libervia-backend/sat/plugins/plugin_xep_0231.py
2019-01-12 12:25:31 +01:00

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#!/usr/bin/env python2
# -*- coding: utf-8 -*-
# SAT plugin for Bit of Binary handling (XEP-0231)
# Copyright (C) 2009-2019 Jérôme Poisson (goffi@goffi.org)
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero 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 Affero General Public License for more details.
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
from sat.core.i18n import _
from sat.core.constants import Const as C
from sat.core import exceptions
from sat.core.log import getLogger
log = getLogger(__name__)
from sat.tools import xml_tools
from wokkel import disco, iwokkel
from zope.interface import implements
from twisted.python import failure
from twisted.words.protocols.jabber import xmlstream
from twisted.words.protocols.jabber import jid
from twisted.words.protocols.jabber import error as jabber_error
from twisted.internet import defer
from functools import partial
import base64
import time
PLUGIN_INFO = {
C.PI_NAME: "Bits of Binary",
C.PI_IMPORT_NAME: "XEP-0231",
C.PI_TYPE: "XEP",
C.PI_MODES: C.PLUG_MODE_BOTH,
C.PI_PROTOCOLS: ["XEP-0231"],
C.PI_MAIN: "XEP_0231",
C.PI_HANDLER: "yes",
C.PI_DESCRIPTION: _(
"""Implementation of bits of binary (used for small images/files)"""
),
}
NS_BOB = u"urn:xmpp:bob"
IQ_BOB_REQUEST = C.IQ_GET + '/data[@xmlns="' + NS_BOB + '"]'
class XEP_0231(object):
def __init__(self, host):
log.info(_(u"plugin Bits of Binary initialization"))
self.host = host
host.registerNamespace("bob", NS_BOB)
host.trigger.add("xhtml_post_treat", self.XHTMLTrigger)
host.bridge.addMethod(
"bobGetFile",
".plugin",
in_sign="sss",
out_sign="s",
method=self._getFile,
async=True,
)
def dumpData(self, cache, data_elt, cid):
"""save file encoded in data_elt to cache
@param cache(memory.cache.Cache): cache to use to store the data
@param data_elt(domish.Element): <data> as in XEP-0231
@param cid(unicode): content-id
@return(unicode): full path to dumped file
"""
#  FIXME: is it needed to use a separate thread?
# probably not with the little data expected with BoB
try:
max_age = int(data_elt["max-age"])
if max_age < 0:
raise ValueError
except (KeyError, ValueError):
log.warning(u"invalid max-age found")
max_age = None
with cache.cacheData(
PLUGIN_INFO[C.PI_IMPORT_NAME], cid, data_elt.getAttribute("type"), max_age
) as f:
file_path = f.name
f.write(base64.b64decode(str(data_elt)))
return file_path
def getHandler(self, client):
return XEP_0231_handler(self)
def _requestCb(self, iq_elt, cache, cid):
for data_elt in iq_elt.elements(NS_BOB, u"data"):
if data_elt.getAttribute("cid") == cid:
file_path = self.dumpData(cache, data_elt, cid)
return file_path
log.warning(
u"invalid data stanza received, requested cid was not found:\n{iq_elt}\nrequested cid: {cid}".format(
iq_elt=iq_elt, cid=cid
)
)
raise failure.Failure(exceptions.DataError("missing data"))
def _requestEb(self, failure_):
"""Log the error and continue errback chain"""
log.warning(u"Can't get requested data:\n{reason}".format(reason=failure_))
return failure_
def requestData(self, client, to_jid, cid, cache=None):
"""Request data if we don't have it in cache
@param to_jid(jid.JID): jid to request the data to
@param cid(unicode): content id
@param cache(memory.cache.Cache, None): cache to use
client.cache will be used if None
@return D(unicode): path to file with data
"""
if cache is None:
cache = client.cache
iq_elt = client.IQ("get")
iq_elt["to"] = to_jid.full()
data_elt = iq_elt.addElement((NS_BOB, "data"))
data_elt["cid"] = cid
d = iq_elt.send()
d.addCallback(self._requestCb, cache, cid)
d.addErrback(self._requestEb)
return d
def _setImgEltSrc(self, path, img_elt):
img_elt[u"src"] = u"file://{}".format(path)
def XHTMLTrigger(self, client, message_elt, body_elt, lang, treat_d):
for img_elt in xml_tools.findAll(body_elt, C.NS_XHTML, u"img"):
source = img_elt.getAttribute(u"src", "")
if source.startswith(u"cid:"):
cid = source[4:]
file_path = client.cache.getFilePath(cid)
if file_path is not None:
#  image is in cache, we change the url
img_elt[u"src"] = u"file://{}".format(file_path)
continue
else:
