feat: Configurable limit for the number of data channels.

Author: bgrozev

jvb/src/main/java/org/jitsi/videobridge/datachannel/DataChannelStack.java

@@ -18,6 +18,7 @@
 
 import org.jitsi.utils.logging2.*;
 import org.jitsi.videobridge.datachannel.protocol.*;
+import org.jitsi.videobridge.sctp.*;
 
 import java.nio.*;
 import java.util.*;
@@ -60,6 +61,12 @@ public void onIncomingDataChannelPacket(ByteBuffer data, int sid, int ppid)
         if (message instanceof OpenChannelMessage)
         {
             logger.debug("Received data channel open message");
+            if (dataChannels.size() >= SctpConfig.config.getMaxChannels())
+            {
+                logger.warn("Data channel limit exceeded.");
+                return;
+            }
+
             OpenChannelMessage openChannelMessage = (OpenChannelMessage)message;
             // Remote side wants to open a channel
             DataChannel dataChannel = new RemotelyOpenedDataChannel(

jvb/src/main/kotlin/org/jitsi/videobridge/sctp/SctpConfig.kt

@@ -24,6 +24,8 @@ class SctpConfig private constructor() {
     val enabled: Boolean by config { "videobridge.sctp.enabled".from(JitsiConfig.newConfig) }
     fun enabled() = enabled
 
+    val maxChannels: Int by config { "videobridge.sctp.max-channels".from(JitsiConfig.newConfig) }
+
     companion object {
         @JvmField
         val config = SctpConfig()

jvb/src/main/resources/reference.conf

@@ -246,6 +246,9 @@ videobridge {
   sctp {
     // Whether SCTP data channels are enabled.
     enabled = true
+
+    // Maximum number of data channels per connection
+    max-channels = 1
   }
   stats {
     // The interval at which stats are gathered.