Fix Msg4 segmentation fault when UE_id is invalid and reset ul_failure when UE reconnects using C-RNTI

openair2/LAYER2/NR_MAC_COMMON/nr_mac_common.h

@@ -192,8 +192,13 @@ uint8_t get_transformPrecoding(const NR_BWP_UplinkCommon_t *initialUplinkBWP,
                                uint8_t configuredGrant);
 
 void nr_mac_gNB_rrc_ul_failure(const module_id_t Mod_instP,
-                            const int CC_idP,
-                            const frame_t frameP,
-                            const sub_frame_t subframeP,
-                            const rnti_t rntiP) ;
+                               const int CC_idP,
+                               const frame_t frameP,
+                               const sub_frame_t subframeP,
+                               const rnti_t rntiP);
+
+void nr_mac_gNB_rrc_ul_failure_reset(const module_id_t Mod_instP,
+                                     const frame_t frameP,
+                                     const sub_frame_t subframeP,
+                                     const rnti_t rntiP);
 #endif

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_RA.c

@@ -1412,12 +1412,6 @@ void nr_generate_Msg4(module_id_t module_idP, int CC_id, frame_t frameP, sub_fra
     }
 
     int UE_id = find_nr_UE_id(module_idP, ra->rnti);
-    if (UE_id < 0) {
-      mac_remove_nr_ue(module_idP, tc_rnti);
-      nr_clear_ra_proc(module_idP, CC_id, frameP, ra);
-      return;
-    }
-
     NR_UE_info_t *UE_info = &nr_mac->UE_info;
     NR_UE_sched_ctrl_t *sched_ctrl = &UE_info->UE_sched_ctrl[UE_id];
 

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c

@@ -822,6 +822,20 @@ void nr_rx_sdu(const module_id_t gnb_mod_idP,
             ra->state = Msg4;
             ra->Msg4_frame = (frameP + 2) % 1024;
             ra->Msg4_slot = 1;
+            
+            if (ra->msg3_dcch_dtch) {
+              // Check if the C-RNTI still exists in the network
+              int UE_id_C = find_nr_UE_id(gnb_mod_idP, ra->crnti);
+              if (UE_id_C < 0) {
+                mac_remove_nr_ue(gnb_mod_idP, ra->rnti);
+                nr_clear_ra_proc(gnb_mod_idP, CC_idP, frameP, ra);
+                return;
+              } else {
+                UE_info->UE_sched_ctrl[UE_id_C].pusch_consecutive_dtx_cnt = 0;
+                UE_info->UE_sched_ctrl[UE_id_C].ul_failure = 0;
+                nr_mac_gNB_rrc_ul_failure_reset(gnb_mod_idP, frameP, slotP, ra->crnti);
+              }
+            }
             LOG_I(NR_MAC, "Scheduling RA-Msg4 for TC_RNTI 0x%04x (state %d, frame %d, slot %d)\n",
                   (ra->msg3_dcch_dtch?ra->crnti:ra->rnti), ra->state, ra->Msg4_frame, ra->Msg4_slot);
           }

openair2/RRC/NR/L2_nr_interface.c

@@ -383,3 +383,17 @@ void nr_mac_gNB_rrc_ul_failure(const module_id_t Mod_instP,
     LOG_D(RRC,"Frame %d, Subframe %d: UL failure: UE %x unknown \n",frameP,subframeP,rntiP);
   }
 }
+
+void nr_mac_gNB_rrc_ul_failure_reset(const module_id_t Mod_instP,
+                                     const frame_t frameP,
+                                     const sub_frame_t subframeP,
+                                     const rnti_t rntiP) {
+  struct rrc_gNB_ue_context_s *ue_context_p = NULL;
+  ue_context_p = rrc_gNB_get_ue_context(RC.nrrrc[Mod_instP], rntiP);
+  if (ue_context_p != NULL) {
+    LOG_W(RRC,"Frame %d, Subframe %d: UE %x UL failure reset, deactivating timer\n",frameP,subframeP,rntiP);
+    ue_context_p->ue_context.ul_failure_timer=0;
+  } else {
+    LOG_W(RRC,"Frame %d, Subframe %d: UL failure reset: UE %x unknown \n",frameP,subframeP,rntiP);
+  }
+}