libervia-backend/libervia/backend/plugins/plugin_xep_0294.py
2026-03-31 12:57:17 +02:00

253 lines
9.4 KiB
Python

#!/usr/bin/env python3
# Libervia plugin
# 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 typing import Dict, List, Optional, Union
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 import exceptions
from libervia.backend.core.constants import Const as C
from libervia.backend.core.i18n import _
from libervia.backend.core.log import getLogger
log = getLogger(__name__)
NS_JINGLE_RTP_HDREXT = "urn:xmpp:jingle:apps:rtp:rtp-hdrext:0"
PLUGIN_INFO = {
C.PI_NAME: "Jingle RTP Header Extensions Negotiation",
C.PI_IMPORT_NAME: "XEP-0294",
C.PI_TYPE: "XEP",
C.PI_MODES: C.PLUG_MODE_BOTH,
C.PI_PROTOCOLS: ["XEP-0294"],
C.PI_DEPENDENCIES: ["XEP-0167"],
C.PI_RECOMMENDATIONS: [],
C.PI_MAIN: "XEP_0294",
C.PI_HANDLER: "yes",
C.PI_DESCRIPTION: _("""Jingle RTP Header Extensions Negotiation"""),
}
class XEP_0294:
def __init__(self, host):
log.info(f"plugin {PLUGIN_INFO[C.PI_NAME]!r} initialization")
host.trigger.add("XEP-0167_parse_sdp_a", self._parse_sdp_a_trigger)
host.trigger.add(
"XEP-0167_generate_sdp_content", self._generate_sdp_content_trigger
)
host.trigger.add("XEP-0167_parse_description", self._parse_description_trigger)
host.trigger.add("XEP-0167_build_description", self._build_description_trigger)
def get_handler(self, client):
return XEP_0294_handler()
def _parse_extmap(self, parts: List[str], application_data: dict) -> None:
"""Parse an individual extmap line and fill application_data accordingly"""
if "/" in parts[0]:
id_, direction = parts[0].split("/", 1)
else:
id_ = parts[0]
direction = None
uri = parts[1]
attributes = parts[2:]
if direction in (None, "sendrecv"):
senders = "both"
elif direction == "sendonly":
senders = "initiator"
elif direction == "recvonly":
senders = "responder"
elif direction == "inactive":
senders = "none"
else:
log.warning(f"invalid direction for extmap: {direction}")
senders = "sendrecv"
rtp_hdr_ext_data: Dict[str, Union[str, dict]] = {
"id": id_,
"uri": uri,
"senders": senders,
}
if attributes:
parameters = {}
for attribute in attributes:
name, *value = attribute.split("=", 1)
parameters[name] = value[0] if value else None
rtp_hdr_ext_data["parameters"] = parameters
application_data.setdefault("rtp-hdrext", {})[id_] = rtp_hdr_ext_data
def _parse_sdp_a_trigger(
self,
attribute: str,
parts: List[str],
call_data: dict,
metadata: dict,
media_type: str,
application_data: Optional[dict],
transport_data: dict,
) -> None:
"""Parse "extmap" and "extmap-allow-mixed" attributes"""
if attribute == "extmap":
if application_data is None:
call_data.setdefault("_extmaps", []).append(parts)
else:
self._parse_extmap(parts, application_data)
elif attribute == "extmap-allow-mixed":
if application_data is None:
call_data["_extmap-allow-mixed"] = True
else:
application_data["extmap-allow-mixed"] = True
elif (
application_data is not None
and "_extmaps" in call_data
and "rtp-hdrext" not in application_data
):
extmaps = call_data.pop("_extmaps")
for parts in extmaps:
self._parse_extmap(parts, application_data)
elif (
application_data is not None
and "_extmap-allow-mixed" in call_data
and "extmap-allow-mixed" not in application_data
):
value = call_data.pop("_extmap-allow-mixed")
application_data["extmap-allow-mixed"] = value
def _generate_sdp_content_trigger(
self,
session: dict,
local: bool,
idx: int,
content_data: dict,
