package eu.siacs.conversations.xmpp.jingle; import android.util.Log; import com.google.common.collect.ImmutableList; import com.google.common.collect.ImmutableMap; import org.webrtc.IceCandidate; import org.webrtc.PeerConnection; import java.util.ArrayDeque; import java.util.Arrays; import java.util.Collection; import java.util.Collections; import java.util.List; import java.util.Map; import eu.siacs.conversations.Config; import eu.siacs.conversations.xml.Element; import eu.siacs.conversations.xml.Namespace; import eu.siacs.conversations.xmpp.jingle.stanzas.Group; import eu.siacs.conversations.xmpp.jingle.stanzas.IceUdpTransportInfo; import eu.siacs.conversations.xmpp.jingle.stanzas.JinglePacket; import eu.siacs.conversations.xmpp.jingle.stanzas.Reason; import eu.siacs.conversations.xmpp.stanzas.IqPacket; import eu.siacs.conversations.xmpp.stanzas.MessagePacket; import rocks.xmpp.addr.Jid; public class JingleRtpConnection extends AbstractJingleConnection implements WebRTCWrapper.EventCallback { private static final Map> VALID_TRANSITIONS; static { final ImmutableMap.Builder> transitionBuilder = new ImmutableMap.Builder<>(); transitionBuilder.put(State.NULL, ImmutableList.of(State.PROPOSED, State.SESSION_INITIALIZED)); transitionBuilder.put(State.PROPOSED, ImmutableList.of(State.ACCEPTED, State.PROCEED, State.REJECTED, State.RETRACTED)); transitionBuilder.put(State.PROCEED, ImmutableList.of(State.SESSION_INITIALIZED_PRE_APPROVED, State.TERMINATED_SUCCESS)); transitionBuilder.put(State.SESSION_INITIALIZED, ImmutableList.of(State.SESSION_ACCEPTED, State.TERMINATED_CANCEL_OR_TIMEOUT, State.TERMINATED_DECLINED_OR_BUSY)); transitionBuilder.put(State.SESSION_INITIALIZED_PRE_APPROVED, ImmutableList.of(State.SESSION_ACCEPTED, State.TERMINATED_CANCEL_OR_TIMEOUT, State.TERMINATED_DECLINED_OR_BUSY)); transitionBuilder.put(State.SESSION_ACCEPTED, ImmutableList.of(State.TERMINATED_SUCCESS, State.TERMINATED_CONNECTIVITY_ERROR)); VALID_TRANSITIONS = transitionBuilder.build(); } private final WebRTCWrapper webRTCWrapper = new WebRTCWrapper(this); private final ArrayDeque pendingIceCandidates = new ArrayDeque<>(); private State state = State.NULL; private RtpContentMap initiatorRtpContentMap; private RtpContentMap responderRtpContentMap; public JingleRtpConnection(JingleConnectionManager jingleConnectionManager, Id id, Jid initiator) { super(jingleConnectionManager, id, initiator); } private static State reasonToState(Reason reason) { switch (reason) { case SUCCESS: return State.TERMINATED_SUCCESS; case DECLINE: case BUSY: return State.TERMINATED_DECLINED_OR_BUSY; case CANCEL: case TIMEOUT: return State.TERMINATED_CANCEL_OR_TIMEOUT; default: return State.TERMINATED_CONNECTIVITY_ERROR; } } @Override void deliverPacket(final JinglePacket jinglePacket) { Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": packet delivered to JingleRtpConnection"); switch (jinglePacket.getAction()) { case SESSION_INITIATE: receiveSessionInitiate(jinglePacket); break; case TRANSPORT_INFO: receiveTransportInfo(jinglePacket); break; case SESSION_ACCEPT: receiveSessionAccept(jinglePacket); break; case SESSION_TERMINATE: receiveSessionTerminate(jinglePacket); break; default: Log.d(Config.LOGTAG, String.format("%s: received unhandled jingle action %s", id.account.getJid().asBareJid(), jinglePacket.getAction())); break; } } private void receiveSessionTerminate(final JinglePacket jinglePacket) { final Reason reason = jinglePacket.getReason(); final State previous = this.state; Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": received session terminate reason=" + reason + " while in state " + previous); webRTCWrapper.close(); transitionOrThrow(reasonToState(reason)); if (previous == State.PROPOSED || previous == State.SESSION_INITIALIZED) { xmppConnectionService.getNotificationService().cancelIncomingCallNotification(); } jingleConnectionManager.finishConnection(this); } private void receiveTransportInfo(final JinglePacket jinglePacket) { if (isInState(State.SESSION_INITIALIZED, State.SESSION_INITIALIZED_PRE_APPROVED, State.SESSION_ACCEPTED)) { final RtpContentMap contentMap; try { contentMap = RtpContentMap.of(jinglePacket); } catch (IllegalArgumentException | NullPointerException e) { Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": improperly formatted contents", e); return; } final RtpContentMap rtpContentMap = isInitiator() ? this.responderRtpContentMap : this.initiatorRtpContentMap; final Group originalGroup = rtpContentMap != null ? rtpContentMap.group : null; final List identificationTags = originalGroup == null ? Collections.emptyList() : originalGroup.getIdentificationTags(); if (identificationTags.size() == 0) { Log.w(Config.LOGTAG, id.account.getJid().asBareJid() + ": no identification tags found in initial offer. we won't be able to calculate mLineIndices"); } for (final Map.Entry content : contentMap.contents.entrySet()) { final String ufrag = content.getValue().transport.getAttribute("ufrag"); for (final IceUdpTransportInfo.Candidate candidate : content.getValue().transport.getCandidates()) { final String sdp = candidate.toSdpAttribute(ufrag); final String sdpMid = content.getKey(); final int mLineIndex = identificationTags.indexOf(sdpMid); final IceCandidate iceCandidate = new IceCandidate(sdpMid, mLineIndex, sdp); if (isInState(State.SESSION_ACCEPTED)) { Log.d(Config.LOGTAG, "received candidate: " + iceCandidate); this.webRTCWrapper.addIceCandidate(iceCandidate); } else { this.pendingIceCandidates.offer(iceCandidate); Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": put ICE candidate on backlog"); } } } } else { Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": received transport info while in state=" + this.state); } } private void receiveSessionInitiate(final JinglePacket jinglePacket) { if (isInitiator()) { Log.d(Config.LOGTAG, String.format("%s: received session-initiate even though we were initiating", id.account.getJid().asBareJid())); //TODO respond with out-of-order return; } final RtpContentMap contentMap; try { contentMap = RtpContentMap.of(jinglePacket); contentMap.requireContentDescriptions(); } catch (IllegalArgumentException | IllegalStateException | NullPointerException e) { Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": improperly formatted contents", e); return; } Log.d(Config.LOGTAG, "processing session-init with " + contentMap.contents.size() + " contents"); final State target; if (this.state == State.PROCEED) { target = State.SESSION_INITIALIZED_PRE_APPROVED; } else { target = State.SESSION_INITIALIZED; } if (transition(target)) { this.initiatorRtpContentMap = contentMap; if (target == State.SESSION_INITIALIZED_PRE_APPROVED) { Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": automatically accepting session-initiate"); sendSessionAccept(); } else { Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": received not pre-approved session-initiate. start ringing"); startRinging(); } } else { Log.d(Config.LOGTAG, String.format("%s: received session-initiate while in state %s", id.account.getJid().asBareJid(), state)); } } private void receiveSessionAccept(final JinglePacket jinglePacket) { if (!isInitiator()) { Log.d(Config.LOGTAG, String.format("%s: received session-accept even though we were responding", id.account.getJid().asBareJid())); //TODO respond with out-of-order return; } final RtpContentMap contentMap; try { contentMap = RtpContentMap.of(jinglePacket); contentMap.requireContentDescriptions(); } catch (IllegalArgumentException | IllegalStateException | NullPointerException e) { Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": improperly formatted contents", e); return; } Log.d(Config.LOGTAG, "processing session-accept with " + contentMap.contents.size() + " contents"); if (transition(State.SESSION_ACCEPTED)) { receiveSessionAccept(contentMap); } else { Log.d(Config.LOGTAG, String.format("%s: received session-accept while in state %s", id.account.getJid().asBareJid(), state)); //TODO out-of-order } } private void receiveSessionAccept(final RtpContentMap contentMap) { this.responderRtpContentMap = contentMap; org.webrtc.SessionDescription answer = new org.webrtc.SessionDescription( org.webrtc.SessionDescription.Type.ANSWER, SessionDescription.of(contentMap).toString() ); try { this.webRTCWrapper.setRemoteDescription(answer).get(); } catch (Exception e) { Log.d(Config.LOGTAG, "unable