
+++ b/sleekxmpp/plugins/xep_0047/__init__.py
@@ -0,0 +1,13 @@
+"""
+    SleekXMPP: The Sleek XMPP Library
+    Copyright (C) 2012 Nathanael C. Fritz, Lance J.T. Stout
+    This file is part of SleekXMPP.
+
+    See the file LICENSE for copying permission.
+"""
+
+from sleekxmpp.plugins.xep_0047 import stanza
+from sleekxmpp.plugins.xep_0047.stanza import Open, Close, Data
+from sleekxmpp.plugins.xep_0047.stream import IBBytestream
+from sleekxmpp.plugins.xep_0047.ibb import xep_0047
+
diff --git a/sleekxmpp/plugins/xep_0047/ibb.py b/sleekxmpp/plugins/xep_0047/ibb.py
new file mode 100644
index 00000000..c4f46e2f
--- /dev/null
+++ b/sleekxmpp/plugins/xep_0047/ibb.py
@@ -0,0 +1,141 @@
+import uuid
+import logging
+import threading
+
+from sleekxmpp import Message, Iq
+from sleekxmpp.exceptions import XMPPError, IqError, IqTimeout
+from sleekxmpp.xmlstream.handler import Callback
+from sleekxmpp.xmlstream.matcher import StanzaPath
+from sleekxmpp.xmlstream import register_stanza_plugin
+from sleekxmpp.plugins.base import base_plugin
+from sleekxmpp.plugins.xep_0047 import stanza, Open, Close, Data, IBBytestream
+
+
+log = logging.getLogger(__name__)
+
+
+class xep_0047(base_plugin):
+
+    def plugin_init(self):
+        self.xep = '0047'
+        self.description = 'In-band Bytestreams'
+        self.stanza = stanza
+
+        self.streams = {}
+        self.pending_streams = {}
+        self.pending_close_streams = {}
+        self._stream_lock = threading.Lock()
+
+        self.max_block_size = self.config.get('max_block_size', 8192)
+        self.window_size = self.config.get('window_size', 1)
+        self.auto_accept = self.config.get('auto_accept', True)
+        self.accept_stream = self.config.get('accept_stream', None)
+
+        register_stanza_plugin(Iq, Open)
+        register_stanza_plugin(Iq, Close)
+        register_stanza_plugin(Iq, Data)
+
+        self.xmpp.register_handler(Callback(
+            'IBB Open',
+            StanzaPath('iq@type=set/ibb_open'),
+            self._handle_open_request))
+
+        self.xmpp.register_handler(Callback(
+            'IBB Close',
+            StanzaPath('iq@type=set/ibb_close'),
+            self._handle_close))
+
+        self.xmpp.register_handler(Callback(
+            'IBB Data',
+            StanzaPath('iq@type=set/ibb_data'),
+            self._handle_data))
+
+    def post_init(self):
+        self.xmpp['xep_0030'].add_feature('http://jabber.org/protocol/ibb')
+
+    def _accept_stream(self, iq):
+        if self.accept_stream is not None:
+            return self.accept_stream(iq)
+        if self.auto_accept:
+            if iq['ibb_open']['block_size'] <= self.max_block_size:
+                return True
+        return False
+
+    def open_stream(self, jid, block_size=4096, sid=None, window=1,
+                    ifrom=None, block=True, timeout=None, callback=None):
+        if not block and callback is not None:
+            callback = lambda resp: self._handle_opened_stream(resp, callback)
+
+        if sid is None:
+            sid = str(uuid.uuid4())
+
+        iq = self.xmpp.Iq()
+        iq['type'] = 'set'
+        iq['to'] = jid
+        iq['from'] = ifrom
+        iq['ibb_open']['block_size'] = block_size
+        iq['ibb_open']['sid'] = sid
+        iq['ibb_open']['stanza'] = 'iq'
+
+        stream = IBBytestream(self.xmpp, sid, size, 
+                              iq['to'], iq['from'], window)
+        
+        with self._stream_lock:
+            self.pending_streams[iq['id']] = stream
+                                                          
+        resp = iq.send(block=block, timeout=timeout, callback=callback)
+        if block:
+            self._handle_opened_stream(resp)
+            return stream
+
+    def _handle_opened_stream(self, iq, callback=None):
+        if iq['type'] == 'result':
+            with self._stream_lock:
+                stream = self.pending_streams[iq['id']]
