plugin av-conferences: implement Jingle A/V conferences:

This plugin implements the Jingle A/V Conferences specification. The plugin is small as
it's mostly (only so far) about specifying/retrieving <origin> element, and disco info;
the rest is handled by other Jingle plugins.

libervia/backend/plugins/plugin_comp_pubsub/__init__.py

@@ -45,7 +45,7 @@ from libervia.backend.memory.sqla_mapping import (
     SubscriptionState,
 )
 from libervia.backend.plugins.plugin_xep_0060 import NodeMetadata, XEP_0060
-from libervia.backend.plugins.plugin_xep_0167 import NS_AV_CONFERENCES
+from libervia.backend.plugins.plugin_misc_av_conferences import NS_AV_CONFERENCES
 from libervia.backend.plugins.plugin_xep_0355 import XEP_0355, DelegationData
 from libervia.backend.plugins.plugin_xep_0356 import XEP_0356
 from libervia.backend.plugins.plugin_xep_0496 import LINK_VAR, PARENT_VAR, XEP_0496

libervia/backend/plugins/plugin_misc_av_conferences.py

@@ -0,0 +1,136 @@
+#!/usr/bin/env python3
+
+# Libervia plugin to handle Audio/Video conferences
+# Copyright (C) 2009-2026 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 twisted.words.protocols.jabber.xmlstream import XMPPHandler
+from twisted.words.xish import domish
+from tx_xmpp import disco, itx_xmpp
+from zope.interface import implementer
+
+from libervia.backend.core.constants import Const as C
+from libervia.backend.core.core_types import SatXMPPEntity
+from libervia.backend.core.i18n import _
+from libervia.backend.core.log import getLogger
+from libervia.backend.plugins.plugin_xep_0166 import XEP_0166
+
+log = getLogger(__name__)
+
+
+PLUGIN_INFO = {
+    C.PI_NAME: "Jingle A/V Conferences",
+    C.PI_IMPORT_NAME: "AV_CONFERENCES",
+    C.PI_TYPE: "MISC",
+    C.PI_MODES: C.PLUG_MODE_BOTH,
+    C.PI_PROTOCOLS: [],
+    C.PI_DEPENDENCIES: ["XEP-0166", "XEP-0167"],
+    C.PI_MAIN: "AVConferences",
+    C.PI_HANDLER: "yes",
+    C.PI_DESCRIPTION: _(
+        "Handle Audio/Video conferences (A/V calls with a large number of participants).\n"
+        "This plugin implements the Jingle Audio/Video conferences for calls with a "
+        "large number of participants."
+    ),
+}
+
+NS_AV_CONFERENCES = "urn:xmpp:jingle:av-conferences:0"
+
+
+class AVConferences:
+    namespace = NS_AV_CONFERENCES
+
+    def __init__(self, host):
+        log.info(f"plugin {PLUGIN_INFO[C.PI_NAME]!r} initialization")
+        self.host = host
+        self._j: XEP_0166 = host.plugins["XEP-0166"]
+        host.trigger.add("XEP-0167_jingle_handler", self._jingle_handler_trigger)
+
+    def get_handler(self, client):
+        return AVConferencesHandler(self)
+
+    def _jingle_handler_trigger(
+        self,
+        client: SatXMPPEntity,
+        action: str,
+        session: dict,
+        content_name: str,
+        desc_elt: domish.Element,
+    ) -> None:
+        """Store the origin of the contents.
+
+        The origin is kept in the content's application data, so that it can be exposed to
+            the frontend.
+        """
+        if action != self._j.A_CONTENT_ADD:
+            return
+        # get <origin> from the element tree, not the session state, which may be updated
+        # by a concurrent content-add before this trigger runs
+        try:
+            jingle_elt = desc_elt.parent.parent
+        except AttributeError:
+            jingle_elt = None
+        if jingle_elt is None:
+            jingle_elt = session.get("jingle_elt")
+        if jingle_elt is None:
+            return
+        assert jingle_elt.name == "jingle"
+        origin = self.parse_origin(jingle_elt)
+        if origin is None:
+            return
+        log.debug(
+            f"Content {content_name!r} of session {session['id']!r} "
+            f"({client.jid.full()}) originates from {origin!r}."
+        )
+        content_data = session["contents"].get(content_name)
+        if content_data is not None:
+            content_data["application_data"]["origin"] = origin
+
+    @staticmethod
+    def build_origin_elt(origin: str) -> domish.Element:
+        """Create an <origin> element to identify the stream origin
+
+        @param origin: entity URI of the stream origin (typically an "xmpp:" URL)
+        @return: <origin> element
+        """
+        origin_elt = domish.Element((NS_AV_CONFERENCES, "origin"))
+        origin_elt["entity"] = origin
+        return origin_elt
+
+    @staticmethod
+    def parse_origin(jingle_elt: domish.Element) -> str | None:
+        """Get the origin of the stream from a <jingle> element
+
+        @return: entity URI of the stream origin, or None
+        """
+        try:
+            origin_elt = next(jingle_elt.elements(NS_AV_CONFERENCES, "origin"))
+        except StopIteration:
+            return None
+        return origin_elt.getAttribute("entity")
+
+
+@implementer(itx_xmpp.IDisco)
+class AVConferencesHandler(XMPPHandler):
+    def __init__(self, plugin_parent):
+        self.plugin_parent = plugin_parent
+
+    def getDiscoInfo(self, requestor, target, nodeIdentifier=""):
+        return [
+            disco.DiscoFeature(NS_AV_CONFERENCES),
+        ]
+
+    def getDiscoItems(self, requestor, target, nodeIdentifier=""):
+        return []

libervia/backend/plugins/plugin_xep_0167/constants.py

@@ -24,4 +24,3 @@ NS_JINGLE_RTP_AUDIO: Final = f"{NS_JINGLE_RTP_BASE}:audio"
 NS_JINGLE_RTP_VIDEO: Final = f"{NS_JINGLE_RTP_BASE}:video"
 NS_JINGLE_RTP_ERRORS: Final = f"{NS_JINGLE_RTP_BASE}:errors:1"
 NS_JINGLE_RTP_INFO: Final = f"{NS_JINGLE_RTP_BASE}:info:1"
-NS_AV_CONFERENCES: Final = "urn:xmpp:jingle:av-conferences:0"