""" Handling of RTP media streams according to RFC3550, RFC3605, RFC3581, RFC2833 and RFC3711, RFC3489 and RFC5245. """ __all__ = ['RTPStream'] import weakref from abc import ABCMeta, abstractmethod from application.notification import IObserver, NotificationCenter, NotificationData, ObserverWeakrefProxy from application.python import Null from threading import RLock from zope.interface import implements from sipsimple.account import BonjourAccount from sipsimple.configuration.settings import SIPSimpleSettings from sipsimple.core import RTPTransport, SIPCoreError, SIPURI from sipsimple.lookup import DNSLookup from sipsimple.streams import IMediaStream, InvalidStreamError, MediaStreamType, UnknownStreamError from sipsimple.threading import run_in_thread class ZRTPStreamOptions(object): implements(IObserver) def __init__(self, stream): self._stream = stream self.__dict__['master'] = None self.__dict__['sas'] = None self.__dict__['verified'] = False self.__dict__['peer_name'] = '' @property def sas(self): if self.master is not None: return self.master.encryption.zrtp.sas return self.__dict__['sas'] @property def verified(self): if self.master is not None: return self.master.encryption.zrtp.verified return self.__dict__['verified'] @verified.setter def verified(self, verified): if self.__dict__['verified'] == verified: return if self.sas is None: raise AttributeError('Cannot verify peer before SAS is received') if self.master is not None: self.master.encryption.zrtp.verified = verified else: rtp_transport = self._stream._rtp_transport if rtp_transport is not None: @run_in_thread('file-io') def update_verified(rtp_transport, verified): rtp_transport.set_zrtp_sas_verified(verified) notification_center = NotificationCenter() notification_center.post_notification('RTPStreamZRTPVerifiedStateChanged', sender=self._stream, data=NotificationData(verified=verified)) self.__dict__['verified'] = verified update_verified(rtp_transport, verified) @property def peer_id(self): if self.master is not None: return self.master.encryption.zrtp.peer_id rtp_transport = self._stream._rtp_transport if rtp_transport is None: return None return rtp_transport.zrtp_peer_id @property def peer_name(self): if self.master is not None: return self.master.encryption.zrtp.peer_name return self.__dict__['peer_name'] @peer_name.setter def peer_name(self, name): if self.__dict__['peer_name'] == name: return if self.master is not None: self.master.encryption.zrtp.peer_name = name else: rtp_transport = self._stream._rtp_transport if rtp_transport is not None: @run_in_thread('file-io') def update_name(rtp_transport, name): rtp_transport.zrtp_peer_name = name notification_center = NotificationCenter() notification_center.post_notification('RTPStreamZRTPPeerNameChanged', sender=self._stream, data=NotificationData(name=name)) self.__dict__['peer_name'] = name update_name(rtp_transport, name) @property def master(self): return self.__dict__['master'] @master.setter def master(self, master): old_master = self.__dict__['master'] if old_master is master: return notification_center = NotificationCenter() if old_master is not None: notification_center.remove_observer(self, sender=old_master) if master is not None: notification_center.add_observer(self, sender=master) self.__dict__['master'] = master def _enable(self, master_stream=None): rtp_transport = self._stream._rtp_transport if rtp_transport is None: return if master_stream is not None and not (master_stream.encryption.active and master_stream.encryption.type == 'ZRTP'): raise RuntimeError('Master stream must have ZRTP encryption activated') rtp_transport.set_zrtp_enabled(True, master_stream) self.master = master_stream def handle_notification(self, notification): handler = getattr(self, '_NH_%s' % notification.name, Null) handler(notification) def _NH_RTPStreamZRTPReceivedSAS(self, notification): # ZRTP begins on the audio stream, so this notification will only be processed # by the other streams self.__dict__['sas'] = notification.data.sas self.__dict__['verified'] = notification.data.verified self.__dict__['peer_name'] = notification.data.peer_name notification.center.post_notification(notification.name, sender=self._stream, data=notification.data) def _NH_RTPStreamZRTPVerifiedStateChanged(self, notification): self.