sdp_lines: List[str],
application_data: dict,
app_data_key: str,
media_data: dict,
media: str,
) -> None:
"""Generate "extmap" and "extmap-allow-mixed" attributes"""
rtp_hdrext_dict = media_data.get("rtp-hdrext", {})
for id_, ext_data in rtp_hdrext_dict.items():
senders = ext_data.get("senders")
if senders in (None, "both"):
direction = "sendrecv"
elif senders == "initiator":
direction = "sendonly"
elif senders == "responder":
direction = "recvonly"
elif senders == "none":
direction = "inactive"
else:
raise exceptions.InternalError(
f"Invalid senders value for extmap: {ext_data.get('senders')}"
)
parameters_str = ""
if "parameters" in ext_data:
parameters_str = " " + " ".join(
f"{k}={v}" if v is not None else f"{k}"
for k, v in ext_data["parameters"].items()
)
sdp_lines.append(
f"a=extmap:{id_}/{direction} {ext_data['uri']}{parameters_str}"
)
if media_data.get("extmap-allow-mixed", False):
sdp_lines.append("a=extmap-allow-mixed")
def _parse_description_trigger(
self, desc_elt: domish.Element, media_data: dict
) -> None:
"""Parse the <rtp-hdrext> and <extmap-allow-mixed> elements"""
for rtp_hdrext_elt in desc_elt.elements(NS_JINGLE_RTP_HDREXT, "rtp-hdrext"):
id_ = rtp_hdrext_elt["id"]
uri = rtp_hdrext_elt["uri"]
senders = rtp_hdrext_elt.getAttribute("senders", "both")
# FIXME: workaround for Movim bug https://github.com/movim/movim/issues/1212
if senders in ("sendonly", "recvonly", "sendrecv", "inactive"):
log.warning("Movim bug workaround for wrong extmap value")
if senders == "sendonly":
senders = "initiator"
elif senders == "recvonly":
senders = "responder"
elif senders == "sendrecv":
senders = "both"
else:
senders = "none"
media_data.setdefault("rtp-hdrext", {})[id_] = {
"id": id_,
"uri": uri,
"senders": senders,
}
parameters = {}
for param_elt in rtp_hdrext_elt.elements(NS_JINGLE_RTP_HDREXT, "parameter"):
try:
parameters[param_elt["name"]] = param_elt.getAttribute("value")
except KeyError:
log.warning(f"invalid parameters (missing name): {param_elt.toXml()}")
if parameters:
media_data["rtp-hdrext"][id_]["parameters"] = parameters
try:
next(desc_elt.elements(NS_JINGLE_RTP_HDREXT, "extmap-allow-mixed"))
except StopIteration:
pass
else:
media_data["extmap-allow-mixed"] = True
def _build_description_trigger(
self, desc_elt: domish.Element, media_data: dict, session: dict
) -> None:
"""Build the <rtp-hdrext> and <extmap-allow-mixed> elements if possible"""
for id_, hdrext_data in media_data.get("rtp-hdrext", {}).items():
rtp_hdrext_elt = desc_elt.addElement((NS_JINGLE_RTP_HDREXT, "rtp-hdrext"))
rtp_hdrext_elt["id"] = id_
rtp_hdrext_elt["uri"] = hdrext_data["uri"]
senders = hdrext_data.get("senders", "both")
if senders != "both":
# we must not set "both" senders otherwise calls will fail with Movim due
# to https://github.com/movim/movim/issues/1213
rtp_hdrext_elt["senders"] = senders
for name, value in hdrext_data.get("parameters", {}).items():
param_elt = rtp_hdrext_elt.addElement((NS_JINGLE_RTP_HDREXT, "parameter"))
param_elt["name"] = name
if value is not None:
param_elt["value"] = value
if media_data.get("extmap-allow-mixed", False):
desc_elt.addElement((NS_JINGLE_RTP_HDREXT, "extmap-allow-mixed"))
@implementer(itx_xmpp.IDisco)
class XEP_0294_handler(XMPPHandler):
def getDiscoInfo(self, requestor, target, nodeIdentifier=""):
return [disco.DiscoFeature(NS_JINGLE_RTP_HDREXT)]
def getDiscoItems(self, requestor, target, nodeIdentifier=""):
return []