Use SCID instead of PDU session id as parameter for timeout handler

src/smf_app/smf_app.cpp

@@ -273,7 +273,8 @@ void smf_app_task(void*) {
           Logger::smf_app().info("TIME-OUT event timer id %d", to->timer_id);
           switch (to->arg1_user) {
             case TASK_SMF_APP_TRIGGER_T3591:
-              smf_app_inst->timer_t3591_timeout(to->timer_id, to->arg2_user);
+              smf_app_inst->timer_t3591_timeout(
+                  to->timer_id, (scid_t) to->arg2_user);
               break;
             case TASK_SMF_APP_TIMEOUT_NRF_HEARTBEAT:
               smf_app_inst->timer_nrf_heartbeat_timeout(
@@ -1597,7 +1598,7 @@ void smf_app::update_pdu_session_upCnx_state(
       upCnx_state_e2str.at(static_cast<int>(state)).c_str());
 }
 //---------------------------------------------------------------------------------------------
-void smf_app::timer_t3591_timeout(timer_id_t timer_id, uint64_t arg2_user) {
+void smf_app::timer_t3591_timeout(timer_id_t timer_id, scid_t scid) {
   // TODO: send session modification request again...
 }
 

src/smf_app/smf_app.hpp

@@ -615,10 +615,10 @@ class smf_app {
   /*
    * will be executed when timer T3591 expires
    * @param [timer_id_t] timer_id
-   * @param [uint64_t] arg2_user
+   * @param [scid_t] scid
    * @return void
    */
-  void timer_t3591_timeout(timer_id_t timer_id, uint64_t arg2_user);
+  void timer_t3591_timeout(timer_id_t timer_id, scid_t scid);
 
   /*
    * will be executed when NRF Heartbeat timer expires

src/smf_app/smf_context.cpp

@@ -1792,11 +1792,21 @@ bool smf_context::handle_pdu_session_modification_request(
   // Update PDU Session status
   sp.get()->set_pdu_session_status(
       pdu_session_status_e::PDU_SESSION_MODIFICATION_PENDING);
+
+  scid_t scid = {};
+  try {
+    scid = std::stoi(sm_context_request.get()->scid);
+  } catch (const std::exception& err) {
+    Logger::smf_app().warn(
+        "Couldn't retrieve "
+        "the corresponding SMF context, ignore message!");
+    return false;
+  }
+
   // start timer T3591
   // get smf_pdu_session and set the corresponding timer
   sp.get()->timer_T3591 = itti_inst->timer_setup(
-      T3591_TIMER_VALUE_SEC, 0, TASK_SMF_APP, TASK_SMF_APP_TRIGGER_T3591,
-      sm_context_request.get()->req.get_pdu_session_id());
+      T3591_TIMER_VALUE_SEC, 0, TASK_SMF_APP, TASK_SMF_APP_TRIGGER_T3591, scid);
 
   free_wrapper((void**) &nas_msg.plain.sm.pdu_session_modification_request
                    .qosflowdescriptions.qosflowdescriptionscontents);