__dict__['verified'] = notification.data.verified notification.center.post_notification(notification.name, sender=self._stream, data=notification.data) def _NH_RTPStreamZRTPPeerNameChanged(self, notification): self.__dict__['peer_name'] = notification.data.name notification.center.post_notification(notification.name, sender=self._stream, data=notification.data) def _NH_MediaStreamDidEnd(self, notification): self.master = None class RTPStreamEncryption(object): implements(IObserver) def __init__(self, stream): self._stream_ref = weakref.ref(stream) # Keep a weak reference before the stream is initialized to avoid a memory cycle that would delay releasing audio resources self._stream = None # We will store the actual reference once it's initialized and we're guaranteed to get MediaStreamDidEnd and do the cleanup self._rtp_transport = None self.__dict__['type'] = None self.__dict__['zrtp'] = None notification_center = NotificationCenter() notification_center.add_observer(ObserverWeakrefProxy(self), name='MediaStreamDidInitialize') notification_center.add_observer(ObserverWeakrefProxy(self), name='MediaStreamDidNotInitialize') @property def active(self): rtp_transport = self._rtp_transport if rtp_transport is None: return False if self.type == 'SRTP/SDES': return rtp_transport.srtp_active elif self.type == 'ZRTP': return rtp_transport.zrtp_active return False @property def cipher(self): rtp_transport = self._rtp_transport if rtp_transport is None: return None if self.type == 'SRTP/SDES': return rtp_transport.srtp_cipher elif self.type == 'ZRTP': return rtp_transport.zrtp_cipher return None @property def type(self): return self.__dict__['type'] @property def zrtp(self): zrtp = self.__dict__['zrtp'] if zrtp is None: raise RuntimeError('ZRTP options have not been initialized') return zrtp def handle_notification(self, notification): handler = getattr(self, '_NH_%s' % notification.name, Null) handler(notification) def _NH_MediaStreamDidInitialize(self, notification): stream = notification.sender if stream is self._stream_ref(): self._stream = stream self._rtp_transport = stream._rtp_transport notification.center.remove_observer(ObserverWeakrefProxy(self), name='MediaStreamDidInitialize') notification.center.remove_observer(ObserverWeakrefProxy(self), name='MediaStreamDidNotInitialize') notification.center.add_observer(self, sender=self._stream) notification.center.add_observer(self, sender=self._rtp_transport) encryption = stream._srtp_encryption or '' if encryption.startswith('sdes'): self.__dict__['type'] = 'SRTP/SDES' elif encryption == 'zrtp': self.__dict__['type'] = 'ZRTP' self.__dict__['zrtp'] = ZRTPStreamOptions(stream) def _NH_MediaStreamDidNotInitialize(self, notification): if notification.sender is self._stream_ref(): notification.center.remove_observer(ObserverWeakrefProxy(self), name='MediaStreamDidInitialize') notification.center.remove_observer(ObserverWeakrefProxy(self), name='MediaStreamDidNotInitialize') self._stream_ref = None self._stream = None def _NH_MediaStreamDidStart(self, notification): if self.type == 'SRTP/SDES': stream = notification.sender if self.active: notification.center.post_notification('RTPStreamDidEnableEncryption', sender=stream) else: reason = 'Not supported by remote' notification.center.post_notification('RTPStreamDidNotEnableEncryption', sender=stream, data=NotificationData(reason=reason)) def _NH_MediaStreamDidEnd(self, notification): notification.center.remove_observer(self, sender=self._stream) notification.center.remove_observer(self, sender=self._rtp_transport) self._stream = None self._stream_ref = None self._rtp_transport = None self.__dict__['type'] = None self.__dict__['zrtp'] = None def _NH_RTPTransportZRTPSecureOn(self, notification): stream = self._stream with stream._lock: if stream.state == "ENDED": return notification.center.post_notification('RTPStreamDidEnableEncryption', sender=stream) def _NH_RTPTransportZRTPSecureOff(self, notification): # We should never get here because we don't allow disabling encryption -Saul pass def _NH_RTPTransportZRTPReceivedSAS(self, notification): stream = self._stream with stream._lock: if stream.state == "ENDED": return self.zrtp.__dict__['sas'] = sas = notification.data.sas self.zrtp.__dict__['verified'] = verified = notification.data.verified self.zrtp.