Fix null references (#853)

* fix: Add a null check when accessing chatRoom.

* ref: Simplify code.

* fix: Mark getChatRoom as nullable.

* fix: Add thread safe null checks around jingleSession.

* fix: Fix more nullable references.

src/main/java/org/jitsi/jicofo/conference/JitsiMeetConference.java

@@ -68,7 +68,7 @@ public interface JitsiMeetConference
      * Returns <tt>ChatRoom2</tt> instance for the MUC this instance is
      * currently in or <tt>null</tt> if it isn't in any.
      */
-    ChatRoom getChatRoom();
+    @Nullable ChatRoom getChatRoom();
 
     default JibriRecorder getJibriRecorder()
     {

src/main/java/org/jitsi/jicofo/conference/JitsiMeetConferenceImpl.java

@@ -445,7 +445,8 @@ private void joinTheRoom()
     {
         logger.info("Joining " + roomName);
 
-        chatRoom = getClientXmppProvider().findOrCreateRoom(roomName);
+        ChatRoom chatRoom = getClientXmppProvider().findOrCreateRoom(roomName);
+        this.chatRoom = chatRoom;
         chatRoom.addListener(chatRoomListener);
 
         AuthenticationAuthority authenticationAuthority = jicofoServices.getAuthenticationAuthority();
@@ -465,6 +466,7 @@ else if (ConferenceConfig.config.enableAutoOwner())
                 JigasiConfig.config.xmppConnectionName()
             ),
             this,
+            chatRoom,
             jicofoServices.getXmppServices().getJigasiDetector(),
             logger);
 
@@ -827,9 +829,9 @@ private void terminateParticipant(
 
         synchronized (participantLock)
         {
-            if (participant.isSessionEstablished())
+            JingleSession jingleSession = participant.getJingleSession();
+            if (jingleSession != null)
             {
-                JingleSession jingleSession = participant.getJingleSession();
 
                 jingle.terminateSession(jingleSession, reason, message, sendSessionTerminate);
 
@@ -1720,6 +1722,7 @@ public void onInviteFailed(ParticipantInviteRunnable channelAllocator)
      * {@inheritDoc}
      */
     @Override
+    @Nullable
     public ChatRoom getChatRoom()
     {
         return chatRoom;

src/main/java/org/jitsi/jicofo/conference/Participant.java

@@ -418,15 +418,6 @@ public ConferenceSourceMap getSources()
         return conference == null ? new ConferenceSourceMap() : conference.getSourcesForParticipant(this);
     }
 
-    /**
-     * @return {@code true} if the Jingle session with this participant has
-     * been established.
-     */
-    public boolean isSessionEstablished()
-    {
-        return jingleSession != null;
-    }
-
     /**
      * Add a set of remote sources, which are to be signaled to the remote side. The sources may be signaled
      * immediately, or queued to be signaled later.
@@ -440,7 +431,8 @@ public void addRemoteSources(ConferenceSourceMap sources)
             sources = sources.copy().stripByMediaType(getSupportedMediaTypes());
         }
 
-        if (!isSessionEstablished())
+        JingleSession jingleSession = getJingleSession();
+        if (jingleSession == null)
         {
             logger.debug("No Jingle session yet, queueing source-add.");
             remoteSourcesQueue.sourceAdd(sources);
@@ -467,7 +459,7 @@ public void addRemoteSources(ConferenceSourceMap sources)
             }
             jingle.sendAddSourceIQ(
                     sources,
-                    getJingleSession(),
+                    jingleSession,
                     ConferenceConfig.config.getUseJsonEncodedSources() && supportsJsonEncodedSources());
         }
     }
@@ -527,7 +519,8 @@ public void removeRemoteSources(ConferenceSourceMap sources)
             sources = sources.copy().stripByMediaType(getSupportedMediaTypes());
         }
 
-        if (!isSessionEstablished())
+        JingleSession jingleSession = getJingleSession();
+        if (jingleSession == null)
         {
             logger.debug("No Jingle session yet, queueing source-remove.");
             remoteSourcesQueue.sourceRemove(sources);
@@ -554,7 +547,7 @@ public void removeRemoteSources(ConferenceSourceMap sources)
             }
             jingle.sendRemoveSourceIQ(
                     sources,
-                    getJingleSession(),
+                    jingleSession,
                     ConferenceConfig.config.getUseJsonEncodedSources() && supportsJsonEncodedSources());
         }
     }
@@ -571,9 +564,10 @@ public void sendQueuedRemoteSources()
             return;
         }
 
