Add option to enable unique network flow

- Option enabled for publishers and subscriptions
- TODO: Discuss error handling if not supported

Signed-off-by: Ananya Muddukrishna <ananya.x.muddukrishna@ericsson.com>

rclcpp/include/rclcpp/publisher_options.hpp

@@ -45,6 +45,9 @@ struct PublisherOptionsBase
   /// Whether or not to use default callbacks when user doesn't supply any in event_callbacks
   bool use_default_callbacks = true;
 
+  /// True to generate unique network flow
+  bool unique_network_flow = false;
+
   /// Callback group in which the waitable items from the publisher should be placed.
   std::shared_ptr<rclcpp::CallbackGroup> callback_group;
 
@@ -80,6 +83,7 @@ struct PublisherOptionsWithAllocator : public PublisherOptionsBase
     auto message_alloc = std::make_shared<MessageAllocatorT>(*this->get_allocator().get());
     result.allocator = rclcpp::allocator::get_rcl_allocator<MessageT>(*message_alloc);
     result.qos = qos.get_rmw_qos_profile();
+    result.rmw_publisher_options.unique_network_flow = this->unique_network_flow;
 
     // Apply payload to rcl_publisher_options if necessary.
     if (rmw_implementation_payload && rmw_implementation_payload->has_been_customized()) {

rclcpp/include/rclcpp/subscription_options.hpp

@@ -45,6 +45,9 @@ struct SubscriptionOptionsBase
   /// True to ignore local publications.
   bool ignore_local_publications = false;
 
+  /// True to generate unique network flow
+  bool unique_network_flow = false;
+
   /// The callback group for this subscription. NULL to use the default callback group.
   rclcpp::CallbackGroup::SharedPtr callback_group = nullptr;
 
@@ -108,6 +111,7 @@ struct SubscriptionOptionsWithAllocator : public SubscriptionOptionsBase
     result.allocator = allocator::get_rcl_allocator<MessageT>(*message_alloc);
     result.qos = qos.get_rmw_qos_profile();
     result.rmw_subscription_options.ignore_local_publications = this->ignore_local_publications;
+    result.rmw_subscription_options.unique_network_flow = this->unique_network_flow;
 
     // Apply payload to rcl_subscription_options if necessary.
     if (rmw_implementation_payload && rmw_implementation_payload->has_been_customized()) {