Get network flows of publishers and subscriptions

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

rmw_implementation/src/functions.cpp

@@ -31,6 +31,7 @@
 #include "rmw/error_handling.h"
 #include "rmw/event.h"
 #include "rmw/names_and_types.h"
+#include "rmw/get_network_flow.h"
 #include "rmw/get_node_info_and_types.h"
 #include "rmw/get_service_names_and_types.h"
 #include "rmw/get_topic_endpoint_info.h"
@@ -599,6 +600,22 @@ RMW_INTERFACE_FN(
     bool,
     rmw_topic_endpoint_info_array_t *))
 
+RMW_INTERFACE_FN(
+  rmw_publisher_get_network_flow,
+  rmw_ret_t, RMW_RET_ERROR,
+  3, ARG_TYPES(
+    const rmw_publisher_t *,
+    rcutils_allocator_t *,
+    rmw_network_flow_array_t *))
+
+RMW_INTERFACE_FN(
+  rmw_subscription_get_network_flow,
+  rmw_ret_t, RMW_RET_ERROR,
+  3, ARG_TYPES(
+    const rmw_subscription_t *,
+    rcutils_allocator_t *,
+    rmw_network_flow_array_t *))
+
 #define GET_SYMBOL(x) symbol_ ## x = get_symbol(#x);
 
 void prefetch_symbols(void)
@@ -676,6 +693,8 @@ void prefetch_symbols(void)
   GET_SYMBOL(rmw_set_log_severity)
   GET_SYMBOL(rmw_get_publishers_info_by_topic)
   GET_SYMBOL(rmw_get_subscriptions_info_by_topic)
+  GET_SYMBOL(rmw_publisher_get_network_flow)
+  GET_SYMBOL(rmw_subscription_get_network_flow)
 }
 
 void * symbol_rmw_init = nullptr;
@@ -775,6 +794,8 @@ unload_library()
   symbol_rmw_set_log_severity = nullptr;
   symbol_rmw_get_publishers_info_by_topic = nullptr;
   symbol_rmw_get_subscriptions_info_by_topic = nullptr;
+  symbol_rmw_publisher_get_network_flow = nullptr;
+  symbol_rmw_subscription_get_network_flow = nullptr;
   symbol_rmw_init = nullptr;
   g_rmw_lib.reset();
 }