cu_cp,f1ap: Add srb id to ue context release request with rrc container

Author: FabianEckermann

include/srsran/f1ap/cu_cp/f1ap_cu.h

@@ -60,9 +60,10 @@ class f1ap_connection_manager
 };
 
 struct f1ap_ue_context_release_command {
-  ue_index_t  ue_index = ue_index_t::invalid;
-  cause_t     cause;
-  byte_buffer rrc_release_pdu;
+  ue_index_t         ue_index = ue_index_t::invalid;
+  cause_t            cause;
+  byte_buffer        rrc_release_pdu;
+  optional<srb_id_t> srb_id;
 };
 
 struct f1ap_ue_context_release_complete {

include/srsran/rrc/rrc_ue.h

@@ -170,9 +170,10 @@ class rrc_ue_reestablishment_proc_notifier
 };
 
 struct rrc_ue_context_release_command {
-  ue_index_t  ue_index = ue_index_t::invalid;
-  cause_t     cause    = cause_t::nulltype;
-  byte_buffer rrc_release_pdu;
+  ue_index_t         ue_index = ue_index_t::invalid;
+  cause_t            cause    = cause_t::nulltype;
+  byte_buffer        rrc_release_pdu;
+  optional<srb_id_t> srb_id;
 };
 
 /// Interface to notify about RRC UE Context messages.
@@ -265,6 +266,7 @@ class rrc_ue_dl_nas_message_handler
 struct rrc_ue_release_context {
   cu_cp_user_location_info_nr user_location_info;
   byte_buffer                 rrc_release_pdu;
+  srb_id_t                    srb_id = srb_id_t::nulltype;
 };
 
 /// Handle control messages.

lib/cu_cp/du_processor_impl.cpp

@@ -465,6 +465,7 @@ du_processor_impl::handle_new_ue_context_release_command(const cu_cp_ngap_ue_con
   release_command.ue_index        = cmd.ue_index;
   release_command.cause           = cmd.cause;
   release_command.rrc_release_pdu = release_context.rrc_release_pdu.copy();
+  release_command.srb_id          = release_context.srb_id;
 
   handle_ue_context_release_command(release_command);
 

lib/cu_cp/routines/ue_context_release_routine.cpp

@@ -52,6 +52,7 @@ void ue_context_release_routine::operator()(coro_context<async_task<void>>& ctx)
     f1ap_ue_context_release_cmd.ue_index        = command.ue_index;
     f1ap_ue_context_release_cmd.cause           = command.cause;
     f1ap_ue_context_release_cmd.rrc_release_pdu = command.rrc_release_pdu.copy();
+    f1ap_ue_context_release_cmd.srb_id          = command.srb_id;
 
     CORO_AWAIT_VALUE(f1ap_ue_context_release_result,
                      f1ap_ue_ctxt_notifier.on_ue_context_release_command(f1ap_ue_context_release_cmd));

lib/f1ap/cu_cp/procedures/ue_context_release_procedure.cpp

@@ -10,6 +10,8 @@
 
 #include "ue_context_release_procedure.h"
 #include "../f1ap_asn1_converters.h"
+#include "srsran/ran/lcid.h"
+#include "srsran/support/srsran_assert.h"
 
 using namespace srsran;
 using namespace srsran::srs_cu_cp;
@@ -27,6 +29,11 @@ ue_context_release_procedure::ue_context_release_procedure(f1ap_ue_context_list&
   if (!cmd_.rrc_release_pdu.empty()) {
     command->rrc_container_present = true;
     command->rrc_container         = cmd_.rrc_release_pdu.copy();
+
+    srsran_assert(cmd_.srb_id.has_value(), "SRB-ID for UE Context Release Command with RRC Container must be set.");
+
+    command->srb_id_present = true;
+    command->srb_id         = srb_id_to_uint(cmd_.srb_id.value());
   }
 }
 

lib/rrc/ue/rrc_ue_message_handlers.cpp

@@ -15,6 +15,7 @@
 #include "rrc_asn1_helpers.h"
 #include "rrc_ue_impl.h"
 #include "srsran/asn1/rrc_nr/nr_ue_variables.h"
+#include "srsran/ran/lcid.h"
 #include "srsran/security/integrity.h"
 
 using namespace srsran;
@@ -302,6 +303,7 @@ rrc_ue_release_context rrc_ue_impl::get_rrc_ue_release_context()
 
   // pack DL CCCH msg
   release_context.rrc_release_pdu = pack_into_pdu(dl_dcch_msg);
+  release_context.srb_id          = srb_id_t::srb1;
 
   return release_context;
 }

tests/unittests/cu_cp/cu_cp_test.cpp

@@ -498,6 +498,8 @@ TEST_F(cu_cp_test, when_release_command_received_then_release_command_is_sent_to
   ASSERT_EQ(f1ap_pdu_notifier.last_f1ap_msg.pdu.init_msg().value.type().value,
             asn1::f1ap::f1ap_elem_procs_o::init_msg_c::types_opts::ue_context_release_cmd);
   ASSERT_TRUE(f1ap_pdu_notifier.last_f1ap_msg.pdu.init_msg().value.ue_context_release_cmd()->rrc_container_present);
+  // check that the SRB ID is set if the RRC Container is included
+  ASSERT_TRUE(f1ap_pdu_notifier.last_f1ap_msg.pdu.init_msg().value.ue_context_release_cmd()->srb_id_present);
 }
 
 //////////////////////////////////////////////////////////////////////////////////////