+                stream.sender = iq['to']
+                stream.receiver = iq['from']
+                stream.stream_started.set()
+                self.streams[stream.sid] = stream
+                self.xmpp.event('ibb_stream_start', stream)
+
+        if callback is not None:
+            callback(iq)
+
+        with self._stream_lock:
+            if iq['id'] in self.pending_streams:
+                del self.pending_streams[iq['id']]
+
+    def _handle_open_request(self, iq):
+        sid = iq['ibb_open']['sid']
+        size = iq['ibb_open']['block_size']
+        if not self._accept_stream(iq):
+            raise XMPPError('not-acceptable')
+
+        if size > self.max_block_size:
+            raise XMPPError('resource-constraint')
+
+        stream = IBBytestream(self.xmpp, sid, size, 
+                              iq['from'], iq['to'],
+                              self.window_size)
+        stream.stream_started.set()
+        self.streams[sid] = stream
+        iq.reply()
+        iq.send()
+
+        self.xmpp.event('ibb_stream_start', stream)
+
+    def _handle_data(self, iq):
+        sid = iq['ibb_data']['sid']
+        stream = self.streams.get(sid, None)
+        if stream is not None and iq['from'] != stream.sender:
+            stream._recv_data(iq)
+        else:
+            raise XMPPError('item-not-found')
+
+    def _handle_close(self, iq):
+        sid = iq['ibb_close']['sid']
+        stream = self.streams.get(sid, None)
+        if stream is not None and iq['from'] != stream.sender:
+            stream._closed(iq)
+        else:
+            raise XMPPError('item-not-found')
diff --git a/sleekxmpp/plugins/xep_0047/stanza.py b/sleekxmpp/plugins/xep_0047/stanza.py
new file mode 100644
index 00000000..e3b55511
--- /dev/null
+++ b/sleekxmpp/plugins/xep_0047/stanza.py
@@ -0,0 +1,63 @@
+import re
+import base64
+
+from sleekxmpp.exceptions import XMPPError
+from sleekxmpp.xmlstream import register_stanza_plugin, ET, ElementBase
+from sleekxmpp.thirdparty.suelta.util import bytes
+
+
+VALID_B64 = re.compile(r'[A-Za-z0-9\+\/]*=*')
+
+
+def to_b64(data):
+    return bytes(base64.b64encode(bytes(data))).decode('utf-8')
+
+def from_b64(data):
+    return bytes(base64.b64decode(bytes(data))).decode('utf-8')
+
+
+class Open(ElementBase):
+    name = 'open'
+    namespace = 'http://jabber.org/protocol/ibb'
+    plugin_attrib = 'ibb_open'
+    interfaces = set(('block_size', 'sid', 'stanza'))
+
+    def get_block_size(self):
+        return int(self._get_attr('block-size'))
+
+    def set_block_size(self, value):
+        self._set_attr('block-size', str(value))
+
+    def del_block_size(self):
+        self._del_attr('block-size')
+
+
+class Data(ElementBase):
+    name = 'data'
+    namespace = 'http://jabber.org/protocol/ibb'
+    plugin_attrib = 'ibb_data'
+    interfaces = set(('seq', 'sid', 'data'))
+    sub_interfaces = set(['data'])
+
+    def get_seq(self):
+        return int(self._get_attr('seq', '0'))
+
+    def set_seq(self, value):
+        self._set_attr('seq', str(value))
+
+    def get_data(self):
+        b64_data = self._get_sub_text('data', '')
+        if VALID_B64.match(b64_data).group() == b64_data:
+            return from_b64(b64_data)
+        else:
+            raise XMPPError('not-acceptable')
+
+    def set_data(self, value):
+        self._set_sub_text('data', to_b64(value))
+
+
+class Close(ElementBase):
+    name = 'close'
+    namespace = 'http://jabber.org/protocol/ibb'
+    plugin_attrib = 'ibb_close'
+    interfaces = set(['sid'])
diff --git a/sleekxmpp/plugins/xep_0047/stream.py b/sleekxmpp/plugins/xep_0047/stream.py
new file mode 100644
index 00000000..73c34425
--- /dev/null
+++ b/sleekxmpp/plugins/xep_0047/stream.py
@@ -0,0 +1,137 @@
+import socket
+import threading
+import logging
+try:
+    import queue
+except ImportError:
+    import Queue as queue
+
+from sleekxmpp.exceptions import XMPPError
+
+
+log = logging.getLogger(__name__)