-        if (!isSessionEstablished())
+        JingleSession jingleSession = getJingleSession();
+        if (jingleSession == null)
         {
-            logger.warn("Can not singal remote sources, Jingle session not established.");
+            logger.warn("Can not signal remote sources, Jingle session not established.");
             return;
         }
 

src/main/java/org/jitsi/jicofo/jigasi/TranscriberManager.java

@@ -93,6 +93,7 @@ public class TranscriberManager
      */
     public TranscriberManager(@NotNull XmppProvider xmppProvider,
                               @NotNull JitsiMeetConferenceImpl conference,
+                              @NotNull ChatRoom chatRoom,
                               JigasiDetector jigasiDetector,
                               @NotNull Logger parentLogger)
     {
@@ -101,7 +102,7 @@ public TranscriberManager(@NotNull XmppProvider xmppProvider,
         this.connection = xmppProvider.getXmppConnection();
 
         this.conference = conference;
-        this.chatRoom = conference.getChatRoom();
+        this.chatRoom = chatRoom;
         chatRoom.addListener(chatRoomListener);
         this.jigasiDetector = jigasiDetector;
     }

src/main/kotlin/org/jitsi/jicofo/xmpp/AvModerationHandler.kt

@@ -68,16 +68,17 @@ class AvModerationHandler(
                 if (incomingJson["type"] == "av_moderation") {
                     val conferenceJid = JidCreate.entityBareFrom(incomingJson["room"]?.toString())
 
-                    val conference = conferenceStore.getConference(conferenceJid) ?: return@execute Unit.also {
-                        logger.warn("Not processing message for not existing conference conferenceJid=$conferenceJid")
-                    }
+                    val conference = conferenceStore.getConference(conferenceJid)
+                        ?: throw IllegalStateException("Conference $conferenceJid does not exist.")
+                    val chatRoom = conference.chatRoom
+                        ?: throw IllegalStateException("Conference has no associated chatRoom.")
 
                     val enabled = incomingJson["enabled"] as Boolean?
 
                     if (enabled != null) {
                         val mediaType = MediaType.parseString(incomingJson["mediaType"] as String)
-                        val oldEnabledValue = conference.chatRoom.isAvModerationEnabled(mediaType)
-                        conference.chatRoom.setAvModerationEnabled(mediaType, enabled)
+                        val oldEnabledValue = chatRoom.isAvModerationEnabled(mediaType)
+                        chatRoom.setAvModerationEnabled(mediaType, enabled)
                         if (oldEnabledValue != enabled && enabled) {
                             logger.info(
                                 "Moderation had been enabled for conferenceJid=$conferenceJid, by=${
@@ -88,14 +89,13 @@ class AvModerationHandler(
                             conference.muteAllParticipants(mediaType)
                         }
                     } else {
-                        val lists = incomingJson["whitelists"]?.let { parseAsMapOfStringToListOfString(it) }
-                        if (lists != null) {
-                            conference.chatRoom.updateAvModerationWhitelists(lists)
+                        incomingJson["whitelists"]?.let {
+                            chatRoom.updateAvModerationWhitelists(parseAsMapOfStringToListOfString(it))
                         }
                     }
                 }
             } catch (e: Exception) {
-                logger.warn("Cannot parse json for av_moderation coming from ${stanza.from}", e)
+                logger.warn("Failed to process av_moderation request from ${stanza.from}", e)
             }
         }
     }

src/main/kotlin/org/jitsi/jicofo/xmpp/ConferenceIqHandler.kt

@@ -109,8 +109,6 @@ class ConferenceIqHandler(
      * which should be returned to the user
      */
     private fun processExtensions(query: ConferenceIq, response: ConferenceIq?, roomExists: Boolean): IQ? {
-        val peerJid = query.from
-        var identity: String? = null
         val room = query.room
         val isBreakoutRoom = breakoutAddress != null && room.domain == breakoutAddress
 
@@ -120,27 +118,20 @@ class ConferenceIqHandler(
             val authErrorOrResponse = authAuthority.processAuthentication(query, response)
 
             // Checks if authentication module wants to cancel further
-            // processing and eventually returns it's response
+            // processing and eventually returns its response
             if (authErrorOrResponse != null) {
                 return authErrorOrResponse
             }
             // Only authenticated users are allowed to create new rooms
             if (!roomExists) {
-                // If a breakout room exists and all members had left the main room, skip
+                // If an associated breakout room exists and all members have left the main room, skip
                 // authentication for the main room so users can go back to it.
-                var breakoutRoomExists: Boolean = false
-                for (conference in focusManager.getConferences()) {
-                    if (conference.chatRoom.isBreakoutRoom && room.toString() == conference.chatRoom.mainRoom) {
-                        breakoutRoomExists = true
-                        break
-                    }
+                val breakoutRoomExists = focusManager.conferences.any { conference ->
+                    conference.chatRoom?.let { it.isBreakoutRoom && room.toString() == it.mainRoom } ?: false
                 }
-                if (!breakoutRoomExists) {
-                    identity = authAuthority.getUserIdentity(peerJid)
-                    if (identity == null) {
-                        // Error not authorized
-                        return ErrorFactory.createNotAuthorizedError(query, "not authorized user domain")
-                    }
+                if (!breakoutRoomExists && authAuthority.getUserIdentity(query.from) == null) {
+                    // Error not authorized
+                    return ErrorFactory.createNotAuthorizedError(query, "not authorized user domain")
                 }
             }
         }