Stop PDCP for data bearers before initiating HO

lib/include/srsran/interfaces/enb_pdcp_interfaces.h

@@ -31,6 +31,7 @@ public:
 class pdcp_interface_rrc
 {
 public:
+  virtual void set_enabled(uint16_t rnti, uint32_t lcid, bool enable)                                                     = 0;
   virtual void reset(uint16_t rnti)                                                                        = 0;
   virtual void add_user(uint16_t rnti)                                                                     = 0;
   virtual void rem_user(uint16_t rnti)                                                                     = 0;

lib/include/srsran/interfaces/ue_pdcp_interfaces.h

@@ -24,6 +24,7 @@ public:
   virtual void reestablish()                                                                                        = 0;
   virtual void reestablish(uint32_t lcid)                                                                           = 0;
   virtual void reset()                                                                                              = 0;
+  virtual void set_enabled(uint32_t lcid, bool enabled)                                                             = 0;
   virtual void write_sdu(uint32_t lcid, srsran::unique_byte_buffer_t sdu, int sn = -1)                              = 0;
   virtual int  add_bearer(uint32_t lcid, srsran::pdcp_config_t cnfg)                                                = 0;
   virtual void del_bearer(uint32_t lcid)                                                                            = 0;

lib/include/srsran/upper/pdcp.h

@@ -36,6 +36,7 @@ public:
   void reestablish() override;
   void reestablish(uint32_t lcid) override;
   void reset() override;
+  void set_enabled(uint32_t lcid, bool enabled) override;
   void write_sdu(uint32_t lcid, unique_byte_buffer_t sdu, int sn = -1) override;
   void write_sdu_mch(uint32_t lcid, unique_byte_buffer_t sdu);
   int  add_bearer(uint32_t lcid, pdcp_config_t cnfg) override;

lib/include/srsran/upper/pdcp_entity_base.h

@@ -60,6 +60,7 @@ public:
   virtual void reset()                               = 0;
   virtual void reestablish()                         = 0;
 
+  void set_enabled(bool enabled) { active = enabled; }
   bool is_active() { return active; }
   bool is_srb() { return cfg.rb_type == PDCP_RB_IS_SRB; }
   bool is_drb() { return cfg.rb_type == PDCP_RB_IS_DRB; }

lib/src/pdcp/pdcp.cc

@@ -63,6 +63,15 @@ void pdcp::reset()
   pdcp_array.clear();
 }
 
+void pdcp::set_enabled(uint32_t lcid, bool enabled)
+{
+  if (valid_lcid(lcid)) {
+    pdcp_array.at(lcid)->set_enabled(enabled);
+  } else {
+    logger.warning("LCID %d doesn't exist while setting enabled", lcid);
+  }
+}
+
 /*******************************************************************************
   RRC/GW interface
 *******************************************************************************/

lib/src/pdcp/pdcp_entity_lte.cc

@@ -134,6 +134,11 @@ void pdcp_entity_lte::reset()
 // GW/RRC interface
 void pdcp_entity_lte::write_sdu(unique_byte_buffer_t sdu, int upper_sn)
 {
+  if (!active) {
+    logger.warning("Dropping %s SDU due to inactive bearer", rrc->get_rb_name(lcid));
+    return;
+  }
+
   if (rlc->sdu_queue_is_full(lcid)) {
     logger.info(sdu->msg, sdu->N_bytes, "Dropping %s SDU due to full queue", rrc->get_rb_name(lcid));
     return;
@@ -216,6 +221,11 @@ void pdcp_entity_lte::write_sdu(unique_byte_buffer_t sdu, int upper_sn)
 // RLC interface
 void pdcp_entity_lte::write_pdu(unique_byte_buffer_t pdu)
 {
+  if (!active) {
+    logger.warning("Dropping %s PDU due to inactive bearer", rrc->get_rb_name(lcid));
+    return;
+  }
+
   // Handle control PDUs
   if (is_drb() && is_control_pdu(pdu)) {
     logger.info("Handling PDCP control PDU");

srsenb/hdr/stack/upper/pdcp.h

@@ -44,6 +44,7 @@ public:
   void write_pdu_mch(uint32_t lcid, srsran::unique_byte_buffer_t sdu) {}
 
   // pdcp_interface_rrc
+  void set_enabled(uint16_t rnti, uint32_t lcid, bool enabled) override;
   void reset(uint16_t rnti) override;
   void add_user(uint16_t rnti) override;
   void rem_user(uint16_t rnti) override;

srsenb/src/stack/rrc/rrc_mobility.cc

@@ -700,7 +700,10 @@ void rrc::ue::rrc_mobility::s1_source_ho_st::handle_ho_cmd(wait_ho_cmd& s, const
   /* Enter Handover Execution */
   // TODO: Do anything with MeasCfg info within the Msg (e.g. update ue_var_meas)?
 
-  // Disable DRBs in the MAC, while Reconfiguration is taking place.
+  // Disable DRBs in the MAC and PDCP, while Reconfiguration is taking place.
+  for (const drb_to_add_mod_s& drb : rrc_ue->bearer_list.get_established_drbs()) {
+    rrc_ue->parent->pdcp->set_enabled(rrc_ue->rnti, drb_to_lcid((lte_drb)drb.drb_id), false);
+  }
   rrc_ue->mac_ctrl.set_drb_activation(false);
   rrc_ue->mac_ctrl.update_mac(mac_controller::proc_stage_t::other);
 

srsenb/src/stack/upper/pdcp.cc

@@ -86,6 +86,13 @@ void pdcp::del_bearer(uint16_t rnti, uint32_t lcid)
   }
 }
 
+void pdcp::set_enabled(uint16_t rnti, uint32_t lcid, bool enabled)
+{
+  if (users.count(rnti)) {
+    users[rnti].pdcp->set_enabled(lcid, enabled);
+  }
+}
+
 void pdcp::reset(uint16_t rnti)
 {
   if (users.count(rnti)) {

srsenb/test/common/dummy_classes_common.h

@@ -39,6 +39,7 @@ public:
 class pdcp_dummy : public pdcp_interface_rrc, public pdcp_interface_gtpu
 {
 public:
+  void set_enabled(uint16_t rnti, uint32_t lcid, bool enabled) override {}
   void reset(uint16_t rnti) override {}
   void add_user(uint16_t rnti) override {}
   void rem_user(uint16_t rnti) override {}

srsue/src/stack/rrc/test/ue_rrc_nr_test.cc

@@ -62,6 +62,7 @@ class dummy_rlc : public rlc_interface_rrc
 
 class dummy_pdcp : public pdcp_interface_rrc
 {
+  void set_enabled(uint32_t lcid, bool enabled) {};
   void reestablish(){};
   void reestablish(uint32_t lcid){};
   void reset(){};