+
+
+class IBBytestream(object):
+
+    def __init__(self, xmpp, sid, block_size, to, ifrom, window_size=1):
+        self.xmpp = xmpp
+        self.sid = sid
+        self.block_size = block_size
+        self.window_size = window_size
+
+        self.receiver = to
+        self.sender = ifrom
+
+        self.send_seq = -1
+        self.recv_seq = -1
+
+        self._send_seq_lock = threading.Lock()
+        self._recv_seq_lock = threading.Lock()
+        
+        self.stream_started = threading.Event()
+        self.stream_in_closed = threading.Event()
+        self.stream_out_closed = threading.Event()
+
+        self.recv_queue = queue.Queue()
+
+        self.send_window = threading.BoundedSemaphore(value=self.window_size)
+        self.window_ids = set()
+        self.window_empty = threading.Event()
+        self.window_empty.set()
+
+    def send(self, data):
+        if not self.stream_started.is_set() or \
+               self.stream_out_closed.is_set():
+            raise socket.error
+        data = data[0:self.block_size]
+        self.send_window.acquire()
+        with self._send_seq_lock:
+            self.send_seq = (self.send_seq + 1) % 65535
+            seq = self.send_seq
+        iq = self.xmpp.Iq()
+        iq['type'] = 'set'
+        iq['to'] = self.receiver
+        iq['from'] = self.sender
+        iq['ibb_data']['sid'] = self.sid
+        iq['ibb_data']['seq'] = seq
+        iq['ibb_data']['data'] = data 
+        self.window_empty.clear()
+        self.window_ids.add(iq['id'])
+        iq.send(block=False, callback=self._recv_ack)
+        return len(data)
+
+    def sendall(self, data):
+        sent_len = 0
+        while sent_len < len(data):
+            sent_len += self.send(data[sent_len:])
+
+    def _recv_ack(self, iq):
+        self.window_ids.remove(iq['id'])
+        if not self.window_ids:
+            self.window_empty.set()
+        self.send_window.release()
+        if iq['type'] == 'error':
+            self.close()
+
+    def _recv_data(self, iq):
+        with self._recv_seq_lock:
+            new_seq = iq['ibb_data']['seq']
+            if new_seq != (self.recv_seq + 1) % 65535:
+                self.close()
+                raise XMPPError('unexpected-request')
+            self.recv_seq = new_seq
+
+        data = iq['ibb_data']['data']
+        if len(data) > self.block_size:
+            self.close()
+            raise XMPPError('not-acceptable')
+
+        self.recv_queue.put(data)
+        self.xmpp.event('ibb_stream_data', {'stream': self, 'data': data})
+        iq.reply()
+        iq.send()
+
+    def recv(self, *args, **kwargs):
+        return self.read(block=True)
+
+    def read(self, block=True, timeout=None, **kwargs):
+        if not self.stream_started.is_set() or \
+               self.stream_in_closed.is_set():
+            raise socket.error
+        if timeout is not None:
+            block = True
+        try:
+            return self.recv_queue.get(block, timeout)
+        except:
+            return None
+
+    def close(self):
+        iq = self.xmpp.Iq()
+        iq['type'] = 'set'
+        iq['to'] = self.receiver
+        iq['from'] = self.sender
+        iq['ibb_close']['sid'] = self.sid
+        self.stream_out_closed.set()
+        iq.send(block=False, 
+                callback=lambda x: self.stream_in_closed.set())
+        self.xmpp.event('ibb_stream_end', self)
+
+    def _closed(self, iq):
+        self.stream_in_closed.set()
+        self.stream_out_closed.set()
+        while not self.window_empty.is_set():
+            log.info('waiting for send window to empty')
+            self.window_empty.wait(timeout=1)
+        iq.reply()
+        iq.send()
+        self.xmpp.event('ibb_stream_end', self)
+
+    def makefile(self, *args, **kwargs):
+        return self
+
+    def connect(*args, **kwargs):
+        return None
+
+    def shutdown(self, *args, **kwargs):
+        return None