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/**
*
* \section COPYRIGHT
*
* Copyright 2013-2020 Software Radio Systems Limited
*
* By using this file, you agree to the terms and conditions set
* forth in the LICENSE file which can be found at the top level of
* the distribution.
*
*/
#ifndef SRSLTE_PDCP_ENTITY_BASE_H
#define SRSLTE_PDCP_ENTITY_BASE_H
#include "srslte/common/buffer_pool.h"
#include "srslte/common/common.h"
#include "srslte/common/interfaces_common.h"
#include "srslte/common/logmap.h"
#include "srslte/common/security.h"
#include "srslte/common/task_scheduler.h"
#include "srslte/common/threads.h"
#include "srslte/common/timers.h"
#include "srslte/interfaces/pdcp_interface_types.h"
#include "srslte/upper/byte_buffer_queue.h"
namespace srslte {
/****************************************************************************
* Structs and Defines common to both LTE and NR
* Ref: 3GPP TS 36.323 v10.1.0 and TS 38.323 v15.2.0
***************************************************************************/
#define PDCP_PDU_TYPE_PDCP_STATUS_REPORT 0x0
#define PDCP_PDU_TYPE_INTERSPERSED_ROHC_FEEDBACK_PACKET 0x1
// Maximum supported PDCP SDU size is 9000 bytes.
// See TS 38.323 v15.2.0, section 4.3.1
#define PDCP_MAX_SDU_SIZE 9000
typedef enum {
PDCP_D_C_CONTROL_PDU = 0,
PDCP_D_C_DATA_PDU,
PDCP_D_C_N_ITEMS,
} pdcp_d_c_t;
static const char pdcp_d_c_text[PDCP_D_C_N_ITEMS][20] = {"Control PDU", "Data PDU"};
/****************************************************************************
* PDCP Entity interface
* Common interface for LTE and NR PDCP entities
***************************************************************************/
class pdcp_entity_base
{
public:
pdcp_entity_base(task_sched_handle task_sched_, srslog::basic_logger& logger);
pdcp_entity_base(pdcp_entity_base&&) = default;
virtual ~pdcp_entity_base();
virtual void reset() = 0;
virtual void reestablish() = 0;
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; }
// RRC interface
void enable_integrity(srslte_direction_t direction = DIRECTION_TXRX)
{
// if either DL or UL is already enabled, both are enabled
if (integrity_direction == DIRECTION_TX && direction == DIRECTION_RX) {
integrity_direction = DIRECTION_TXRX;
} else if (integrity_direction == DIRECTION_RX && direction == DIRECTION_TX) {
integrity_direction = DIRECTION_TXRX;
} else {
integrity_direction = direction;
}
logger.debug("LCID=%d, integrity=%s", lcid, srslte_direction_text[integrity_direction]);
}
void enable_encryption(srslte_direction_t direction = DIRECTION_TXRX)
{
// if either DL or UL is already enabled, both are enabled
if (encryption_direction == DIRECTION_TX && direction == DIRECTION_RX) {
encryption_direction = DIRECTION_TXRX;
} else if (encryption_direction == DIRECTION_RX && direction == DIRECTION_TX) {
encryption_direction = DIRECTION_TXRX;
} else {
encryption_direction = direction;
}
logger.debug("LCID=%d encryption=%s", lcid, srslte_direction_text[integrity_direction]);
}
void enable_security_timed(srslte_direction_t direction, uint32_t sn)
{
switch (direction) {
case DIRECTION_TX:
enable_security_tx_sn = sn;
break;
case DIRECTION_RX:
enable_security_rx_sn = sn;
break;
default:
logger.error("Timed security activation for direction %s not supported.", srslte_direction_text[direction]);
break;
}
}
void config_security(as_security_config_t sec_cfg_);
// GW/SDAP/RRC interface
virtual void write_sdu(unique_byte_buffer_t sdu) = 0;
// RLC interface
virtual void write_pdu(unique_byte_buffer_t pdu) = 0;
virtual void notify_delivery(const std::vector<uint32_t>& tx_count) = 0;
virtual void get_bearer_state(pdcp_lte_state_t* state) = 0;
virtual void set_bearer_state(const pdcp_lte_state_t& state) = 0;
virtual std::map<uint32_t, srslte::unique_byte_buffer_t> get_buffered_pdus() = 0;
// COUNT, HFN and SN helpers
uint32_t HFN(uint32_t count);
uint32_t SN(uint32_t count);
uint32_t COUNT(uint32_t hfn, uint32_t sn);
protected:
srslog::basic_logger& logger;
srslte::task_sched_handle task_sched;
bool active = false;
uint32_t lcid = 0;
srslte_direction_t integrity_direction = DIRECTION_NONE;
srslte_direction_t encryption_direction = DIRECTION_NONE;
int32_t enable_security_tx_sn = -1; // TX SN at which security will be enabled
int32_t enable_security_rx_sn = -1; // RX SN at which security will be enabled
pdcp_config_t cfg = {1,
PDCP_RB_IS_DRB,
SECURITY_DIRECTION_DOWNLINK,
SECURITY_DIRECTION_UPLINK,
PDCP_SN_LEN_12,
pdcp_t_reordering_t::ms500,
pdcp_discard_timer_t::infinity};
srslte::as_security_config_t sec_cfg = {};
// Security functions
void integrity_generate(uint8_t* msg, uint32_t msg_len, uint32_t count, uint8_t* mac);
bool integrity_verify(uint8_t* msg, uint32_t msg_len, uint32_t count, uint8_t* mac);
void cipher_encrypt(uint8_t* msg, uint32_t msg_len, uint32_t count, uint8_t* ct);
void cipher_decrypt(uint8_t* ct, uint32_t ct_len, uint32_t count, uint8_t* msg);
// Common packing functions
bool is_control_pdu(const unique_byte_buffer_t& pdu);
uint32_t read_data_header(const unique_byte_buffer_t& pdu);
void discard_data_header(const unique_byte_buffer_t& pdu);
void write_data_header(const srslte::unique_byte_buffer_t& sdu, uint32_t count);
void extract_mac(const unique_byte_buffer_t& pdu, uint8_t* mac);
void append_mac(const unique_byte_buffer_t& sdu, uint8_t* mac);
};
inline uint32_t pdcp_entity_base::HFN(uint32_t count)
{
return (count >> cfg.sn_len);
}
inline uint32_t pdcp_entity_base::SN(uint32_t count)
{
return count & (0xFFFFFFFF >> (32 - cfg.sn_len));
}
inline uint32_t pdcp_entity_base::COUNT(uint32_t hfn, uint32_t sn)
{
return (hfn << cfg.sn_len) | sn;
}
} // namespace srslte
#endif // SRSLTE_PDCP_ENTITY_BASE_H