From 88af2860a2966b169989835417f4e5268ee84e10 Mon Sep 17 00:00:00 2001
From: francescomani <email@francescomani.it>
Date: Thu, 9 Jan 2025 19:21:36 +0100
Subject: [PATCH] handle RRC reject at UE

---
 openair2/LAYER2/NR_MAC_UE/config_ue.c |  5 ++++
 openair2/LAYER2/NR_MAC_UE/mac_defs.h  |  2 ++
 openair2/LAYER2/NR_MAC_UE/mac_proto.h |  5 +---
 openair2/RRC/NR_UE/rrc_UE.c           | 41 +++++++++++++++++++++++++--
 4 files changed, 47 insertions(+), 6 deletions(-)

diff --git a/openair2/LAYER2/NR_MAC_UE/config_ue.c b/openair2/LAYER2/NR_MAC_UE/config_ue.c
index bfea78d540..9bdbeebe10 100644
--- a/openair2/LAYER2/NR_MAC_UE/config_ue.c
+++ b/openair2/LAYER2/NR_MAC_UE/config_ue.c
@@ -1725,6 +1725,11 @@ void nr_rrc_mac_config_req_reset(module_id_t module_id, NR_UE_MAC_reset_cause_t
       reset_mac_inst(mac);
       mac->state = UE_PERFORMING_RA; // still in sync but need to restart RA
       break;
+    case REJECT:
+      reset_ra(mac, false);
+      reset_mac_inst(mac);
+      mac->state = UE_BARRED;
+      break;
     case RE_ESTABLISHMENT:
       reset_mac_inst(mac);
       nr_ue_mac_default_configs(mac);
diff --git a/openair2/LAYER2/NR_MAC_UE/mac_defs.h b/openair2/LAYER2/NR_MAC_UE/mac_defs.h
index dee2a30c08..0174e88abc 100644
--- a/openair2/LAYER2/NR_MAC_UE/mac_defs.h
+++ b/openair2/LAYER2/NR_MAC_UE/mac_defs.h
@@ -148,6 +148,7 @@
 // Define the UE L2 states with X-Macro
 #define NR_UE_L2_STATES \
   UE_STATE(UE_NOT_SYNC) \
+  UE_STATE(UE_BARRED) \
   UE_STATE(UE_RECEIVING_SIB) \
   UE_STATE(UE_PERFORMING_RA) \
   UE_STATE(UE_CONNECTED) \
@@ -199,6 +200,7 @@ typedef enum {
   RE_ESTABLISHMENT,
   RRC_SETUP_REESTAB_RESUME,
   UL_SYNC_LOST_T430_EXPIRED,
+  REJECT,
 } NR_UE_MAC_reset_cause_t;
 
 typedef struct {
diff --git a/openair2/LAYER2/NR_MAC_UE/mac_proto.h b/openair2/LAYER2/NR_MAC_UE/mac_proto.h
index c8eab85462..0a7365ef5d 100644
--- a/openair2/LAYER2/NR_MAC_UE/mac_proto.h
+++ b/openair2/LAYER2/NR_MAC_UE/mac_proto.h
@@ -87,10 +87,7 @@ void nr_rrc_mac_config_req_cg(module_id_t module_id,
                               NR_CellGroupConfig_t *cell_group_config,
                               NR_UE_NR_Capability_t *ue_Capability);
 
-void nr_rrc_mac_config_req_mib(module_id_t module_id,
-                               int cc_idP,
-                               NR_MIB_t *mibP,
-                               int sched_sib1);
+void nr_rrc_mac_config_req_mib(module_id_t module_id, int cc_idP, NR_MIB_t *mibP, int sched_sib1);
 
 void nr_rrc_mac_config_req_sib1(module_id_t module_id, int cc_idP, NR_SIB1_t *sib1, bool can_start_ra);
 
diff --git a/openair2/RRC/NR_UE/rrc_UE.c b/openair2/RRC/NR_UE/rrc_UE.c
index 90713ff50c..af0c1350c1 100644
--- a/openair2/RRC/NR_UE/rrc_UE.c
+++ b/openair2/RRC/NR_UE/rrc_UE.c
@@ -1394,8 +1394,44 @@ static void nr_rrc_process_rrcsetup(NR_UE_RRC_INST_t *rrc, const NR_RRCSetup_t *
   rrc_ue_generate_RRCSetupComplete(rrc, rrcSetup->rrc_TransactionIdentifier);
 }
 
-static int8_t nr_rrc_ue_decode_ccch(NR_UE_RRC_INST_t *rrc,
-                                    const NRRrcMacCcchDataInd *ind)
+static void nr_rrc_process_rrcreject(NR_UE_RRC_INST_t *rrc, const NR_RRCReject_t *rrcReject)
+{
+  // stop timer T300, T302, T319 if running;
+  NR_UE_Timers_Constants_t *timers = &rrc->timers_and_constants;
+  nr_timer_stop(&timers->T300);
+  nr_timer_stop(&timers->T302);
+  nr_timer_stop(&timers->T319);
+
+  // reset MAC and release the default MAC Cell Group configuration
+  NR_UE_MAC_reset_cause_t cause = REJECT;
+  MessageDef *msg = itti_alloc_new_message(TASK_RRC_NRUE, 0, NR_MAC_RRC_CONFIG_RESET);
+  NR_MAC_RRC_CONFIG_RESET(msg).cause = cause;
+  itti_send_msg_to_task(TASK_MAC_UE, rrc->ue_id, msg);
+
+  // if waitTime is configured in the RRCReject: start timer T302, with the timer value set to the waitTime
+  NR_RejectWaitTime_t *waitTime = NULL;
+  if (rrcReject->criticalExtensions.present == NR_RRCReject__criticalExtensions_PR_rrcReject) {
+    NR_RRCReject_IEs_t *ies = rrcReject->criticalExtensions.choice.rrcReject;
+    waitTime = ies->waitTime; // Wait time value in seconds
+  }
+  if (waitTime) {
+    nr_timer_setup(&timers->T302, *waitTime * 1000, 10);
+    nr_timer_start(&timers->T302);
+  } else {
+    LOG_W(RRC, "Error: waitTime should be always included in RRCReject message\n");
+  }
+
+  // TODO if RRCReject is received in response to a request from upper layers
+  //      inform the upper layer that access barring is applicable for all access categories except categories '0' and '2'
+
+  // TODO if RRCReject is received in response to an RRCSetupRequest
+  //      inform upper layers about the failure to setup the RRC connection, upon which the procedure ends
+
+  // TODO else if RRCReject is received in response to an RRCResumeRequest or an RRCResumeRequest1
+  //      Resume not implemented yet
+}
+
+static int8_t nr_rrc_ue_decode_ccch(NR_UE_RRC_INST_t *rrc, const NRRrcMacCcchDataInd *ind)
 {
   NR_DL_CCCH_Message_t *dl_ccch_msg = NULL;
   asn_dec_rval_t dec_rval;
@@ -1423,6 +1459,7 @@ static int8_t nr_rrc_ue_decode_ccch(NR_UE_RRC_INST_t *rrc,
 
        case NR_DL_CCCH_MessageType__c1_PR_rrcReject:
          LOG_I(NR_RRC, "[UE%ld] Logical Channel DL-CCCH (SRB0), Received RRCReject \n", rrc->ue_id);
+         nr_rrc_process_rrcreject(rrc, dl_ccch_msg->message.choice.c1->choice.rrcReject);
          rval = 0;
          break;