# image is not in cache, is it given locally?
for data_elt in message_elt.elements(NS_BOB, u"data"):
if data_elt.getAttribute("cid") == cid:
file_path = self.dumpData(client.cache, data_elt, cid)
img_elt[u"src"] = u"file://{}".format(file_path)
break
else:
# cid not found locally, we need to request it
# so we use the deferred
d = self.requestData(client, jid.JID(message_elt["from"]), cid)
d.addCallback(partial(self._setImgEltSrc, img_elt=img_elt))
treat_d.addCallback(lambda __: d)
def onComponentRequest(self, iq_elt, client):
"""cache data is retrieve from common cache for components"""
# FIXME: this is a security/privacy issue as no access check is done
# but this is mitigated by the fact that the cid must be known.
# An access check should be implemented though.
iq_elt.handled = True
data_elt = next(iq_elt.elements(NS_BOB, "data"))
try:
cid = data_elt[u"cid"]
except KeyError:
error_elt = jabber_error.StanzaError("not-acceptable").toResponse(iq_elt)
client.send(error_elt)
return
metadata = self.host.common_cache.getMetadata(cid)
if metadata is None:
error_elt = jabber_error.StanzaError("item-not-found").toResponse(iq_elt)
client.send(error_elt)
return
with open(metadata["path"]) as f:
data = f.read()
result_elt = xmlstream.toResponse(iq_elt, "result")
data_elt = result_elt.addElement((NS_BOB, "data"), content=data.encode("base64"))
data_elt[u"cid"] = cid
data_elt[u"type"] = metadata[u"mime_type"]
data_elt[u"max-age"] = unicode(int(max(0, metadata["eol"] - time.time())))
client.send(result_elt)
def _getFile(self, peer_jid_s, cid, profile):
peer_jid = jid.JID(peer_jid_s)
assert cid
client = self.host.getClient(profile)
return self.getFile(client, peer_jid, cid)
def getFile(self, client, peer_jid, cid, parent_elt=None):
"""Retrieve a file from it's content-id
@param peer_jid(jid.JID): jid of the entity offering the data
@param cid(unicode): content-id of file data
@param parent_elt(domish.Element, None): if file is not in cache,
data will be looked after in children of this elements.
None to ignore
@return D(unicode): path to cached data
"""
file_path = client.cache.getFilePath(cid)
if file_path is not None:
#  file is in cache
return defer.succeed(file_path)
else:
# file not in cache, is it given locally?
if parent_elt is not None:
for data_elt in parent_elt.elements(NS_BOB, u"data"):
if data_elt.getAttribute("cid") == cid:
return defer.succeed(self.dumpData(client.cache, data_elt, cid))
# cid not found locally, we need to request it
# so we use the deferred
return self.requestData(client, peer_jid, cid)
class XEP_0231_handler(xmlstream.XMPPHandler):
implements(iwokkel.IDisco)
def __init__(self, plugin_parent):
self.plugin_parent = plugin_parent
self.host = plugin_parent.host
def connectionInitialized(self):
if self.parent.is_component:
self.xmlstream.addObserver(
IQ_BOB_REQUEST, self.plugin_parent.onComponentRequest, client=self.parent
)
def getDiscoInfo(self, requestor, target, nodeIdentifier=""):
return [disco.DiscoFeature(NS_BOB)]
def getDiscoItems(self, requestor, target, nodeIdentifier=""):
return []