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C++

/**
* Copyright 2013-2021 Software Radio Systems Limited
*
* This file is part of srsRAN.
*
* srsRAN is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of
* the License, or (at your option) any later version.
*
* srsRAN is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* A copy of the GNU Affero General Public License can be found in
* the LICENSE file in the top-level directory of this distribution
* and at http://www.gnu.org/licenses/.
*
*/
#ifndef SRSRAN_PDCP_ENTITY_LTE_H
#define SRSRAN_PDCP_ENTITY_LTE_H
#include "srsran/adt/circular_array.h"
#include "srsran/common/buffer_pool.h"
#include "srsran/common/common.h"
#include "srsran/common/security.h"
#include "srsran/common/threads.h"
#include "srsran/interfaces/ue_rrc_interfaces.h"
#include "srsran/upper/pdcp_entity_base.h"
namespace srsue {
class gw_interface_pdcp;
class rlc_interface_pdcp;
} // namespace srsue
namespace srsran {
class undelivered_sdus_queue
{
public:
explicit undelivered_sdus_queue(srsran::task_sched_handle task_sched);
bool empty() const { return count == 0; }
bool is_full() const { return count >= capacity; }
uint32_t size() const { return count; }
static uint32_t get_capacity() { return capacity; }
bool has_sdu(uint32_t sn) const
{
assert(sn != invalid_sn && "provided PDCP SN is invalid");
return sdus[sn].sdu != nullptr and sdus[sn].sdu->md.pdcp_sn == sn;
}
// Getter for the number of discard timers. Used for debugging.
size_t nof_discard_timers() const;
bool add_sdu(uint32_t sn,
const srsran::unique_byte_buffer_t& sdu,
uint32_t discard_timeout,
srsran::move_callback<void(uint32_t)> callback);
unique_byte_buffer_t& operator[](uint32_t sn)
{
assert(has_sdu(sn));
return sdus[sn].sdu;
}
bool clear_sdu(uint32_t sn);
void clear();
uint32_t get_bytes() const { return bytes; }
uint32_t get_fms() const { return fms; }
void set_fms(uint32_t fms_) { fms = fms_; }
void update_fms();
void update_lms(uint32_t sn);
uint32_t get_lms() const { return lms; }
std::map<uint32_t, srsran::unique_byte_buffer_t> get_buffered_sdus();
private:
const static uint32_t capacity = 4096;
const static uint32_t invalid_sn = -1;
static uint32_t increment_sn(uint32_t sn) { return (sn + 1) % capacity; }
struct sdu_data {
srsran::unique_byte_buffer_t sdu;
srsran::unique_timer discard_timer;
};
uint32_t count = 0;
uint32_t bytes = 0;
uint32_t fms = 0; // SN of the first missing PDCP SDU
uint32_t lms = 0;
srsran::circular_array<sdu_data, capacity> sdus;
};
/****************************************************************************
* Structs and Defines
* Ref: 3GPP TS 36.323 v10.1.0
***************************************************************************/
#define PDCP_CONTROL_MAC_I 0x00000000
/****************************************************************************
* LTE PDCP Entity
* Class for LTE PDCP entities
***************************************************************************/
class pdcp_entity_lte final : public pdcp_entity_base
{
public:
pdcp_entity_lte(srsue::rlc_interface_pdcp* rlc_,
srsue::rrc_interface_pdcp* rrc_,
srsue::gw_interface_pdcp* gw_,
srsran::task_sched_handle task_sched_,
srslog::basic_logger& logger,
uint32_t lcid_);
~pdcp_entity_lte() override;
bool configure(const pdcp_config_t& cnfg_) override;
void reset() override;
void reestablish() override;
// GW/RRC interface
void write_sdu(unique_byte_buffer_t sdu, int sn = -1) override;
// RLC interface
void write_pdu(unique_byte_buffer_t pdu) override;
void notify_failure(const pdcp_sn_vector_t& pdcp_sns) override;
void notify_delivery(const pdcp_sn_vector_t& pdcp_sns) override;
// Config helpers
bool check_valid_config();
// TX SDU queue helper
bool store_sdu(uint32_t tx_count, const unique_byte_buffer_t& pdu);
// Getter for unacknowledged PDUs. Used for handover
std::map<uint32_t, srsran::unique_byte_buffer_t> get_buffered_pdus() override;
// Status report helper(s)
void send_status_report() override;
void handle_status_report_pdu(srsran::unique_byte_buffer_t pdu);
// Internal state getters/setters
void get_bearer_state(pdcp_lte_state_t* state) override;
void set_bearer_state(const pdcp_lte_state_t& state, bool set_fmc) override;
// Metrics helpers
pdcp_bearer_metrics_t get_metrics() override;
void reset_metrics() override;
size_t nof_discard_timers() const { return undelivered_sdus != nullptr ? undelivered_sdus->nof_discard_timers() : 0; }
private:
srsue::rlc_interface_pdcp* rlc = nullptr;
srsue::rrc_interface_pdcp* rrc = nullptr;
srsue::gw_interface_pdcp* gw = nullptr;
// State variables, as defined in TS 36 323, section 7.1
pdcp_lte_state_t st = {};
uint32_t reordering_window = 0;
uint32_t maximum_pdcp_sn = 0;
// PDU handlers
void handle_control_pdu(srsran::unique_byte_buffer_t pdu);
void handle_srb_pdu(srsran::unique_byte_buffer_t pdu);
void handle_um_drb_pdu(srsran::unique_byte_buffer_t pdu);
void handle_am_drb_pdu(srsran::unique_byte_buffer_t pdu);
// Discard callback (discardTimer)
class discard_callback;
// Tx info queue
uint32_t maximum_allocated_sns_window = 2048;
std::unique_ptr<undelivered_sdus_queue> undelivered_sdus;
// Rx info queue
uint32_t fmc = 0;
uint32_t largest_rx_count = 0;
std::vector<uint32_t> rx_counts_info; // Keeps the RX_COUNT for generation of the stauts report
void update_rx_counts_queue(uint32_t rx_count);
/*
* Helper function to see if an SN is larger
*/
bool is_sn_larger(uint32_t sn1, uint32_t sn2)
{
int32_t diff = sn2 - sn1;
uint32_t nof_sns = 1u << cfg.sn_len;
if (diff > (int32_t)(nof_sns / 2)) {
return false;
}
if (diff <= 0 && diff > -((int32_t)(nof_sns / 2))) {
return false;
}
return true;
}
};
// Discard callback (discardTimer)
class pdcp_entity_lte::discard_callback
{
public:
discard_callback(pdcp_entity_lte* parent_, uint32_t sn_)
{
parent = parent_;
discard_sn = sn_;
};
void operator()(uint32_t timer_id);
private:
pdcp_entity_lte* parent;
uint32_t discard_sn;
};
} // namespace srsran
#endif // SRSRAN_PDCP_ENTITY_LTE_H