to receive session accept", e); } } private void sendSessionAccept() { final RtpContentMap rtpContentMap = this.initiatorRtpContentMap; if (rtpContentMap == null) { throw new IllegalStateException("initiator RTP Content Map has not been set"); } final SessionDescription offer; try { offer = SessionDescription.of(rtpContentMap); } catch (final IllegalArgumentException e) { Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": unable to process offer", e); //TODO terminate session with application error return; } sendSessionAccept(offer); } private void sendSessionAccept(SessionDescription offer) { discoverIceServers(iceServers -> { setupWebRTC(iceServers); final org.webrtc.SessionDescription sdp = new org.webrtc.SessionDescription( org.webrtc.SessionDescription.Type.OFFER, offer.toString() ); try { this.webRTCWrapper.setRemoteDescription(sdp).get(); addIceCandidatesFromBlackLog(); org.webrtc.SessionDescription webRTCSessionDescription = this.webRTCWrapper.createAnswer().get(); final SessionDescription sessionDescription = SessionDescription.parse(webRTCSessionDescription.description); final RtpContentMap respondingRtpContentMap = RtpContentMap.of(sessionDescription); sendSessionAccept(respondingRtpContentMap); this.webRTCWrapper.setLocalDescription(webRTCSessionDescription); } catch (Exception e) { Log.d(Config.LOGTAG, "unable to send session accept", e); } }); } private void addIceCandidatesFromBlackLog() { while (!this.pendingIceCandidates.isEmpty()) { final IceCandidate iceCandidate = this.pendingIceCandidates.poll(); this.webRTCWrapper.addIceCandidate(iceCandidate); Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": added ICE candidate from back log " + iceCandidate); } } private void sendSessionAccept(final RtpContentMap rtpContentMap) { this.responderRtpContentMap = rtpContentMap; this.transitionOrThrow(State.SESSION_ACCEPTED); final JinglePacket sessionAccept = rtpContentMap.toJinglePacket(JinglePacket.Action.SESSION_ACCEPT, id.sessionId); Log.d(Config.LOGTAG, sessionAccept.toString()); send(sessionAccept); } void deliveryMessage(final Jid from, final Element message) { Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": delivered message to JingleRtpConnection " + message); switch (message.getName()) { case "propose": receivePropose(from, message); break; case "proceed": receiveProceed(from, message); break; case "retract": receiveRetract(from, message); break; case "reject": receiveReject(from, message); break; case "accept": receiveAccept(from, message); break; default: break; } } private void receiveAccept(Jid from, Element message) { final boolean originatedFromMyself = from.asBareJid().equals(id.account.getJid().asBareJid()); if (originatedFromMyself) { if (transition(State.ACCEPTED)) { this.xmppConnectionService.getNotificationService().cancelIncomingCallNotification(); this.jingleConnectionManager.finishConnection(this); } else { Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": unable to transition to accept because already in state=" + this.state); } } else { Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": ignoring 'accept' from " + from); } } private void receiveReject(Jid from, Element message) { final boolean originatedFromMyself = from.asBareJid().equals(id.account.getJid().asBareJid()); //reject from another one of my clients if (originatedFromMyself) { if (transition(State.REJECTED)) { this.xmppConnectionService.getNotificationService().cancelIncomingCallNotification(); this.jingleConnectionManager.finishConnection(this); } else { Log.d(Config.LOGTAG, "not able to transition into REJECTED because already in " + this.state); } } else { Log.d(Config.LOGTAG, id.account.getJid() + ": ignoring reject from " + from + " for session with " + id.with); } } private void receivePropose(final Jid from, final Element propose) { final boolean originatedFromMyself = from.asBareJid().equals(id.account.getJid().asBareJid()); //TODO we can use initiator logic here if (originatedFromMyself) { Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": saw proposal from mysql. ignoring"); } else if (transition(State.PROPOSED)) { startRinging(); } else { Log.d(Config.LOGTAG, id.account.getJid() + ": ignoring