Control inbound message byte limits with a dynamic configuration flag

service/src/main/java/org/whispersystems/textsecuregcm/configuration/dynamic/DynamicConfiguration.java

@@ -63,6 +63,10 @@ public class DynamicConfiguration {
   @Valid
   DynamicDeliveryLatencyConfiguration deliveryLatency = new DynamicDeliveryLatencyConfiguration(Collections.emptyMap());
 
+  @JsonProperty
+  @Valid
+  DynamicInboundMessageByteLimitConfiguration inboundMessageByteLimit = new DynamicInboundMessageByteLimitConfiguration(true);
+
   public Optional<DynamicExperimentEnrollmentConfiguration> getExperimentEnrollmentConfiguration(
       final String experimentName) {
     return Optional.ofNullable(experiments.get(experimentName));
@@ -112,4 +116,8 @@ public class DynamicConfiguration {
   public DynamicDeliveryLatencyConfiguration getDeliveryLatencyConfiguration() {
     return deliveryLatency;
   }
+
+  public DynamicInboundMessageByteLimitConfiguration getInboundMessageByteLimitConfiguration() {
+    return inboundMessageByteLimit;
+  }
 }

service/src/main/java/org/whispersystems/textsecuregcm/configuration/dynamic/DynamicInboundMessageByteLimitConfiguration.java

@@ -0,0 +1,9 @@
+/*
+ * Copyright 2023 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.whispersystems.textsecuregcm.configuration.dynamic;
+
+public record DynamicInboundMessageByteLimitConfiguration(boolean enforceInboundLimit) {
+}

service/src/main/java/org/whispersystems/textsecuregcm/controllers/MessageController.java

@@ -226,7 +226,13 @@ public class MessageController {
       totalContentLength += contentLength;
     }
 
-    rateLimiters.getInboundMessageBytes().validate(destinationUuid, totalContentLength);
+    try {
+      rateLimiters.getInboundMessageBytes().validate(destinationUuid, totalContentLength);
+    } catch (final RateLimitExceededException e) {
+      if (dynamicConfigurationManager.getConfiguration().getInboundMessageByteLimitConfiguration().enforceInboundLimit()) {
+        throw e;
+      }
+    }
 
     try {
       boolean isSyncMessage = source.isPresent() && source.get().getAccount().isIdentifiedBy(destinationUuid);

service/src/test/java/org/whispersystems/textsecuregcm/controllers/MessageControllerTest.java

@@ -77,6 +77,7 @@ import org.whispersystems.textsecuregcm.auth.DisabledPermittedAuthenticatedAccou
 import org.whispersystems.textsecuregcm.auth.OptionalAccess;
 import org.whispersystems.textsecuregcm.configuration.dynamic.DynamicConfiguration;
 import org.whispersystems.textsecuregcm.configuration.dynamic.DynamicDeliveryLatencyConfiguration;
+import org.whispersystems.textsecuregcm.configuration.dynamic.DynamicInboundMessageByteLimitConfiguration;
 import org.whispersystems.textsecuregcm.entities.ECSignedPreKey;
 import org.whispersystems.textsecuregcm.entities.IncomingMessage;
 import org.whispersystems.textsecuregcm.entities.IncomingMessageList;
@@ -199,8 +200,14 @@ class MessageControllerTest {
     final DynamicDeliveryLatencyConfiguration deliveryLatencyConfiguration = mock(DynamicDeliveryLatencyConfiguration.class);
     when(deliveryLatencyConfiguration.instrumentedVersions()).thenReturn(Collections.emptyMap());
 
+    final DynamicInboundMessageByteLimitConfiguration inboundMessageByteLimitConfiguration =
+        mock(DynamicInboundMessageByteLimitConfiguration.class);
+
+    when(inboundMessageByteLimitConfiguration.enforceInboundLimit()).thenReturn(false);
+
     final DynamicConfiguration dynamicConfiguration = mock(DynamicConfiguration.class);
     when(dynamicConfiguration.getDeliveryLatencyConfiguration()).thenReturn(deliveryLatencyConfiguration);
+    when(dynamicConfiguration.getInboundMessageByteLimitConfiguration()).thenReturn(inboundMessageByteLimitConfiguration);
 
     when(dynamicConfigurationManager.getConfiguration()).thenReturn(dynamicConfiguration);