handle senders modification via content-modify

Dino uses this to enable/disable video when a video content is already present

src/main/java/eu/siacs/conversations/xmpp/jingle/JingleConnectionManager.java

@@ -251,7 +251,9 @@ public class JingleConnectionManager extends AbstractConnectionManager {
         final Element error = response.addChild("error");
         error.setAttribute("type", conditionType);
         error.addChild(condition, "urn:ietf:params:xml:ns:xmpp-stanzas");
+        if (jingleCondition != null) {
             error.addChild(jingleCondition, Namespace.JINGLE_ERRORS);
+        }
         account.getXmppConnection().sendIqPacket(response, null);
     }
 

src/main/java/eu/siacs/conversations/xmpp/jingle/JingleRtpConnection.java

@@ -14,8 +14,11 @@ import com.google.common.base.Throwables;
 import com.google.common.collect.Collections2;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableMultimap;
 import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Iterables;
 import com.google.common.collect.Maps;
+import com.google.common.collect.Multimap;
 import com.google.common.collect.Sets;
 import com.google.common.primitives.Ints;
 import com.google.common.util.concurrent.FutureCallback;
@@ -551,15 +554,17 @@ public class JingleRtpConnection extends AbstractJingleConnection
     }
 
     private void receiveContentModify(final JinglePacket jinglePacket) {
+        // TODO check session accepted
         final Map<String, Content.Senders> modification =
                 Maps.transformEntries(
                         jinglePacket.getJingleContents(), (key, value) -> value.getSenders());
-        respondOk(jinglePacket);
+        final boolean isInitiator = isInitiator();
         final RtpContentMap currentOutgoing = this.outgoingContentAdd;
+        final RtpContentMap remoteContentMap = this.getRemoteContentMap();
         final Set<String> currentOutgoingMediaIds = currentOutgoing == null ? Collections.emptySet() : currentOutgoing.contents.keySet();
         Log.d(Config.LOGTAG, "receiveContentModification(" + modification + ")");
         if (currentOutgoing != null && currentOutgoingMediaIds.containsAll(modification.keySet())) {
-            final boolean isInitiator = isInitiator();
+            respondOk(jinglePacket);
             final RtpContentMap modifiedContentMap;
             try {
                 modifiedContentMap = currentOutgoing.modifiedSendersChecked(isInitiator, modification);
@@ -570,16 +575,70 @@ public class JingleRtpConnection extends AbstractJingleConnection
             }
             this.outgoingContentAdd = modifiedContentMap;
             Log.d(Config.LOGTAG, id.account.getJid().asBareJid()+": processed content-modification for pending content-add");
-        } else {
+        } else if (remoteContentMap != null && remoteContentMap.contents.keySet().containsAll(modification.keySet())) {
+            respondOk(jinglePacket);
+            final RtpContentMap modifiedRemoteContentMap;
+            try {
+                modifiedRemoteContentMap = remoteContentMap.modifiedSendersChecked(isInitiator, modification);
+            } catch (final IllegalArgumentException e) {
                 webRTCWrapper.close();
-            sendSessionTerminate(
+                sendSessionTerminate(Reason.FAILED_APPLICATION, e.getMessage());
-                    Reason.FAILED_APPLICATION,
+                return;
-                    String.format(
-                            "%s only supports %s as a means to modify a not yet accepted %s",
-                            BuildConfig.APP_NAME,
-                            JinglePacket.Action.CONTENT_MODIFY,
-                            JinglePacket.Action.CONTENT_ADD));
             }
+            final SessionDescription offer;
+            try {
+                offer = SessionDescription.of(modifiedRemoteContentMap, !isInitiator());
+            } catch (final IllegalArgumentException | NullPointerException e) {
+                Log.d(Config.LOGTAG, id.getAccount().getJid().asBareJid() + ": unable convert offer from content-modify to SDP", e);
+                webRTCWrapper.close();
+                sendSessionTerminate(Reason.FAILED_APPLICATION, e.getMessage());
+                return;
+            }
+            Log.d(Config.LOGTAG, id.account.getJid().asBareJid()+": auto accepting content-modification");
+            this.autoAcceptContentModify(modifiedRemoteContentMap, offer);
+        } else {
+            Log.d(Config.LOGTAG,"received unsupported content modification "+modification);
+            respondWithItemNotFound(jinglePacket);
+        }
+    }
+
+    private void autoAcceptContentModify(final RtpContentMap modifiedRemoteContentMap, final SessionDescription offer) {
+        this.setRemoteContentMap(modifiedRemoteContentMap);
+        final org.webrtc.SessionDescription sdp =
+                new org.webrtc.SessionDescription(
+                        org.webrtc.SessionDescription.Type.OFFER, offer.toString());
+        try {
+            this.webRTCWrapper.setRemoteDescription(sdp).get();
+            // auto accept is only done when we already have tracks
+            final SessionDescription answer = setLocalSessionDescription();
+            final RtpContentMap rtpContentMap = RtpContentMap.of(answer, isInitiator());
+            modifyLocalContentMap(rtpContentMap);
+            // we do not need to send an answer but do we have to resend the candidates currently in SDP?
+            //resendCandidatesFromSdp(answer);
+            webRTCWrapper.setIsReadyToReceiveIceCandidates(true);
+        } catch (final Exception e) {
+            Log.d(Config.LOGTAG, "unable to accept content add", Throwables.getRootCause(e));
+            webRTCWrapper.close();
+            sendSessionTerminate(Reason.FAILED_APPLICATION);
+        }
+    }
+
+    private void resendCandidatesFromSdp(final SessionDescription answer) {
+        final ImmutableMultimap.Builder<String, IceUdpTransportInfo.Candidate> candidateBuilder = new ImmutableMultimap.Builder<>();
+        for(final SessionDescription.Media media : answer.media) {
+            final String mid = Iterables.getFirst(media.attributes.get("mid"), null);
+            if (Strings.isNullOrEmpty(mid)) {
+                continue;
+            }
+            for(final String sdpCandidate : media.attributes.get("candidate")) {
+                final IceUdpTransportInfo.Candidate candidate = IceUdpTransportInfo.Candidate.fromSdpAttributeValue(sdpCandidate, null);
+                if (candidate != null) {
+                    candidateBuilder.put(mid,candidate);
+                }
+            }
+        }
+        final ImmutableMultimap<String, IceUdpTransportInfo.Candidate> candidates = candidateBuilder.build();
+        sendTransportInfo(candidates);
     }
 