__dict__['peer_name'] = peer_name = notification.sender.zrtp_peer_name notification.center.post_notification('RTPStreamZRTPReceivedSAS', sender=stream, data=NotificationData(sas=sas, verified=verified, peer_name=peer_name)) def _NH_RTPTransportZRTPLog(self, notification): stream = self._stream with stream._lock: if stream.state == "ENDED": return notification.center.post_notification('RTPStreamZRTPLog', sender=stream, data=notification.data) def _NH_RTPTransportZRTPNegotiationFailed(self, notification): stream = self._stream with stream._lock: if stream.state == "ENDED": return reason = 'Negotiation failed: %s' % notification.data.reason notification.center.post_notification('RTPStreamDidNotEnableEncryption', sender=stream, data=NotificationData(reason=reason)) def _NH_RTPTransportZRTPNotSupportedByRemote(self, notification): stream = self._stream with stream._lock: if stream.state == "ENDED": return reason = 'ZRTP not supported by remote' notification.center.post_notification('RTPStreamDidNotEnableEncryption', sender=stream, data=NotificationData(reason=reason)) class RTPStreamType(ABCMeta, MediaStreamType): pass class RTPStream(object): __metaclass__ = RTPStreamType implements(IMediaStream, IObserver) type = None priority = None hold_supported = True def __init__(self): self.notification_center = NotificationCenter() self.on_hold_by_local = False self.on_hold_by_remote = False self.direction = None self.state = "NULL" self.session = None self.encryption = RTPStreamEncryption(self) self._transport = None self._hold_request = None self._ice_state = "NULL" self._lock = RLock() self._rtp_transport = None self._try_ice = False self._srtp_encryption = None self._remote_rtp_address_sdp = None self._remote_rtp_port_sdp = None self._initialized = False self._done = False self._failure_reason = None @property def codec(self): return self._transport.codec if self._transport else None @property def sample_rate(self): return self._transport.sample_rate if self._transport else None @property def statistics(self): return self._transport.statistics if self._transport else None @property def local_rtp_address(self): return self._rtp_transport.local_rtp_address if self._rtp_transport else None @property def local_rtp_port(self): return self._rtp_transport.local_rtp_port if self._rtp_transport else None @property def local_rtp_candidate(self): return self._rtp_transport.local_rtp_candidate if self._rtp_transport else None @property def remote_rtp_address(self): if self._ice_state == "IN_USE": return self._rtp_transport.remote_rtp_address if self._rtp_transport else None return self._remote_rtp_address_sdp if self._rtp_transport else None @property def remote_rtp_port(self): if self._ice_state == "IN_USE": return self._rtp_transport.remote_rtp_port if self._rtp_transport else None return self._remote_rtp_port_sdp if self._rtp_transport else None @property def remote_rtp_candidate(self): return self._rtp_transport.remote_rtp_candidate if self._rtp_transport else None @property def ice_active(self): return self._ice_state == "IN_USE" @property def on_hold(self): return self.on_hold_by_local or self.on_hold_by_remote @abstractmethod def start(self, local_sdp, remote_sdp, stream_index): raise NotImplementedError @abstractmethod def update(self, local_sdp, remote_sdp, stream_index): raise NotImplementedError @abstractmethod def validate_update(self, remote_sdp, stream_index): raise NotImplementedError @abstractmethod def deactivate(self): raise NotImplementedError @abstractmethod def end(self): raise NotImplementedError @abstractmethod def reset(self, stream_index): raise NotImplementedError def hold(self): with self._lock: if self.on_hold_by_local or self._hold_request == 'hold': return if self.state == "ESTABLISHED" and self.direction != "inactive": self._pause() self._hold_request = 'hold' def unhold(self): with self._lock: if (not self.on_hold_by_local and self._hold_request != 'hold') or self._hold_request == 'unhold': return if self.state == "ESTABLISHED" and self._hold_request == 'hold': self._resume() self._hold_request = None if self._hold_request == 'hold' else 'unhold' @classmethod def new_from_sdp(cls, session, remote_sdp, stream_index): # TODO: actually validate the SDP settings = SIPSimpleSettings() remote_stream = remote_sdp.media[stream_index] if remote_stream.media != cls.type: raise UnknownStreamError if remote_stream.transport not in ('RTP/AVP', 'RTP/SAVP'): raise InvalidStreamError("expected RTP/AVP or RTP/SAVP transport in %s stream, got %s" % (cls.type, remote_stream.transport)) local_encryption_policy = session.account.rtp.encryption.key_negotiation if session.account.rtp.encryption.enabled else None if local_encryption_policy == "sdes_mandatory" and not "crypto" in remote_stream.attributes: raise InvalidStreamError("SRTP/SDES is locally mandatory but it's not remotely enabled") if remote_stream.transport == 'RTP/SAVP' and "crypto" in remote_stream.attributes and local_encryption_policy not in ("opportunistic", "sdes_optional", "sdes_mandatory"): raise InvalidStreamError("SRTP/SDES is remotely mandatory but it's not locally enabled") account_preferred_codecs = getattr(session.account.rtp, '%s_codec_list' % cls.type) general_codecs = getattr(settings.rtp, '%s_codec_list' % cls.type) supported_codecs = account_preferred_codecs or general_codecs if not any(codec for codec in remote_stream.codec_list if codec in supported_codecs): raise InvalidStreamError("no compatible codecs found") stream = cls() stream._incoming_remote_sdp = remote_sdp stream._incoming_stream_index = stream_index return stream def initialize(self, session, direction): with self._lock: if self.state != "NULL": raise RuntimeError("%sStream.initialize() may only be called in the NULL state" % self.type.capitalize()) self.state = "INITIALIZING" self.session = session local_encryption_policy = session.account.rtp.encryption.key_negotiation if session.account.rtp.encryption.enabled else None if hasattr(self, "_incoming_remote_sdp") and hasattr(self, '_incoming_stream_index'): # ICE attributes could come at the session level or at the media level remote_stream = self._incoming_remote_sdp.media[self._incoming_stream_index] self._try_ice = self.session.account.nat_traversal.use_ice and ((remote_stream.has_ice_attributes or self._incoming_remote_sdp.has_ice_attributes) and remote_stream.has_ice_candidates) if "zrtp-hash" in remote_stream.attributes: incoming_stream_encryption = 'zrtp' elif "crypto" in remote_stream.attributes: incoming_stream_encryption = 'sdes_mandatory' if remote_stream.transport == 'RTP/SAVP' else 'sdes_optional' else: incoming_stream_encryption = None if incoming_stream_encryption is not None and local_encryption_policy == 'opportunistic': self._srtp_encryption = incoming_stream_encryption else: self._srtp_encryption = 'zrtp' if local_encryption_policy == 'opportunistic' else local_encryption_policy else: self._try_ice = self.session.account.nat_traversal.use_ice self._srtp_encryption = 'zrtp' if local_encryption_policy == 'opportunistic' else local_encryption_policy if self._try_ice: if self.session.account.nat_traversal.stun_server_list: stun_servers = list((server.host, server.port) for server in self.session.account.nat_traversal.stun_server_list) self._init_rtp_transport(stun_servers) elif not isinstance(self.session.account, BonjourAccount): dns_lookup = DNSLookup() self.notification_center.add_observer(self, sender=dns_lookup) dns_lookup.lookup_service(SIPURI(self.session.account.id.domain), "stun") else: self._init_rtp_transport() def get_local_media(self, remote_sdp=None, index=0): with self._lock: if self.state not in ("INITIALIZED", "WAIT_ICE", "ESTABLISHED"): raise RuntimeError("%sStream.get_local_media() may only be called in the INITIALIZED, WAIT_ICE or ESTABLISHED states" % self.type.capitalize()) if remote_sdp is None: # offer old_direction = self._transport.direction if old_direction is None: new_direction = "sendrecv" elif "send" in old_direction: new_direction = ("sendonly" if (self._hold_request == 'hold' or (self._hold_request is None and self.on_hold_by_local)) else "sendrecv") else: new_direction = ("inactive" if (self._hold_request == 'hold' or (self._hold_request is None and self.on_hold_by_local)) else "recvonly") else: new_direction = None return self._transport.get_local_media(remote_sdp, index, new_direction) # Notifications def handle_notification(self, notification): handler = getattr(self, '_NH_%s' % notification.name, Null) handler(notification) def _NH_DNSLookupDidFail(self, notification): self.notification_center.remove_observer(self, sender=notification.sender) with self._lock: if self.state == "ENDED": return self._init_rtp_transport() def _NH_DNSLookupDidSucceed(self, notification): self.notification_center.remove_observer(self, sender=notification.sender) with self._lock: if self.state == "ENDED": return self._init_rtp_transport(notification.data.result) def _NH_RTPTransportDidInitialize(self, notification): rtp_transport = notification.sender with self._lock: if self.state == "ENDED": self.notification_center.remove_observer(self, sender=rtp_transport) return del self._rtp_args del self._stun_servers remote_sdp = self.