Flag RBs as suspended in PDCP

- this prevents pulling PDUs from PDCP when re-establishment is awaiting

openair2/LAYER2/nr_pdcp/nr_pdcp_entity.c

@@ -56,6 +56,11 @@ static void nr_pdcp_entity_recv_pdu(nr_pdcp_entity_t *entity,
   int              rx_deliv_sn;
   uint32_t         rx_deliv_hfn;
 
+  if (entity->entity_suspended) {
+    LOG_W(PDCP, "PDCP entity %d is suspended. Quit RX procedure.\n", entity->rb_id);
+    return;
+  }
+
   if (size < 1) {
     LOG_E(PDCP, "bad PDU received (size = %d)\n", size);
     return;
@@ -201,6 +206,12 @@ static int nr_pdcp_entity_process_sdu(nr_pdcp_entity_t *entity,
   char    *buf = pdu_buffer;
   DevAssert(nr_max_pdcp_pdu_size(size) <= pdu_max_size);
   int      dc_bit;
+
+  if (entity->entity_suspended) {
+    LOG_W(PDCP, "PDCP entity %d is suspended. Quit SDU processing.\n", entity->rb_id);
+    return -1;
+  }
+
   entity->stats.rxsdu_pkts++;
   entity->stats.rxsdu_bytes += size;
 
@@ -410,6 +421,7 @@ static void nr_pdcp_entity_suspend(nr_pdcp_entity_t *entity)
   }
   entity->rx_next = 0;
   entity->rx_deliv = 0;
+  entity->entity_suspended = true;
 }
 
 static void free_rx_list(nr_pdcp_entity_t *entity)
@@ -437,6 +449,9 @@ static void nr_pdcp_entity_reestablish_drb_am(nr_pdcp_entity_t *entity)
 
   /* receiving entity procedures */
   /* todo: deal with ciphering/integrity algos and keys */
+
+  /* Flag PDCP entity as re-established */
+  entity->entity_suspended = false;
 }
 
 static void nr_pdcp_entity_reestablish_drb_um(nr_pdcp_entity_t *entity)
@@ -455,6 +470,9 @@ static void nr_pdcp_entity_reestablish_drb_um(nr_pdcp_entity_t *entity)
   entity->rx_next = 0;
   entity->rx_deliv = 0;
   /* todo: deal with ciphering/integrity algos and keys */
+
+  /* Flag PDCP entity as re-established */
+  entity->entity_suspended = false;
 }
 
 static void nr_pdcp_entity_reestablish_srb(nr_pdcp_entity_t *entity)
@@ -471,6 +489,9 @@ static void nr_pdcp_entity_reestablish_srb(nr_pdcp_entity_t *entity)
   entity->rx_next = 0;
   entity->rx_deliv = 0;
   /* todo: deal with ciphering/integrity algos and keys */
+
+  /* Flag PDCP entity as re-established */
+  entity->entity_suspended = false;
 }
 
 static void nr_pdcp_entity_release(nr_pdcp_entity_t *entity)

openair2/LAYER2/nr_pdcp/nr_pdcp_entity.h

@@ -179,6 +179,9 @@ typedef struct nr_pdcp_entity_t {
   // 4- The ITTI task, forwards the message ciphering (e.g., nea2) it. 
   // 5- The gNB cannot understand the ciphered Security Mode Complete message.
   bool security_mode_completed;
+
+  /* Keep tracks of whether the PDCP entity was suspended or not */
+  bool entity_suspended;
 } nr_pdcp_entity_t;
 
 nr_pdcp_entity_t *new_nr_pdcp_entity(

openair2/LAYER2/nr_pdcp/nr_pdcp_oai_api.c

@@ -1087,6 +1087,10 @@ bool nr_pdcp_data_req_srb(ue_id_t ue_id,
   int max_size = nr_max_pdcp_pdu_size(sdu_buffer_size);
   char pdu_buf[max_size];
   int pdu_size = rb->process_sdu(rb, (char *)sdu_buffer, sdu_buffer_size, muiP, pdu_buf, max_size);
+  if (pdu_size == -1) {
+    nr_pdcp_manager_unlock(nr_pdcp_ue_manager);
+    return 0;
+  }
   AssertFatal(rb->deliver_pdu == NULL, "SRB callback should be NULL, to be provided on every invocation\n");
 
   nr_pdcp_manager_unlock(nr_pdcp_ue_manager);
@@ -1107,6 +1111,7 @@ void nr_pdcp_suspend_srb(ue_id_t ue_id, int srb_id)
     return;
   }
   srb->suspend_entity(srb);
+  LOG_D(PDCP, "SRB %d suspended\n", srb_id);
   nr_pdcp_manager_unlock(nr_pdcp_ue_manager);
 }
 
@@ -1121,6 +1126,7 @@ void nr_pdcp_suspend_drb(ue_id_t ue_id, int drb_id)
     return;
   }
   drb->suspend_entity(drb);
+  LOG_D(PDCP, "DRB %d suspended\n", drb_id);
   nr_pdcp_manager_unlock(nr_pdcp_ue_manager);
 }
 
@@ -1220,6 +1226,7 @@ void nr_pdcp_reestablishment(ue_id_t ue_id, int rb_id, bool srb_flag)
   if (rb != NULL) {
     LOG_D(PDCP, "UE %4.4lx re-establishment of %sRB %d\n", ue_id, srb_flag ? "S" : "D", rb_id);
     rb->reestablish_entity(rb);
+    LOG_I(PDCP, "%s %d re-established\n", srb_flag ? "SRB" : "DRB" , rb_id);
   } else {
     LOG_W(PDCP, "UE %4.4lx cannot re-establish %sRB %d, RB not found\n", ue_id, srb_flag ? "S" : "D", rb_id);
   }
@@ -1261,7 +1268,7 @@ bool nr_pdcp_data_req_drb(protocol_ctxt_t *ctxt_pP,
   rb = nr_pdcp_get_rb(ue, rb_id, false);
 
   if (rb == NULL) {
-    LOG_E(PDCP, "no DRB found (ue_id %lx, rb_id %ld)\n", ue_id, rb_id);
+    LOG_E(PDCP, "[UE %lx] DRB %ld not found\n", rb_id, ue_id);
     nr_pdcp_manager_unlock(nr_pdcp_ue_manager);
     return 0;
   }
@@ -1269,6 +1276,11 @@ bool nr_pdcp_data_req_drb(protocol_ctxt_t *ctxt_pP,
   int max_size = nr_max_pdcp_pdu_size(sdu_buffer_size);
   char pdu_buf[max_size];
   int pdu_size = rb->process_sdu(rb, (char *)sdu_buffer, sdu_buffer_size, muiP, pdu_buf, max_size);
+  if (pdu_size == -1) {
+    nr_pdcp_manager_unlock(nr_pdcp_ue_manager);
+    return 0;
+  }
+
   deliver_pdu deliver_pdu_cb = rb->deliver_pdu;
 
   nr_pdcp_manager_unlock(nr_pdcp_ue_manager);