     private void receiveContentReject(final JinglePacket jinglePacket) {
@@ -1942,6 +2001,11 @@ public class JingleRtpConnection extends AbstractJingleConnection
         send(jinglePacket);
     }
 
+    private void sendTransportInfo(final Multimap<String, IceUdpTransportInfo.Candidate> candidates) {
+        // TODO send all candidates in one transport-info
+    }
+
+
     private void send(final JinglePacket jinglePacket) {
         jinglePacket.setTo(id.with);
         xmppConnectionService.sendIqPacket(id.account, jinglePacket, this::handleIqResponse);
@@ -2028,6 +2092,10 @@ public class JingleRtpConnection extends AbstractJingleConnection
         respondWithJingleError(jinglePacket, "out-of-order", "unexpected-request", "wait");
     }
 
+    private void respondWithItemNotFound(final JinglePacket jinglePacket) {
+        respondWithJingleError(jinglePacket, null, "item-not-found", "cancel");
+    }
+
     void respondWithJingleError(
             final IqPacket original,
             String jingleCondition,

src/main/java/eu/siacs/conversations/xmpp/jingle/stanzas/IceUdpTransportInfo.java

@@ -202,8 +202,16 @@ public class IceUdpTransportInfo extends GenericTransportInfo {
         public static Candidate fromSdpAttribute(final String attribute, String currentUfrag) {
             final String[] pair = attribute.split(":", 2);
             if (pair.length == 2 && "candidate".equals(pair[0])) {
-                final String[] segments = pair[1].split(" ");
+                return fromSdpAttributeValue(pair[1], currentUfrag);
-                if (segments.length >= 6) {
+            }
+            return null;
+        }
+
+        public static Candidate fromSdpAttributeValue(final String value, final String currentUfrag) {
+            final String[] segments = value.split(" ");
+            if (segments.length < 6) {
+                return null;
+            }
             final String id = UUID.randomUUID().toString();
             final String foundation = segments[0];
             final String component = segments[1];
@@ -216,7 +224,7 @@ public class IceUdpTransportInfo extends GenericTransportInfo {
                 additional.put(segments[i], segments[i + 1]);
             }
             final String ufrag = additional.get("ufrag");
-                    if (ufrag != null && !ufrag.equals(currentUfrag)) {
+            if (currentUfrag != null && ufrag != null && !ufrag.equals(currentUfrag)) {
                 return null;
             }
             final Candidate candidate = new Candidate();
@@ -233,9 +241,6 @@ public class IceUdpTransportInfo extends GenericTransportInfo {
             candidate.setAttribute("type", additional.get("typ"));
             return candidate;
         }
-            }
-            return null;
-        }
 
         public int getComponent() {
             return getAttributeAsInt("component");