session proposal because already in " + state); } } private void startRinging() { Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": received call from " + id.with + ". start ringing"); xmppConnectionService.getNotificationService().showIncomingCallNotification(id); } private void receiveProceed(final Jid from, final Element proceed) { if (from.equals(id.with)) { if (isInitiator()) { if (transition(State.PROCEED)) { this.sendSessionInitiate(State.SESSION_INITIALIZED_PRE_APPROVED); } else { Log.d(Config.LOGTAG, String.format("%s: ignoring proceed because already in %s", id.account.getJid().asBareJid(), this.state)); } } else { Log.d(Config.LOGTAG, String.format("%s: ignoring proceed because we were not initializing", id.account.getJid().asBareJid())); } } else if (from.asBareJid().equals(id.account.getJid().asBareJid())) { if (transition(State.ACCEPTED)) { Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": moved session with " + id.with + " into state accepted after received carbon copied procced"); this.xmppConnectionService.getNotificationService().cancelIncomingCallNotification(); this.jingleConnectionManager.finishConnection(this); } } else { //TODO a carbon copied proceed from another client of mine has the same logic as `accept` Log.d(Config.LOGTAG, String.format("%s: ignoring proceed from %s. was expected from %s", id.account.getJid().asBareJid(), from, id.with)); } } private void receiveRetract(final Jid from, final Element retract) { if (from.equals(id.with)) { if (transition(State.RETRACTED)) { xmppConnectionService.getNotificationService().cancelIncomingCallNotification(); Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": session with " + id.with + " has been retracted"); //TODO create missed call notification/message jingleConnectionManager.finishConnection(this); } else { Log.d(Config.LOGTAG, "ignoring retract because already in " + this.state); } } else { Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": received retract from " + from + ". expected retract from" + id.with + ". ignoring"); } } private void sendSessionInitiate(final State targetState) { Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": prepare session-initiate"); discoverIceServers(iceServers -> { setupWebRTC(iceServers); try { org.webrtc.SessionDescription webRTCSessionDescription = this.webRTCWrapper.createOffer().get(); final SessionDescription sessionDescription = SessionDescription.parse(webRTCSessionDescription.description); Log.d(Config.LOGTAG, "description: " + webRTCSessionDescription.description); final RtpContentMap rtpContentMap = RtpContentMap.of(sessionDescription); sendSessionInitiate(rtpContentMap, targetState); this.webRTCWrapper.setLocalDescription(webRTCSessionDescription).get(); } catch (Exception e) { Log.d(Config.LOGTAG, "unable to sendSessionInitiate", e); } }); } private void sendSessionInitiate(RtpContentMap rtpContentMap, final State targetState) { this.initiatorRtpContentMap = rtpContentMap; this.transitionOrThrow(targetState); final JinglePacket sessionInitiate = rtpContentMap.toJinglePacket(JinglePacket.Action.SESSION_INITIATE, id.sessionId); Log.d(Config.LOGTAG, sessionInitiate.toString()); send(sessionInitiate); } private void sendSessionTerminate(final Reason reason) { final State target = reasonToState(reason); transitionOrThrow(target); final JinglePacket jinglePacket = new JinglePacket(JinglePacket.Action.SESSION_TERMINATE, id.sessionId); jinglePacket.setReason(reason); send(jinglePacket); Log.d(Config.LOGTAG, jinglePacket.toString()); jingleConnectionManager.finishConnection(this); } private void sendTransportInfo(final String contentName, IceUdpTransportInfo.Candidate candidate) { final RtpContentMap transportInfo; try { final RtpContentMap rtpContentMap = isInitiator() ? this.initiatorRtpContentMap : this.responderRtpContentMap; transportInfo = rtpContentMap.transportInfo(contentName, candidate); } catch (Exception e) { Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": unable to prepare transport-info from candidate for content=" + contentName); return; } final JinglePacket jinglePacket = transportInfo.toJinglePacket(JinglePacket.Action.TRANSPORT_INFO, id.sessionId); Log.d(Config.LOGTAG, jinglePacket.toString()); send(jinglePacket); } private void send(final JinglePacket jinglePacket) { jinglePacket.setTo(id.with); //TODO track errors xmppConnectionService.sendIqPacket(id.account, jinglePacket, null); } public RtpEndUserState getEndUserState() { switch (this.state) { case PROPOSED: case SESSION_INITIALIZED: if (isInitiator()) { return RtpEndUserState.RINGING; } else { return RtpEndUserState.INCOMING_CALL; } case PROCEED: if (isInitiator()) { return RtpEndUserState.RINGING; } else { return RtpEndUserState.ACCEPTING_CALL; } case SESSION_INITIALIZED_PRE_APPROVED: if (isInitiator()) { return RtpEndUserState.RINGING; } else { return RtpEndUserState.CONNECTING; } case SESSION_ACCEPTED: final PeerConnection.PeerConnectionState state = webRTCWrapper.getState(); if (state == PeerConnection.PeerConnectionState.CONNECTED) { return RtpEndUserState.CONNECTED; } else if (state == PeerConnection.PeerConnectionState.NEW || state == PeerConnection.PeerConnectionState.CONNECTING) { return RtpEndUserState.CONNECTING; } else if (state == PeerConnection.PeerConnectionState.CLOSED) { return RtpEndUserState.ENDING_CALL; } else if (state == PeerConnection.PeerConnectionState.FAILED) { return RtpEndUserState.CONNECTIVITY_ERROR; } else { return RtpEndUserState.ENDING_CALL; } case REJECTED: case TERMINATED_DECLINED_OR_BUSY: if (isInitiator()) { return RtpEndUserState.DECLINED_OR_BUSY; } else { return RtpEndUserState.ENDED; } case TERMINATED_SUCCESS: case ACCEPTED: case RETRACTED: case TERMINATED_CANCEL_OR_TIMEOUT: return RtpEndUserState.ENDED; case TERMINATED_CONNECTIVITY_ERROR: return RtpEndUserState.CONNECTIVITY_ERROR; } throw new IllegalStateException(String.format("%s has no equivalent EndUserState", this.state)); } public void acceptCall() { switch (this.state) { case PROPOSED: acceptCallFromProposed(); break; case SESSION_INITIALIZED: acceptCallFromSessionInitialized(); break; default: throw new IllegalStateException("Can not accept call from " + this.state); } } public void rejectCall() { switch (this.state) { case PROPOSED: rejectCallFromProposed(); break; case SESSION_INITIALIZED: rejectCallFromSessionInitiate(); break; default: throw new IllegalStateException("Can not reject call from " + this.state); } } public void endCall() { if (isInState(State.PROCEED)) { Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": ending call while in state PROCEED just means ending the connection"); webRTCWrapper.close(); jingleConnectionManager.finishConnection(this); transitionOrThrow(State.TERMINATED_SUCCESS); //arguably this wasn't success; but not a real failure either return; } if (isInitiator() && isInState(State.SESSION_INITIALIZED, State.SESSION_INITIALIZED_PRE_APPROVED)) { webRTCWrapper.close(); sendSessionTerminate(Reason.CANCEL); return; } if (isInState(State.SESSION_INITIALIZED, State.SESSION_INITIALIZED_PRE_APPROVED, State.SESSION_ACCEPTED)) { webRTCWrapper.close(); sendSessionTerminate(Reason.SUCCESS); return; } throw new IllegalStateException("called 'endCall' while in state " + this.state); } private void setupWebRTC(final List iceServers) { this.webRTCWrapper.setup(this.xmppConnectionService); this.webRTCWrapper.initializePeerConnection(iceServers); } private void acceptCallFromProposed() { transitionOrThrow(State.PROCEED); xmppConnectionService.getNotificationService().cancelIncomingCallNotification(); this.sendJingleMessage("accept", id.account.getJid().asBareJid()); this.sendJingleMessage("proceed"); } private void rejectCallFromProposed() { transitionOrThrow(State.REJECTED); xmppConnectionService.getNotificationService().cancelIncomingCallNotification(); this.sendJingleMessage("reject"); jingleConnectionManager.finishConnection(this); } private void rejectCallFromSessionInitiate() { webRTCWrapper.close(); sendSessionTerminate(Reason.DECLINE); xmppConnectionService.getNotificationService().cancelIncomingCallNotification(); } private void sendJingleMessage(final String action) { sendJingleMessage(action, id.with); } private void sendJingleMessage(final String action, final Jid to) { final MessagePacket messagePacket = new MessagePacket(); messagePacket.setType(MessagePacket.TYPE_CHAT); //we