__dict__.pop('_incoming_remote_sdp', None) stream_index = self.__dict__.pop('_incoming_stream_index', None) try: if remote_sdp is not None: transport = self._create_transport(rtp_transport, remote_sdp=remote_sdp, stream_index=stream_index) self._save_remote_sdp_rtp_info(remote_sdp, stream_index) else: transport = self._create_transport(rtp_transport) except SIPCoreError, e: self.state = "ENDED" self.notification_center.remove_observer(self, sender=rtp_transport) self.notification_center.post_notification('MediaStreamDidNotInitialize', sender=self, data=NotificationData(reason=e.args[0])) return self._rtp_transport = rtp_transport self._transport = transport self.notification_center.add_observer(self, sender=transport) self._initialized = True self.state = "INITIALIZED" self.notification_center.post_notification('MediaStreamDidInitialize', sender=self) def _NH_RTPTransportDidFail(self, notification): self.notification_center.remove_observer(self, sender=notification.sender) with self._lock: if self.state == "ENDED": return self._try_next_rtp_transport(notification.data.reason) def _NH_RTPTransportICENegotiationStateDidChange(self, notification): with self._lock: if self._ice_state != "NULL" or self.state not in ("INITIALIZING", "INITIALIZED", "WAIT_ICE"): return self.notification_center.post_notification('RTPStreamICENegotiationStateDidChange', sender=self, data=notification.data) def _NH_RTPTransportICENegotiationDidSucceed(self, notification): with self._lock: if self.state != "WAIT_ICE": return self._ice_state = "IN_USE" self.state = 'ESTABLISHED' self.notification_center.post_notification('RTPStreamICENegotiationDidSucceed', sender=self, data=notification.data) self.notification_center.post_notification('MediaStreamDidStart', sender=self) def _NH_RTPTransportICENegotiationDidFail(self, notification): with self._lock: if self.state != "WAIT_ICE": return self._ice_state = "FAILED" self.state = 'ESTABLISHED' self.notification_center.post_notification('RTPStreamICENegotiationDidFail', sender=self, data=notification.data) self.notification_center.post_notification('MediaStreamDidStart', sender=self) # Private methods def _init_rtp_transport(self, stun_servers=None): self._rtp_args = dict() self._rtp_args["encryption"] = self._srtp_encryption self._rtp_args["use_ice"] = self._try_ice self._stun_servers = [(None, None)] if stun_servers: self._stun_servers.extend(reversed(stun_servers)) self._try_next_rtp_transport() def _try_next_rtp_transport(self, failure_reason=None): if self._stun_servers: stun_address, stun_port = self._stun_servers.pop() try: rtp_transport = RTPTransport(ice_stun_address=stun_address, ice_stun_port=stun_port, **self._rtp_args) except SIPCoreError, e: self._try_next_rtp_transport(e.args[0]) else: self.notification_center.add_observer(self, sender=rtp_transport) try: rtp_transport.set_INIT() except SIPCoreError, e: self.notification_center.remove_observer(self, sender=rtp_transport) self._try_next_rtp_transport(e.args[0]) else: self.state = "ENDED" self.notification_center.post_notification('MediaStreamDidNotInitialize', sender=self, data=NotificationData(reason=failure_reason)) def _save_remote_sdp_rtp_info(self, remote_sdp, index): connection = remote_sdp.media[index].connection or remote_sdp.connection self._remote_rtp_address_sdp = connection.address self._remote_rtp_port_sdp = remote_sdp.media[index].port @abstractmethod def _create_transport(self, rtp_transport, remote_sdp=None, stream_index=None): raise NotImplementedError @abstractmethod def _check_hold(self, direction, is_initial): raise NotImplementedError @abstractmethod def _pause(self): raise NotImplementedError @abstractmethod def _resume(self): raise NotImplementedError from sipsimple.streams.rtp import audio, video