Mercurial > libervia-backend
diff libervia/backend/plugins/plugin_xep_0231.py @ 4071:4b842c1fb686
refactoring: renamed `sat` package to `libervia.backend`
author | Goffi <goffi@goffi.org> |
---|---|
date | Fri, 02 Jun 2023 11:49:51 +0200 |
parents | sat/plugins/plugin_xep_0231.py@524856bd7b19 |
children | 0d7bb4df2343 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/libervia/backend/plugins/plugin_xep_0231.py Fri Jun 02 11:49:51 2023 +0200 @@ -0,0 +1,250 @@ +#!/usr/bin/env python3 + + +# SAT plugin for Bit of Binary handling (XEP-0231) +# Copyright (C) 2009-2021 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/>. + +import base64 +import time +from pathlib import Path +from functools import partial +from zope.interface import implementer +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 wokkel import disco, iwokkel +from libervia.backend.tools import xml_tools +from libervia.backend.core.i18n import _ +from libervia.backend.core.constants import Const as C +from libervia.backend.core import exceptions +from libervia.backend.core.log import getLogger + +log = getLogger(__name__) + + +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 = "urn:xmpp:bob" +IQ_BOB_REQUEST = C.IQ_GET + '/data[@xmlns="' + NS_BOB + '"]' + + +class XEP_0231(object): + def __init__(self, host): + log.info(_("plugin Bits of Binary initialization")) + self.host = host + host.register_namespace("bob", NS_BOB) + host.trigger.add("xhtml_post_treat", self.xhtml_trigger) + host.bridge.add_method( + "bob_get_file", + ".plugin", + in_sign="sss", + out_sign="s", + method=self._get_file, + async_=True, + ) + + def dump_data(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("invalid max-age found") + max_age = None + + with cache.cache_data( + PLUGIN_INFO[C.PI_IMPORT_NAME], cid, data_elt.getAttribute("type"), max_age + ) as f: + + file_path = Path(f.name) + f.write(base64.b64decode(str(data_elt))) + + return file_path + + def get_handler(self, client): + return XEP_0231_handler(self) + + def _request_cb(self, iq_elt, cache, cid): + for data_elt in iq_elt.elements(NS_BOB, "data"): + if data_elt.getAttribute("cid") == cid: + file_path = self.dump_data(cache, data_elt, cid) + return file_path + + log.warning( + "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 _request_eb(self, failure_): + """Log the error and continue errback chain""" + log.warning("Can't get requested data:\n{reason}".format(reason=failure_)) + return failure_ + + def request_data(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._request_cb, cache, cid) + d.addErrback(self._request_eb) + return d + + def _set_img_elt_src(self, path, img_elt): + img_elt["src"] = "file://{}".format(path) + + def xhtml_trigger(self, client, message_elt, body_elt, lang, treat_d): + for img_elt in xml_tools.find_all(body_elt, C.NS_XHTML, "img"): + source = img_elt.getAttribute("src", "") + if source.startswith("cid:"): + cid = source[4:] + file_path = client.cache.get_file_path(cid) + if file_path is not None: + # image is in cache, we change the url + img_elt["src"] = "file://{}".format(file_path) + continue + else: + # image is not in cache, is it given locally? + for data_elt in message_elt.elements(NS_BOB, "data"): + if data_elt.getAttribute("cid") == cid: + file_path = self.dump_data(client.cache, data_elt, cid) + img_elt["src"] = "file://{}".format(file_path) + break + else: + # cid not found locally, we need to request it + # so we use the deferred + d = self.request_data(client, jid.JID(message_elt["from"]), cid) + d.addCallback(partial(self._set_img_elt_src, img_elt=img_elt)) + treat_d.addCallback(lambda __: d) + + def on_component_request(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["cid"] + except KeyError: + error_elt = jabber_error.StanzaError("not-acceptable").toResponse(iq_elt) + client.send(error_elt) + return + + metadata = self.host.common_cache.get_metadata(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"], 'rb') as f: + data = f.read() + + result_elt = xmlstream.toResponse(iq_elt, "result") + data_elt = result_elt.addElement( + (NS_BOB, "data"), content=base64.b64encode(data).decode()) + data_elt["cid"] = cid + data_elt["type"] = metadata["mime_type"] + data_elt["max-age"] = str(int(max(0, metadata["eol"] - time.time()))) + client.send(result_elt) + + def _get_file(self, peer_jid_s, cid, profile): + peer_jid = jid.JID(peer_jid_s) + assert cid + client = self.host.get_client(profile) + d = self.get_file(client, peer_jid, cid) + d.addCallback(lambda path: str(path)) + return d + + def get_file(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(Path): path to cached data + """ + file_path = client.cache.get_file_path(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, "data"): + if data_elt.getAttribute("cid") == cid: + return defer.succeed(self.dump_data(client.cache, data_elt, cid)) + + # cid not found locally, we need to request it + # so we use the deferred + return self.request_data(client, peer_jid, cid) + + +@implementer(iwokkel.IDisco) +class XEP_0231_handler(xmlstream.XMPPHandler): + + 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.on_component_request, client=self.parent + ) + + def getDiscoInfo(self, requestor, target, nodeIdentifier=""): + return [disco.DiscoFeature(NS_BOB)] + + def getDiscoItems(self, requestor, target, nodeIdentifier=""): + return []