want to carbon copy those messagePacket.setTo(to); messagePacket.addChild(action, Namespace.JINGLE_MESSAGE).setAttribute("id", id.sessionId); Log.d(Config.LOGTAG, messagePacket.toString()); xmppConnectionService.sendMessagePacket(id.account, messagePacket); } private void acceptCallFromSessionInitialized() { xmppConnectionService.getNotificationService().cancelIncomingCallNotification(); sendSessionAccept(); } private synchronized boolean isInState(State... state) { return Arrays.asList(state).contains(this.state); } private synchronized boolean transition(final State target) { final Collection validTransitions = VALID_TRANSITIONS.get(this.state); if (validTransitions != null && validTransitions.contains(target)) { this.state = target; Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": transitioned into " + target); updateEndUserState(); return true; } else { return false; } } public void transitionOrThrow(final State target) { if (!transition(target)) { throw new IllegalStateException(String.format("Unable to transition from %s to %s", this.state, target)); } } @Override public void onIceCandidate(final IceCandidate iceCandidate) { final IceUdpTransportInfo.Candidate candidate = IceUdpTransportInfo.Candidate.fromSdpAttribute(iceCandidate.sdp); Log.d(Config.LOGTAG, "sending candidate: " + iceCandidate.toString()); sendTransportInfo(iceCandidate.sdpMid, candidate); } @Override public void onConnectionChange(final PeerConnection.PeerConnectionState newState) { Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": PeerConnectionState changed to " + newState); updateEndUserState(); if (newState == PeerConnection.PeerConnectionState.FAILED) { //TODO guard this in isState(initiated,initated_approved,accepted) otherwise it might fire too late sendSessionTerminate(Reason.CONNECTIVITY_ERROR); } } private void updateEndUserState() { xmppConnectionService.notifyJingleRtpConnectionUpdate(id.account, id.with, id.sessionId, getEndUserState()); } private void discoverIceServers(final OnIceServersDiscovered onIceServersDiscovered) { if (id.account.getXmppConnection().getFeatures().extendedServiceDiscovery()) { final IqPacket request = new IqPacket(IqPacket.TYPE.GET); request.setTo(Jid.of(id.account.getJid().getDomain())); request.addChild("services", Namespace.EXTERNAL_SERVICE_DISCOVERY); xmppConnectionService.sendIqPacket(id.account, request, (account, response) -> { ImmutableList.Builder listBuilder = new ImmutableList.Builder<>(); if (response.getType() == IqPacket.TYPE.RESULT) { final Element services = response.findChild("services", Namespace.EXTERNAL_SERVICE_DISCOVERY); final List children = services == null ? Collections.emptyList() : services.getChildren(); for (final Element child : children) { if ("service".equals(child.getName())) { final String type = child.getAttribute("type"); final String host = child.getAttribute("host"); final String port = child.getAttribute("port"); final String transport = child.getAttribute("transport"); final String username = child.getAttribute("username"); final String password = child.getAttribute("password"); if (Arrays.asList("stun", "type").contains(type) && host != null && port != null && "udp".equals(transport)) { PeerConnection.IceServer.Builder iceServerBuilder = PeerConnection.IceServer.builder(String.format("%s:%s:%s", type, host, port)); if (username != null && password != null) { iceServerBuilder.setUsername(username); iceServerBuilder.setPassword(password); } final PeerConnection.IceServer iceServer = iceServerBuilder.createIceServer(); Log.d(Config.LOGTAG, id.account.getJid().asBareJid() + ": discovered ICE Server: " + iceServer); listBuilder.add(iceServer); } } } } List iceServers = listBuilder.build(); if (iceServers.size() == 0) { Log.w(Config.LOGTAG, id.account.getJid().asBareJid() + ": no ICE server found " + response); } onIceServersDiscovered.onIceServersDiscovered(iceServers); }); } else { Log.w(Config.LOGTAG, id.account.getJid().asBareJid() + ": has no external service discovery"); onIceServersDiscovered.onIceServersDiscovered(Collections.emptyList()); } } private interface OnIceServersDiscovered { void onIceServersDiscovered(List iceServers); } }