FlexRAN: Circumvent different RRC/MAC layer user ID sorting

* RRC and MAC might sort users differently
* therefore, we have to "reverse lookup" the MAC ID from the RNTI when filling
  user info
* For this purpose, add RAN API function flexran_get_mac_ue_id_rnti()

openair2/ENB_APP/flexran_agent_common.c

@@ -558,7 +558,8 @@ int flexran_agent_ue_config_reply(mid_t mod_id, const void *params, Protocol__Fl
 
   if (flexran_agent_get_rrc_xface(mod_id) && flexran_agent_get_mac_xface(mod_id)
       && flexran_get_rrc_num_ues(mod_id) != flexran_get_mac_num_ues(mod_id)) {
-    LOG_E(FLEXRAN_AGENT, "different numbers of UEs in RRC and MAC\n");
+    LOG_E(FLEXRAN_AGENT, "different numbers of UEs in RRC (%d) and MAC (%d)\n",
+        flexran_get_rrc_num_ues(mod_id), flexran_get_mac_num_ues(mod_id));
     goto error;
   }
 
@@ -578,7 +579,7 @@ int flexran_agent_ue_config_reply(mid_t mod_id, const void *params, Protocol__Fl
       if (flexran_agent_get_rrc_xface(mod_id))
         flexran_agent_fill_rrc_ue_config(mod_id, rnti, ue_config[i]);
       if (flexran_agent_get_mac_xface(mod_id)) {
-        const int UE_id = flexran_get_mac_ue_id(mod_id, i);
+        const int UE_id = flexran_get_mac_ue_id_rnti(mod_id, rnti);
         flexran_agent_fill_mac_ue_config(mod_id, UE_id, ue_config[i]);
       }
     }

openair2/ENB_APP/flexran_agent_handler.c

@@ -249,7 +249,8 @@ int flexran_agent_handle_stats(mid_t mod_id, const void *params, Protocol__Flexr
 
       if (flexran_agent_get_rrc_xface(mod_id) && flexran_agent_get_mac_xface(mod_id)
           && flexran_get_rrc_num_ues(mod_id) != flexran_get_mac_num_ues(mod_id)) {
-        LOG_E(FLEXRAN_AGENT, "different numbers of UEs in RRC and MAC\n");
+        LOG_E(FLEXRAN_AGENT, "different numbers of UEs in RRC (%d) and MAC (%d)\n",
+            flexran_get_rrc_num_ues(mod_id), flexran_get_mac_num_ues(mod_id));
         goto error;
       }
       report_config.ue_report_type = malloc(sizeof(ue_report_type_t) * report_config.nr_ue);

openair2/ENB_APP/flexran_agent_ran_api.c

@@ -129,6 +129,21 @@ int flexran_get_num_ue_lcs(mid_t mod_id, mid_t ue_id)
     return 3;
 }
 
+int flexran_get_mac_ue_id_rnti(mid_t mod_id, rnti_t rnti)
+{
+  int n;
+  if (!mac_is_present(mod_id)) return 0;
+  /* get the (active) UE with RNTI i */
+  for (n = 0; n < MAX_MOBILES_PER_ENB; ++n) {
+    if (RC.mac[mod_id]->UE_list.active[n] == TRUE
+        && rnti == UE_RNTI(mod_id, n)) {
+      return n;
+    }
+  }
+  return 0;
+
+}
+
 int flexran_get_mac_ue_id(mid_t mod_id, int i)
 {
   int n;

openair2/ENB_APP/flexran_agent_ran_api.h

@@ -80,6 +80,8 @@ int flexran_get_num_ue_lcs(mid_t mod_id, mid_t ue_id);
 /* Get the rnti of a UE with id ue_id from MAC */
 rnti_t flexran_get_mac_ue_crnti(mid_t mod_id, mid_t ue_id);
 
+int flexran_get_mac_ue_id_rnti(mid_t mod_id, rnti_t rnti);
+
 /* Return the UE id of attached UE as opposed to the index [0,NUM UEs] (i.e.,
  * the i'th active UE). Returns 0 if the i'th active UE could not be found. */
 int flexran_get_mac_ue_id(mid_t mod_id, int i);